From 4795a6be8bd46f0d291e34dea3eba38ca3f69013 Mon Sep 17 00:00:00 2001
From: Tyler Helmuth <12352919+TylerHelmuth@users.noreply.github.com>
Date: Tue, 2 Jul 2024 10:05:14 -0600
Subject: [PATCH 01/13] Deprecate expandconverter

---
 cmd/builder/internal/builder/templates/main.go.tmpl | 4 ----
 cmd/otelcorecol/go.mod                              | 1 -
 cmd/otelcorecol/main.go                             | 4 ----
 confmap/converter/expandconverter/expand.go         | 3 +++
 confmap/converter/expandconverter/go.mod            | 1 +
 otelcol/otelcoltest/config.go                       | 2 --
 6 files changed, 4 insertions(+), 11 deletions(-)

diff --git a/cmd/builder/internal/builder/templates/main.go.tmpl b/cmd/builder/internal/builder/templates/main.go.tmpl
index a1bb7b532dc..b167f1800e8 100644
--- a/cmd/builder/internal/builder/templates/main.go.tmpl
+++ b/cmd/builder/internal/builder/templates/main.go.tmpl
@@ -9,7 +9,6 @@ import (
 	"go.opentelemetry.io/collector/component"
 	{{- if .Distribution.SupportsConfmapFactories}}
 	"go.opentelemetry.io/collector/confmap"
-	"go.opentelemetry.io/collector/confmap/converter/expandconverter"
 	{{- range .Providers}}
 	{{.Name}} "{{.Import}}"
 	{{- end}}
@@ -38,9 +37,6 @@ func main() {
 				{{- if .ConfResolver.DefaultURIScheme }}
 				DefaultScheme: "{{ .ConfResolver.DefaultURIScheme }}",
 				{{- end }}
-				ConverterFactories: []confmap.ConverterFactory{
-					expandconverter.NewFactory(),
-				},
 			},
 		},
 		{{- end}}
diff --git a/cmd/otelcorecol/go.mod b/cmd/otelcorecol/go.mod
index ba5d483d339..d175223af25 100644
--- a/cmd/otelcorecol/go.mod
+++ b/cmd/otelcorecol/go.mod
@@ -9,7 +9,6 @@ toolchain go1.21.11
 require (
 	go.opentelemetry.io/collector/component v0.104.0
 	go.opentelemetry.io/collector/confmap v0.104.0
-	go.opentelemetry.io/collector/confmap/converter/expandconverter v0.104.0
 	go.opentelemetry.io/collector/confmap/provider/envprovider v0.104.0
 	go.opentelemetry.io/collector/confmap/provider/fileprovider v0.104.0
 	go.opentelemetry.io/collector/confmap/provider/httpprovider v0.104.0
diff --git a/cmd/otelcorecol/main.go b/cmd/otelcorecol/main.go
index 45b25c6bb27..be9d3ae0478 100644
--- a/cmd/otelcorecol/main.go
+++ b/cmd/otelcorecol/main.go
@@ -8,7 +8,6 @@ import (
 
 	"go.opentelemetry.io/collector/component"
 	"go.opentelemetry.io/collector/confmap"
-	"go.opentelemetry.io/collector/confmap/converter/expandconverter"
 	envprovider "go.opentelemetry.io/collector/confmap/provider/envprovider"
 	fileprovider "go.opentelemetry.io/collector/confmap/provider/fileprovider"
 	httpprovider "go.opentelemetry.io/collector/confmap/provider/httpprovider"
@@ -36,9 +35,6 @@ func main() {
 					httpsprovider.NewFactory(),
 					yamlprovider.NewFactory(),
 				},
-				ConverterFactories: []confmap.ConverterFactory{
-					expandconverter.NewFactory(),
-				},
 			},
 		},
 	}
diff --git a/confmap/converter/expandconverter/expand.go b/confmap/converter/expandconverter/expand.go
index aa18d1a3817..1f076882bac 100644
--- a/confmap/converter/expandconverter/expand.go
+++ b/confmap/converter/expandconverter/expand.go
@@ -25,6 +25,8 @@ type converter struct {
 
 // NewFactory returns a factory for a  confmap.Converter,
 // which expands all environment variables for a given confmap.Conf.
+//
+// Deprecated: [v0.105.0] BASH-style env var expansion is deprecated. Use `${FOO}` or `${env:FOO}` instead.
 func NewFactory() confmap.ConverterFactory {
 	return confmap.NewConverterFactory(newConverter)
 }
@@ -36,6 +38,7 @@ func newConverter(set confmap.ConverterSettings) confmap.Converter {
 	}
 }
 
+// Deprecated: [v0.105.0] BASH-style env var expansion is deprecated. Use `${FOO}` or `${env:FOO}` instead.
 func (c converter) Convert(_ context.Context, conf *confmap.Conf) error {
 	var err error
 	out := make(map[string]any)
diff --git a/confmap/converter/expandconverter/go.mod b/confmap/converter/expandconverter/go.mod
index f0d150834bb..9ae6f96e8cd 100644
--- a/confmap/converter/expandconverter/go.mod
+++ b/confmap/converter/expandconverter/go.mod
@@ -1,3 +1,4 @@
+// Deprecated: [v0.105.0] BASH-style env var expansion is deprecated. Use `${FOO}` or `${env:FOO}` instead.
 module go.opentelemetry.io/collector/confmap/converter/expandconverter
 
 go 1.21.0
diff --git a/otelcol/otelcoltest/config.go b/otelcol/otelcoltest/config.go
index cbc0be024f4..4ae0d6fe539 100644
--- a/otelcol/otelcoltest/config.go
+++ b/otelcol/otelcoltest/config.go
@@ -7,7 +7,6 @@ import (
 	"context"
 
 	"go.opentelemetry.io/collector/confmap"
-	"go.opentelemetry.io/collector/confmap/converter/expandconverter"
 	"go.opentelemetry.io/collector/confmap/provider/envprovider"
 	"go.opentelemetry.io/collector/confmap/provider/fileprovider"
 	"go.opentelemetry.io/collector/confmap/provider/httpprovider"
@@ -38,7 +37,6 @@ func LoadConfig(fileName string, factories otelcol.Factories) (*otelcol.Config,
 				yamlprovider.NewFactory(),
 				httpprovider.NewFactory(),
 			},
-			ConverterFactories: []confmap.ConverterFactory{expandconverter.NewFactory()},
 		},
 	})
 	if err != nil {

From 8dd2dcacbba869e5635720de80baa0307b852194 Mon Sep 17 00:00:00 2001
From: Tyler Helmuth <12352919+TylerHelmuth@users.noreply.github.com>
Date: Tue, 2 Jul 2024 10:11:26 -0600
Subject: [PATCH 02/13] add changelogs

---
 .chloggen/deprecate-expandconverter-2.yaml | 25 ++++++++++++++++++++++
 .chloggen/deprecate-expandconverter-3.yaml | 25 ++++++++++++++++++++++
 .chloggen/deprecate-expandconverter.yaml   | 25 ++++++++++++++++++++++
 3 files changed, 75 insertions(+)
 create mode 100644 .chloggen/deprecate-expandconverter-2.yaml
 create mode 100644 .chloggen/deprecate-expandconverter-3.yaml
 create mode 100644 .chloggen/deprecate-expandconverter.yaml

diff --git a/.chloggen/deprecate-expandconverter-2.yaml b/.chloggen/deprecate-expandconverter-2.yaml
new file mode 100644
index 00000000000..4375a388747
--- /dev/null
+++ b/.chloggen/deprecate-expandconverter-2.yaml
@@ -0,0 +1,25 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: breaking
+
+# The name of the component, or a single word describing the area of concern, (e.g. otlpreceiver)
+component: otelcoltest
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: The `otelcol.LoadConfig` method no longer sets the `expandconverter`.
+
+# One or more tracking issues or pull requests related to the change
+issues: [10510]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: [api]
diff --git a/.chloggen/deprecate-expandconverter-3.yaml b/.chloggen/deprecate-expandconverter-3.yaml
new file mode 100644
index 00000000000..ee8001aa4f3
--- /dev/null
+++ b/.chloggen/deprecate-expandconverter-3.yaml
@@ -0,0 +1,25 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: breaking
+
+# The name of the component, or a single word describing the area of concern, (e.g. otlpreceiver)
+component: ocb
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Collectors built with OCB will no longer include the `expandconverter`
+
+# One or more tracking issues or pull requests related to the change
+issues: [10510]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: [api]
diff --git a/.chloggen/deprecate-expandconverter.yaml b/.chloggen/deprecate-expandconverter.yaml
new file mode 100644
index 00000000000..770ce3e0164
--- /dev/null
+++ b/.chloggen/deprecate-expandconverter.yaml
@@ -0,0 +1,25 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: deprecation
+
+# The name of the component, or a single word describing the area of concern, (e.g. otlpreceiver)
+component: expandconverter
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Deprecate `expandconverter`.
+
+# One or more tracking issues or pull requests related to the change
+issues: [10510]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: [api]

From 7ec040794f6f52fbd768b0a746c09bea429e0c90 Mon Sep 17 00:00:00 2001
From: Tyler Helmuth <12352919+TylerHelmuth@users.noreply.github.com>
Date: Tue, 2 Jul 2024 13:05:18 -0600
Subject: [PATCH 03/13] Cleanup builder

---
 cmd/builder/README.md                              | 2 --
 cmd/builder/internal/builder/main_test.go          | 1 -
 cmd/builder/internal/builder/templates/go.mod.tmpl | 1 -
 cmd/builder/test/core.builder.yaml                 | 1 -
 otelcol/otelcoltest/go.mod                         | 1 -
 5 files changed, 6 deletions(-)

diff --git a/cmd/builder/README.md b/cmd/builder/README.md
index ec8d18c3808..003a7e93f6b 100644
--- a/cmd/builder/README.md
+++ b/cmd/builder/README.md
@@ -24,8 +24,6 @@ processors:
 providers:
   - gomod: go.opentelemetry.io/collector/confmap/provider/fileprovider v0.99.0
 
-converters:
-  - gomod: go.opentelemetry.io/collector/confmap/converter/expandconverter v0.99.0
 EOF
 $ builder --config=otelcol-builder.yaml
 $ cat > /tmp/otelcol.yaml <<EOF
diff --git a/cmd/builder/internal/builder/main_test.go b/cmd/builder/internal/builder/main_test.go
index 91c70f9845f..54c7cf3b10a 100644
--- a/cmd/builder/internal/builder/main_test.go
+++ b/cmd/builder/internal/builder/main_test.go
@@ -52,7 +52,6 @@ var (
 		"/config/configtls",
 		"/config/internal",
 		"/confmap",
-		"/confmap/converter/expandconverter",
 		"/confmap/provider/envprovider",
 		"/confmap/provider/fileprovider",
 		"/confmap/provider/httpprovider",
diff --git a/cmd/builder/internal/builder/templates/go.mod.tmpl b/cmd/builder/internal/builder/templates/go.mod.tmpl
index ad6fd3f78f6..3ce0e7eb454 100644
--- a/cmd/builder/internal/builder/templates/go.mod.tmpl
+++ b/cmd/builder/internal/builder/templates/go.mod.tmpl
@@ -6,7 +6,6 @@ go 1.21
 
 require (
 	{{if .Distribution.SupportsConfmapFactories -}}
-	go.opentelemetry.io/collector/confmap/converter/expandconverter v{{.Distribution.OtelColVersion}}
 	{{- range .Providers}}
 	{{if .GoMod}}{{.GoMod}}{{end}}
 	{{- end}}
diff --git a/cmd/builder/test/core.builder.yaml b/cmd/builder/test/core.builder.yaml
index 260429422c1..a284f92e52d 100644
--- a/cmd/builder/test/core.builder.yaml
+++ b/cmd/builder/test/core.builder.yaml
@@ -31,7 +31,6 @@ replaces:
   - go.opentelemetry.io/collector/config/configtls => ${WORKSPACE_DIR}/config/configtls
   - go.opentelemetry.io/collector/config/internal => ${WORKSPACE_DIR}/config/internal
   - go.opentelemetry.io/collector/confmap => ${WORKSPACE_DIR}/confmap
-  - go.opentelemetry.io/collector/confmap/converter/expandconverter => ${WORKSPACE_DIR}/confmap/converter/expandconverter
   - go.opentelemetry.io/collector/confmap/provider/envprovider => ${WORKSPACE_DIR}/confmap/provider/envprovider
   - go.opentelemetry.io/collector/confmap/provider/fileprovider => ${WORKSPACE_DIR}/confmap/provider/fileprovider
   - go.opentelemetry.io/collector/confmap/provider/httpprovider => ${WORKSPACE_DIR}/confmap/provider/httpprovider
diff --git a/otelcol/otelcoltest/go.mod b/otelcol/otelcoltest/go.mod
index 0259adae125..efb53c6a09d 100644
--- a/otelcol/otelcoltest/go.mod
+++ b/otelcol/otelcoltest/go.mod
@@ -6,7 +6,6 @@ require (
 	github.com/stretchr/testify v1.9.0
 	go.opentelemetry.io/collector/component v0.104.0
 	go.opentelemetry.io/collector/confmap v0.104.0
-	go.opentelemetry.io/collector/confmap/converter/expandconverter v0.104.0
 	go.opentelemetry.io/collector/confmap/provider/envprovider v0.104.0
 	go.opentelemetry.io/collector/confmap/provider/fileprovider v0.104.0
 	go.opentelemetry.io/collector/confmap/provider/httpprovider v0.104.0

From 3bbd4682eb58636659b11d93e08fddca59bb9267 Mon Sep 17 00:00:00 2001
From: Tyler Helmuth <12352919+TylerHelmuth@users.noreply.github.com>
Date: Tue, 2 Jul 2024 13:09:27 -0600
Subject: [PATCH 04/13] make crosslink

---
 cmd/otelcorecol/builder-config.yaml | 1 -
 cmd/otelcorecol/go.mod              | 2 --
 otelcol/otelcoltest/go.mod          | 2 --
 3 files changed, 5 deletions(-)

diff --git a/cmd/otelcorecol/builder-config.yaml b/cmd/otelcorecol/builder-config.yaml
index be9be01815d..61d9e949b45 100644
--- a/cmd/otelcorecol/builder-config.yaml
+++ b/cmd/otelcorecol/builder-config.yaml
@@ -54,7 +54,6 @@ replaces:
   - go.opentelemetry.io/collector/config/configtls => ../../config/configtls
   - go.opentelemetry.io/collector/config/internal => ../../config/internal
   - go.opentelemetry.io/collector/confmap => ../../confmap
-  - go.opentelemetry.io/collector/confmap/converter/expandconverter => ../../confmap/converter/expandconverter
   - go.opentelemetry.io/collector/confmap/provider/envprovider => ../../confmap/provider/envprovider
   - go.opentelemetry.io/collector/confmap/provider/fileprovider => ../../confmap/provider/fileprovider
   - go.opentelemetry.io/collector/confmap/provider/httpprovider => ../../confmap/provider/httpprovider
diff --git a/cmd/otelcorecol/go.mod b/cmd/otelcorecol/go.mod
index d175223af25..1896c79289e 100644
--- a/cmd/otelcorecol/go.mod
+++ b/cmd/otelcorecol/go.mod
@@ -157,8 +157,6 @@ replace go.opentelemetry.io/collector/config/internal => ../../config/internal
 
 replace go.opentelemetry.io/collector/confmap => ../../confmap
 
-replace go.opentelemetry.io/collector/confmap/converter/expandconverter => ../../confmap/converter/expandconverter
-
 replace go.opentelemetry.io/collector/confmap/provider/envprovider => ../../confmap/provider/envprovider
 
 replace go.opentelemetry.io/collector/confmap/provider/fileprovider => ../../confmap/provider/fileprovider
diff --git a/otelcol/otelcoltest/go.mod b/otelcol/otelcoltest/go.mod
index efb53c6a09d..2f000fd2a81 100644
--- a/otelcol/otelcoltest/go.mod
+++ b/otelcol/otelcoltest/go.mod
@@ -114,8 +114,6 @@ replace go.opentelemetry.io/collector/otelcol => ../
 
 replace go.opentelemetry.io/collector/confmap/provider/yamlprovider => ../../confmap/provider/yamlprovider
 
-replace go.opentelemetry.io/collector/confmap/converter/expandconverter => ../../confmap/converter/expandconverter
-
 replace go.opentelemetry.io/collector => ../..
 
 replace go.opentelemetry.io/collector/service => ../../service

From a8a451cec229e9b1cceb5eaa8068321a4cce8e6a Mon Sep 17 00:00:00 2001
From: Tyler Helmuth <12352919+TylerHelmuth@users.noreply.github.com>
Date: Thu, 1 Aug 2024 15:47:59 -0600
Subject: [PATCH 05/13] Delete tests

---
 .../converter/expandconverter/expand_test.go  | 367 ------------------
 1 file changed, 367 deletions(-)
 delete mode 100644 confmap/converter/expandconverter/expand_test.go

diff --git a/confmap/converter/expandconverter/expand_test.go b/confmap/converter/expandconverter/expand_test.go
deleted file mode 100644
index 4c7ff254e15..00000000000
--- a/confmap/converter/expandconverter/expand_test.go
+++ /dev/null
@@ -1,367 +0,0 @@
-// Copyright The OpenTelemetry Authors
-// SPDX-License-Identifier: Apache-2.0
-
-package expandconverter
-
-import (
-	"context"
-	"fmt"
-	"path/filepath"
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-	"go.uber.org/zap"
-	"go.uber.org/zap/zapcore"
-	"go.uber.org/zap/zaptest/observer"
-
-	"go.opentelemetry.io/collector/confmap"
-	"go.opentelemetry.io/collector/confmap/confmaptest"
-	"go.opentelemetry.io/collector/confmap/internal/envvar"
-	"go.opentelemetry.io/collector/featuregate"
-	"go.opentelemetry.io/collector/internal/globalgates"
-)
-
-func TestNewExpandConverter(t *testing.T) {
-	var testCases = []struct {
-		name string // test case name (also file name containing config yaml)
-	}{
-		{name: "expand-with-no-env.yaml"},
-		{name: "expand-with-partial-env.yaml"},
-		{name: "expand-with-all-env.yaml"},
-	}
-
-	const valueExtra = "some string"
-	const valueExtraMapValue = "some map value"
-	const valueExtraListMapValue = "some list map value"
-	const valueExtraListElement = "some list value"
-	t.Setenv("EXTRA", valueExtra)
-	t.Setenv("EXTRA_MAP_VALUE_1", valueExtraMapValue+"_1")
-	t.Setenv("EXTRA_MAP_VALUE_2", valueExtraMapValue+"_2")
-	t.Setenv("EXTRA_LIST_MAP_VALUE_1", valueExtraListMapValue+"_1")
-	t.Setenv("EXTRA_LIST_MAP_VALUE_2", valueExtraListMapValue+"_2")
-	t.Setenv("EXTRA_LIST_VALUE_1", valueExtraListElement+"_1")
-	t.Setenv("EXTRA_LIST_VALUE_2", valueExtraListElement+"_2")
-
-	expectedCfgMap, errExpected := confmaptest.LoadConf(filepath.Join("testdata", "expand-with-no-env.yaml"))
-	require.NoError(t, errExpected, "Unable to get expected config")
-
-	for _, test := range testCases {
-		t.Run(test.name, func(t *testing.T) {
-			require.NoError(t, featuregate.GlobalRegistry().Set(globalgates.UseUnifiedEnvVarExpansionRules.ID(), false))
-			t.Cleanup(func() {
-				require.NoError(t, featuregate.GlobalRegistry().Set(globalgates.UseUnifiedEnvVarExpansionRules.ID(), true))
-			})
-
-			conf, err := confmaptest.LoadConf(filepath.Join("testdata", test.name))
-			require.NoError(t, err, "Unable to get config")
-
-			// Test that expanded configs are the same with the simple config with no env vars.
-			require.NoError(t, createConverter().Convert(context.Background(), conf))
-			assert.Equal(t, expectedCfgMap.ToStringMap(), conf.ToStringMap())
-		})
-	}
-}
-
-func TestNewExpandConverter_UseUnifiedEnvVarExpansionRules(t *testing.T) {
-	require.NoError(t, featuregate.GlobalRegistry().Set(globalgates.UseUnifiedEnvVarExpansionRules.ID(), true))
-	t.Cleanup(func() {
-		require.NoError(t, featuregate.GlobalRegistry().Set(globalgates.UseUnifiedEnvVarExpansionRules.ID(), false))
-	})
-
-	const valueExtra = "some string"
-	const valueExtraMapValue = "some map value"
-	const valueExtraListMapValue = "some list map value"
-	const valueExtraListElement = "some list value"
-	t.Setenv("EXTRA", valueExtra)
-	t.Setenv("EXTRA_MAP_VALUE_1", valueExtraMapValue+"_1")
-	t.Setenv("EXTRA_MAP_VALUE_2", valueExtraMapValue+"_2")
-	t.Setenv("EXTRA_LIST_MAP_VALUE_1", valueExtraListMapValue+"_1")
-	t.Setenv("EXTRA_LIST_MAP_VALUE_2", valueExtraListMapValue+"_2")
-	t.Setenv("EXTRA_LIST_VALUE_1", valueExtraListElement+"_1")
-	t.Setenv("EXTRA_LIST_VALUE_2", valueExtraListElement+"_2")
-
-	conf, err := confmaptest.LoadConf(filepath.Join("testdata", "expand-with-all-env.yaml"))
-	require.NoError(t, err, "Unable to get config")
-
-	// Test that expanded configs are the same with the simple config with no env vars.
-	require.ErrorContains(t, createConverter().Convert(context.Background(), conf), "variable substitution using $VAR has been deprecated in favor of ${VAR} and ${env:VAR}")
-}
-
-func TestNewExpandConverter_EscapedMaps(t *testing.T) {
-	const receiverExtraMapValue = "some map value"
-	t.Setenv("MAP_VALUE", receiverExtraMapValue)
-
-	conf := confmap.NewFromStringMap(
-		map[string]any{
-			"test_string_map": map[string]any{
-				"recv": "$MAP_VALUE",
-			},
-			"test_interface_map": map[any]any{
-				"recv": "$MAP_VALUE",
-			}},
-	)
-	require.NoError(t, createConverter().Convert(context.Background(), conf))
-
-	expectedMap := map[string]any{
-		"test_string_map": map[string]any{
-			"recv": receiverExtraMapValue,
-		},
-		"test_interface_map": map[string]any{
-			"recv": receiverExtraMapValue,
-		}}
-	assert.Equal(t, expectedMap, conf.ToStringMap())
-}
-
-func TestNewExpandConverter_EscapedEnvVars(t *testing.T) {
-	const receiverExtraMapValue = "some map value"
-	t.Setenv("MAP_VALUE_2", receiverExtraMapValue)
-
-	// Retrieve the config
-	conf, err := confmaptest.LoadConf(filepath.Join("testdata", "expand-escaped-env.yaml"))
-	require.NoError(t, err, "Unable to get config")
-
-	expectedMap := map[string]any{
-		"test_map": map[string]any{
-			// $$ -> escaped $
-			"recv.1": "$MAP_VALUE_1",
-			// $$$ -> escaped $ + substituted env var
-			"recv.2": "$" + receiverExtraMapValue,
-			// $$$$ -> two escaped $
-			"recv.3": "$$MAP_VALUE_3",
-			// escaped $ in the middle
-			"recv.4": "some${MAP_VALUE_4}text",
-			// $$$$ -> two escaped $
-			"recv.5": "${ONE}${TWO}",
-			// trailing escaped $
-			"recv.6": "text$",
-			// escaped $ alone
-			"recv.7": "$",
-		}}
-	require.NoError(t, createConverter().Convert(context.Background(), conf))
-	assert.Equal(t, expectedMap, conf.ToStringMap())
-}
-
-func TestNewExpandConverterHostPort(t *testing.T) {
-	t.Setenv("HOST", "127.0.0.1")
-	t.Setenv("PORT", "4317")
-
-	var testCases = []struct {
-		name     string
-		input    map[string]any
-		expected map[string]any
-	}{
-		{
-			name: "brackets",
-			input: map[string]any{
-				"test": "${HOST}:${PORT}",
-			},
-			expected: map[string]any{
-				"test": "127.0.0.1:4317",
-			},
-		},
-		{
-			name: "no brackets",
-			input: map[string]any{
-				"test": "$HOST:$PORT",
-			},
-			expected: map[string]any{
-				"test": "127.0.0.1:4317",
-			},
-		},
-		{
-			name: "mix",
-			input: map[string]any{
-				"test": "${HOST}:$PORT",
-			},
-			expected: map[string]any{
-				"test": "127.0.0.1:4317",
-			},
-		},
-		{
-			name: "reverse mix",
-			input: map[string]any{
-				"test": "$HOST:${PORT}",
-			},
-			expected: map[string]any{
-				"test": "127.0.0.1:4317",
-			},
-		},
-	}
-	for _, tt := range testCases {
-		t.Run(tt.name, func(t *testing.T) {
-			conf := confmap.NewFromStringMap(tt.input)
-			require.NoError(t, createConverter().Convert(context.Background(), conf))
-			assert.Equal(t, tt.expected, conf.ToStringMap())
-		})
-	}
-}
-
-func NewTestConverter() (confmap.Converter, *observer.ObservedLogs) {
-	core, logs := observer.New(zapcore.InfoLevel)
-	conv := converter{loggedDeprecations: make(map[string]struct{}), logger: zap.New(core)}
-	return conv, logs
-}
-
-func TestDeprecatedWarning(t *testing.T) {
-	msgTemplate := `Variable substitution using $VAR will be deprecated in favor of ${VAR} and ${env:VAR}, please update $%s`
-	t.Setenv("HOST", "127.0.0.1")
-	t.Setenv("PORT", "4317")
-
-	t.Setenv("HOST_NAME", "127.0.0.2")
-	t.Setenv("HOSTNAME", "127.0.0.3")
-
-	t.Setenv("BAD!HOST", "127.0.0.2")
-
-	var testCases = []struct {
-		name             string
-		input            map[string]any
-		expectedOutput   map[string]any
-		expectedWarnings []string
-		expectedError    error
-	}{
-		{
-			name: "no warning",
-			input: map[string]any{
-				"test": "${HOST}:${PORT}",
-			},
-			expectedOutput: map[string]any{
-				"test": "127.0.0.1:4317",
-			},
-			expectedWarnings: []string{},
-			expectedError:    nil,
-		},
-		{
-			name: "one deprecated var",
-			input: map[string]any{
-				"test": "${HOST}:$PORT",
-			},
-			expectedOutput: map[string]any{
-				"test": "127.0.0.1:4317",
-			},
-			expectedWarnings: []string{"PORT"},
-			expectedError:    nil,
-		},
-		{
-			name: "two deprecated vars",
-			input: map[string]any{
-				"test": "$HOST:$PORT",
-			},
-			expectedOutput: map[string]any{
-				"test": "127.0.0.1:4317",
-			},
-			expectedWarnings: []string{"HOST", "PORT"},
-			expectedError:    nil,
-		},
-		{
-			name: "one depracated serveral times",
-			input: map[string]any{
-				"test":  "$HOST,$HOST",
-				"test2": "$HOST",
-			},
-			expectedOutput: map[string]any{
-				"test":  "127.0.0.1,127.0.0.1",
-				"test2": "127.0.0.1",
-			},
-			expectedWarnings: []string{"HOST"},
-			expectedError:    nil,
-		},
-		{
-			name: "one warning",
-			input: map[string]any{
-				"test": "$HOST_NAME,${HOSTNAME}",
-			},
-			expectedOutput: map[string]any{
-				"test": "127.0.0.2,127.0.0.3",
-			},
-			expectedWarnings: []string{"HOST_NAME"},
-			expectedError:    nil,
-		},
-		{
-			name: "malformed environment variable",
-			input: map[string]any{
-				"test": "${BAD!HOST}",
-			},
-			expectedOutput: map[string]any{
-				"test": "blah",
-			},
-			expectedWarnings: []string{},
-			expectedError:    fmt.Errorf("environment variable \"BAD!HOST\" has invalid name: must match regex %s", envvar.ValidationRegexp),
-		},
-		{
-			name: "malformed environment variable number",
-			input: map[string]any{
-				"test": "${2BADHOST}",
-			},
-			expectedOutput: map[string]any{
-				"test": "blah",
-			},
-			expectedWarnings: []string{},
-			expectedError:    fmt.Errorf("environment variable \"2BADHOST\" has invalid name: must match regex %s", envvar.ValidationRegexp),
-		},
-		{
-			name: "malformed environment variable unicode",
-			input: map[string]any{
-				"test": "${😊BADHOST}",
-			},
-			expectedOutput: map[string]any{
-				"test": "blah",
-			},
-			expectedWarnings: []string{},
-			expectedError:    fmt.Errorf("environment variable \"😊BADHOST\" has invalid name: must match regex %s", envvar.ValidationRegexp),
-		},
-	}
-
-	for _, tt := range testCases {
-		t.Run(tt.name, func(t *testing.T) {
-			conf := confmap.NewFromStringMap(tt.input)
-			conv, logs := NewTestConverter()
-			err := conv.Convert(context.Background(), conf)
-			assert.Equal(t, tt.expectedError, err)
-			if tt.expectedError == nil {
-				assert.Equal(t, tt.expectedOutput, conf.ToStringMap())
-			}
-			assert.Equal(t, len(tt.expectedWarnings), len(logs.All()))
-			for i, variable := range tt.expectedWarnings {
-				errorMsg := fmt.Sprintf(msgTemplate, variable)
-				assert.Equal(t, errorMsg, logs.All()[i].Message)
-			}
-		})
-	}
-}
-
-func TestNewExpandConverterWithErrors(t *testing.T) {
-	var testCases = []struct {
-		name          string // test case name (also file name containing config yaml)
-		expectedError error
-	}{
-		{
-			name:          "expand-list-error.yaml",
-			expectedError: fmt.Errorf("environment variable \"EXTRA_LIST_^VALUE_2\" has invalid name: must match regex %s", envvar.ValidationRegexp),
-		},
-		{
-			name:          "expand-list-map-error.yaml",
-			expectedError: fmt.Errorf("environment variable \"EXTRA_LIST_MAP_V#ALUE_2\" has invalid name: must match regex %s", envvar.ValidationRegexp),
-		},
-		{
-			name:          "expand-map-error.yaml",
-			expectedError: fmt.Errorf("environment variable \"EX#TRA\" has invalid name: must match regex %s", envvar.ValidationRegexp),
-		},
-	}
-
-	for _, test := range testCases {
-		t.Run(test.name, func(t *testing.T) {
-			conf, err := confmaptest.LoadConf(filepath.Join("testdata", "errors", test.name))
-			require.NoError(t, err, "Unable to get config")
-
-			// Test that expanded configs are the same with the simple config with no env vars.
-			err = createConverter().Convert(context.Background(), conf)
-
-			assert.Equal(t, test.expectedError, err)
-		})
-	}
-}
-
-func createConverter() confmap.Converter {
-	return NewFactory().Create(confmap.ConverterSettings{Logger: zap.NewNop()})
-}

From 2f90729ea832d738da47325c4fac8ba8e04f2c37 Mon Sep 17 00:00:00 2001
From: Tyler Helmuth <12352919+TylerHelmuth@users.noreply.github.com>
Date: Thu, 1 Aug 2024 15:48:26 -0600
Subject: [PATCH 06/13] make gotidy

---
 confmap/converter/expandconverter/go.mod | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/confmap/converter/expandconverter/go.mod b/confmap/converter/expandconverter/go.mod
index 20c6db4680e..9eff499a8e7 100644
--- a/confmap/converter/expandconverter/go.mod
+++ b/confmap/converter/expandconverter/go.mod
@@ -4,16 +4,13 @@ module go.opentelemetry.io/collector/confmap/converter/expandconverter
 go 1.21.0
 
 require (
-	github.com/stretchr/testify v1.9.0
 	go.opentelemetry.io/collector/confmap v0.106.1
-	go.opentelemetry.io/collector/featuregate v1.12.0
 	go.opentelemetry.io/collector/internal/globalgates v0.106.1
 	go.uber.org/goleak v1.3.0
 	go.uber.org/zap v1.27.0
 )
 
 require (
-	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/go-viper/mapstructure/v2 v2.0.0 // indirect
 	github.com/hashicorp/go-version v1.7.0 // indirect
 	github.com/knadh/koanf/maps v0.1.1 // indirect
@@ -21,7 +18,7 @@ require (
 	github.com/knadh/koanf/v2 v2.1.1 // indirect
 	github.com/mitchellh/copystructure v1.2.0 // indirect
 	github.com/mitchellh/reflectwalk v1.0.2 // indirect
-	github.com/pmezard/go-difflib v1.0.0 // indirect
+	go.opentelemetry.io/collector/featuregate v1.12.0 // indirect
 	go.uber.org/multierr v1.11.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

From 787a7a795f52be4960aa0f9dd7503e2e32f95b18 Mon Sep 17 00:00:00 2001
From: Tyler Helmuth <12352919+TylerHelmuth@users.noreply.github.com>
Date: Thu, 1 Aug 2024 15:55:52 -0600
Subject: [PATCH 07/13] nolint since these tests are fix in the other pr

---
 confmap/internal/e2e/expand_test.go | 1 +
 1 file changed, 1 insertion(+)

diff --git a/confmap/internal/e2e/expand_test.go b/confmap/internal/e2e/expand_test.go
index 018725d30d5..a0eb3349ca7 100644
--- a/confmap/internal/e2e/expand_test.go
+++ b/confmap/internal/e2e/expand_test.go
@@ -20,6 +20,7 @@ import (
 )
 
 // Test_EscapedEnvVars tests that the resolver supports escaped env vars working together with expand converter.
+// nolint
 func Test_EscapedEnvVars(t *testing.T) {
 	tests := []struct {
 		name   string

From 2614da9a03f8bff791a3c201f2e91835b628a09e Mon Sep 17 00:00:00 2001
From: Tyler Helmuth <12352919+TylerHelmuth@users.noreply.github.com>
Date: Wed, 7 Aug 2024 11:47:57 -0600
Subject: [PATCH 08/13] Apply suggestions from code review

Co-authored-by: Alex Boten <223565+codeboten@users.noreply.github.com>
---
 confmap/converter/expandconverter/expand.go | 4 ++--
 confmap/converter/expandconverter/go.mod    | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/confmap/converter/expandconverter/expand.go b/confmap/converter/expandconverter/expand.go
index a04efbc6e54..263c5fc7eeb 100644
--- a/confmap/converter/expandconverter/expand.go
+++ b/confmap/converter/expandconverter/expand.go
@@ -26,7 +26,7 @@ type converter struct {
 // NewFactory returns a factory for a  confmap.Converter,
 // which expands all environment variables for a given confmap.Conf.
 //
-// Deprecated: [v0.105.0] BASH-style env var expansion is deprecated. Use `${FOO}` or `${env:FOO}` instead.
+// Deprecated: [v0.107.0] BASH-style env var expansion is deprecated. Use `${FOO}` or `${env:FOO}` instead.
 func NewFactory() confmap.ConverterFactory {
 	return confmap.NewConverterFactory(newConverter)
 }
@@ -38,7 +38,7 @@ func newConverter(set confmap.ConverterSettings) confmap.Converter {
 	}
 }
 
-// Deprecated: [v0.105.0] BASH-style env var expansion is deprecated. Use `${FOO}` or `${env:FOO}` instead.
+// Deprecated: [v0.107.0] BASH-style env var expansion is deprecated. Use `${FOO}` or `${env:FOO}` instead.
 func (c converter) Convert(_ context.Context, conf *confmap.Conf) error {
 	var err error
 	out := make(map[string]any)
diff --git a/confmap/converter/expandconverter/go.mod b/confmap/converter/expandconverter/go.mod
index 9eff499a8e7..d125d7dc0e3 100644
--- a/confmap/converter/expandconverter/go.mod
+++ b/confmap/converter/expandconverter/go.mod
@@ -1,4 +1,4 @@
-// Deprecated: [v0.105.0] BASH-style env var expansion is deprecated. Use `${FOO}` or `${env:FOO}` instead.
+// Deprecated: [v0.107.0] BASH-style env var expansion is deprecated. Use `${FOO}` or `${env:FOO}` instead.
 module go.opentelemetry.io/collector/confmap/converter/expandconverter
 
 go 1.21.0

From e900c844c893690e424d1e71ebf423312b6486cb Mon Sep 17 00:00:00 2001
From: Tyler Helmuth <12352919+TylerHelmuth@users.noreply.github.com>
Date: Wed, 7 Aug 2024 12:07:25 -0600
Subject: [PATCH 09/13] Add back tests, remove feature gate usage

---
 confmap/converter/expandconverter/expand.go   |  15 -
 .../converter/expandconverter/expand_test.go  | 290 ++++++++++++++++++
 confmap/converter/expandconverter/go.mod      |   5 +-
 3 files changed, 294 insertions(+), 16 deletions(-)
 create mode 100644 confmap/converter/expandconverter/expand_test.go

diff --git a/confmap/converter/expandconverter/expand.go b/confmap/converter/expandconverter/expand.go
index a04efbc6e54..a7d4e9726b7 100644
--- a/confmap/converter/expandconverter/expand.go
+++ b/confmap/converter/expandconverter/expand.go
@@ -7,13 +7,11 @@ import (
 	"context"
 	"fmt"
 	"os"
-	"regexp"
 
 	"go.uber.org/zap"
 
 	"go.opentelemetry.io/collector/confmap"
 	"go.opentelemetry.io/collector/confmap/internal/envvar"
-	"go.opentelemetry.io/collector/internal/globalgates"
 )
 
 type converter struct {
@@ -93,19 +91,6 @@ func (c converter) expandEnv(s string) (string, error) {
 			return "$"
 		}
 
-		// Matches on $VAR style environment variables
-		// in order to make sure we don't log a warning for ${VAR}
-		var regex = regexp.MustCompile(fmt.Sprintf(`\$%s`, regexp.QuoteMeta(str)))
-		if _, exists := c.loggedDeprecations[str]; !exists && regex.MatchString(s) {
-			if globalgates.UseUnifiedEnvVarExpansionRules.IsEnabled() {
-				err = fmt.Errorf("variable substitution using $VAR has been deprecated in favor of ${VAR} and ${env:VAR} - please update $%s or temporarily disable the confmap.unifyEnvVarExpansion feature gate", str)
-				return ""
-			}
-			msg := fmt.Sprintf("Variable substitution using $VAR will be deprecated in favor of ${VAR} and ${env:VAR}, please update $%s", str)
-			c.logger.Warn(msg, zap.String("variable", str))
-			c.loggedDeprecations[str] = struct{}{}
-		}
-
 		// For $ENV style environment variables os.Expand returns once it hits a character that isn't an underscore or
 		// an alphanumeric character - so we cannot detect those malformed environment variables.
 		// For ${ENV} style variables we can detect those kinds of env var names!
diff --git a/confmap/converter/expandconverter/expand_test.go b/confmap/converter/expandconverter/expand_test.go
new file mode 100644
index 00000000000..4934bb5a008
--- /dev/null
+++ b/confmap/converter/expandconverter/expand_test.go
@@ -0,0 +1,290 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package expandconverter
+
+import (
+	"context"
+	"fmt"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
+	"go.uber.org/zap/zaptest/observer"
+
+	"go.opentelemetry.io/collector/confmap"
+	"go.opentelemetry.io/collector/confmap/confmaptest"
+	"go.opentelemetry.io/collector/confmap/internal/envvar"
+)
+
+func TestNewExpandConverter(t *testing.T) {
+	var testCases = []struct {
+		name string // test case name (also file name containing config yaml)
+	}{
+		{name: "expand-with-no-env.yaml"},
+		{name: "expand-with-partial-env.yaml"},
+		{name: "expand-with-all-env.yaml"},
+	}
+
+	const valueExtra = "some string"
+	const valueExtraMapValue = "some map value"
+	const valueExtraListMapValue = "some list map value"
+	const valueExtraListElement = "some list value"
+	t.Setenv("EXTRA", valueExtra)
+	t.Setenv("EXTRA_MAP_VALUE_1", valueExtraMapValue+"_1")
+	t.Setenv("EXTRA_MAP_VALUE_2", valueExtraMapValue+"_2")
+	t.Setenv("EXTRA_LIST_MAP_VALUE_1", valueExtraListMapValue+"_1")
+	t.Setenv("EXTRA_LIST_MAP_VALUE_2", valueExtraListMapValue+"_2")
+	t.Setenv("EXTRA_LIST_VALUE_1", valueExtraListElement+"_1")
+	t.Setenv("EXTRA_LIST_VALUE_2", valueExtraListElement+"_2")
+
+	expectedCfgMap, errExpected := confmaptest.LoadConf(filepath.Join("testdata", "expand-with-no-env.yaml"))
+	require.NoError(t, errExpected, "Unable to get expected config")
+
+	for _, test := range testCases {
+		t.Run(test.name, func(t *testing.T) {
+			conf, err := confmaptest.LoadConf(filepath.Join("testdata", test.name))
+			require.NoError(t, err, "Unable to get config")
+
+			// Test that expanded configs are the same with the simple config with no env vars.
+			require.NoError(t, createConverter().Convert(context.Background(), conf))
+			assert.Equal(t, expectedCfgMap.ToStringMap(), conf.ToStringMap())
+		})
+	}
+}
+
+func TestNewExpandConverter_EscapedMaps(t *testing.T) {
+	const receiverExtraMapValue = "some map value"
+	t.Setenv("MAP_VALUE", receiverExtraMapValue)
+
+	conf := confmap.NewFromStringMap(
+		map[string]any{
+			"test_string_map": map[string]any{
+				"recv": "$MAP_VALUE",
+			},
+			"test_interface_map": map[any]any{
+				"recv": "$MAP_VALUE",
+			}},
+	)
+	require.NoError(t, createConverter().Convert(context.Background(), conf))
+
+	expectedMap := map[string]any{
+		"test_string_map": map[string]any{
+			"recv": receiverExtraMapValue,
+		},
+		"test_interface_map": map[string]any{
+			"recv": receiverExtraMapValue,
+		}}
+	assert.Equal(t, expectedMap, conf.ToStringMap())
+}
+
+func TestNewExpandConverter_EscapedEnvVars(t *testing.T) {
+	const receiverExtraMapValue = "some map value"
+	t.Setenv("MAP_VALUE_2", receiverExtraMapValue)
+
+	// Retrieve the config
+	conf, err := confmaptest.LoadConf(filepath.Join("testdata", "expand-escaped-env.yaml"))
+	require.NoError(t, err, "Unable to get config")
+
+	expectedMap := map[string]any{
+		"test_map": map[string]any{
+			// $$ -> escaped $
+			"recv.1": "$MAP_VALUE_1",
+			// $$$ -> escaped $ + substituted env var
+			"recv.2": "$" + receiverExtraMapValue,
+			// $$$$ -> two escaped $
+			"recv.3": "$$MAP_VALUE_3",
+			// escaped $ in the middle
+			"recv.4": "some${MAP_VALUE_4}text",
+			// $$$$ -> two escaped $
+			"recv.5": "${ONE}${TWO}",
+			// trailing escaped $
+			"recv.6": "text$",
+			// escaped $ alone
+			"recv.7": "$",
+		}}
+	require.NoError(t, createConverter().Convert(context.Background(), conf))
+	assert.Equal(t, expectedMap, conf.ToStringMap())
+}
+
+func TestNewExpandConverterHostPort(t *testing.T) {
+	t.Setenv("HOST", "127.0.0.1")
+	t.Setenv("PORT", "4317")
+
+	var testCases = []struct {
+		name     string
+		input    map[string]any
+		expected map[string]any
+	}{
+		{
+			name: "brackets",
+			input: map[string]any{
+				"test": "${HOST}:${PORT}",
+			},
+			expected: map[string]any{
+				"test": "127.0.0.1:4317",
+			},
+		},
+		{
+			name: "no brackets",
+			input: map[string]any{
+				"test": "$HOST:$PORT",
+			},
+			expected: map[string]any{
+				"test": "127.0.0.1:4317",
+			},
+		},
+		{
+			name: "mix",
+			input: map[string]any{
+				"test": "${HOST}:$PORT",
+			},
+			expected: map[string]any{
+				"test": "127.0.0.1:4317",
+			},
+		},
+		{
+			name: "reverse mix",
+			input: map[string]any{
+				"test": "$HOST:${PORT}",
+			},
+			expected: map[string]any{
+				"test": "127.0.0.1:4317",
+			},
+		},
+	}
+	for _, tt := range testCases {
+		t.Run(tt.name, func(t *testing.T) {
+			conf := confmap.NewFromStringMap(tt.input)
+			require.NoError(t, createConverter().Convert(context.Background(), conf))
+			assert.Equal(t, tt.expected, conf.ToStringMap())
+		})
+	}
+}
+
+func NewTestConverter() (confmap.Converter, *observer.ObservedLogs) {
+	core, logs := observer.New(zapcore.InfoLevel)
+	conv := converter{loggedDeprecations: make(map[string]struct{}), logger: zap.New(core)}
+	return conv, logs
+}
+
+func TestDeprecatedWarning(t *testing.T) {
+	msgTemplate := `Variable substitution using $VAR will be deprecated in favor of ${VAR} and ${env:VAR}, please update $%s`
+	t.Setenv("HOST", "127.0.0.1")
+	t.Setenv("PORT", "4317")
+
+	t.Setenv("HOST_NAME", "127.0.0.2")
+	t.Setenv("HOSTNAME", "127.0.0.3")
+
+	t.Setenv("BAD!HOST", "127.0.0.2")
+
+	var testCases = []struct {
+		name             string
+		input            map[string]any
+		expectedOutput   map[string]any
+		expectedWarnings []string
+		expectedError    error
+	}{
+		{
+			name: "no warning",
+			input: map[string]any{
+				"test": "${HOST}:${PORT}",
+			},
+			expectedOutput: map[string]any{
+				"test": "127.0.0.1:4317",
+			},
+			expectedWarnings: []string{},
+			expectedError:    nil,
+		},
+		{
+			name: "malformed environment variable",
+			input: map[string]any{
+				"test": "${BAD!HOST}",
+			},
+			expectedOutput: map[string]any{
+				"test": "blah",
+			},
+			expectedWarnings: []string{},
+			expectedError:    fmt.Errorf("environment variable \"BAD!HOST\" has invalid name: must match regex %s", envvar.ValidationRegexp),
+		},
+		{
+			name: "malformed environment variable number",
+			input: map[string]any{
+				"test": "${2BADHOST}",
+			},
+			expectedOutput: map[string]any{
+				"test": "blah",
+			},
+			expectedWarnings: []string{},
+			expectedError:    fmt.Errorf("environment variable \"2BADHOST\" has invalid name: must match regex %s", envvar.ValidationRegexp),
+		},
+		{
+			name: "malformed environment variable unicode",
+			input: map[string]any{
+				"test": "${😊BADHOST}",
+			},
+			expectedOutput: map[string]any{
+				"test": "blah",
+			},
+			expectedWarnings: []string{},
+			expectedError:    fmt.Errorf("environment variable \"😊BADHOST\" has invalid name: must match regex %s", envvar.ValidationRegexp),
+		},
+	}
+
+	for _, tt := range testCases {
+		t.Run(tt.name, func(t *testing.T) {
+			conf := confmap.NewFromStringMap(tt.input)
+			conv, logs := NewTestConverter()
+			err := conv.Convert(context.Background(), conf)
+			assert.Equal(t, tt.expectedError, err)
+			if tt.expectedError == nil {
+				assert.Equal(t, tt.expectedOutput, conf.ToStringMap())
+			}
+			assert.Equal(t, len(tt.expectedWarnings), len(logs.All()))
+			for i, variable := range tt.expectedWarnings {
+				errorMsg := fmt.Sprintf(msgTemplate, variable)
+				assert.Equal(t, errorMsg, logs.All()[i].Message)
+			}
+		})
+	}
+}
+
+func TestNewExpandConverterWithErrors(t *testing.T) {
+	var testCases = []struct {
+		name          string // test case name (also file name containing config yaml)
+		expectedError error
+	}{
+		{
+			name:          "expand-list-error.yaml",
+			expectedError: fmt.Errorf("environment variable \"EXTRA_LIST_^VALUE_2\" has invalid name: must match regex %s", envvar.ValidationRegexp),
+		},
+		{
+			name:          "expand-list-map-error.yaml",
+			expectedError: fmt.Errorf("environment variable \"EXTRA_LIST_MAP_V#ALUE_2\" has invalid name: must match regex %s", envvar.ValidationRegexp),
+		},
+		{
+			name:          "expand-map-error.yaml",
+			expectedError: fmt.Errorf("environment variable \"EX#TRA\" has invalid name: must match regex %s", envvar.ValidationRegexp),
+		},
+	}
+
+	for _, test := range testCases {
+		t.Run(test.name, func(t *testing.T) {
+			conf, err := confmaptest.LoadConf(filepath.Join("testdata", "errors", test.name))
+			require.NoError(t, err, "Unable to get config")
+
+			// Test that expanded configs are the same with the simple config with no env vars.
+			err = createConverter().Convert(context.Background(), conf)
+
+			assert.Equal(t, test.expectedError, err)
+		})
+	}
+}
+
+func createConverter() confmap.Converter {
+	// nolint
+	return NewFactory().Create(confmap.ConverterSettings{Logger: zap.NewNop()})
+}
diff --git a/confmap/converter/expandconverter/go.mod b/confmap/converter/expandconverter/go.mod
index 9eff499a8e7..20c6db4680e 100644
--- a/confmap/converter/expandconverter/go.mod
+++ b/confmap/converter/expandconverter/go.mod
@@ -4,13 +4,16 @@ module go.opentelemetry.io/collector/confmap/converter/expandconverter
 go 1.21.0
 
 require (
+	github.com/stretchr/testify v1.9.0
 	go.opentelemetry.io/collector/confmap v0.106.1
+	go.opentelemetry.io/collector/featuregate v1.12.0
 	go.opentelemetry.io/collector/internal/globalgates v0.106.1
 	go.uber.org/goleak v1.3.0
 	go.uber.org/zap v1.27.0
 )
 
 require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/go-viper/mapstructure/v2 v2.0.0 // indirect
 	github.com/hashicorp/go-version v1.7.0 // indirect
 	github.com/knadh/koanf/maps v0.1.1 // indirect
@@ -18,7 +21,7 @@ require (
 	github.com/knadh/koanf/v2 v2.1.1 // indirect
 	github.com/mitchellh/copystructure v1.2.0 // indirect
 	github.com/mitchellh/reflectwalk v1.0.2 // indirect
-	go.opentelemetry.io/collector/featuregate v1.12.0 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
 	go.uber.org/multierr v1.11.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

From 82452beb642d57684438458569584cfda1acda7b Mon Sep 17 00:00:00 2001
From: Tyler Helmuth <12352919+TylerHelmuth@users.noreply.github.com>
Date: Wed, 7 Aug 2024 12:09:51 -0600
Subject: [PATCH 10/13] make gotidy

---
 confmap/converter/expandconverter/go.mod | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/confmap/converter/expandconverter/go.mod b/confmap/converter/expandconverter/go.mod
index 575008f5a96..fc66216a4f4 100644
--- a/confmap/converter/expandconverter/go.mod
+++ b/confmap/converter/expandconverter/go.mod
@@ -6,8 +6,6 @@ go 1.21.0
 require (
 	github.com/stretchr/testify v1.9.0
 	go.opentelemetry.io/collector/confmap v0.106.1
-	go.opentelemetry.io/collector/featuregate v1.12.0
-	go.opentelemetry.io/collector/internal/globalgates v0.106.1
 	go.uber.org/goleak v1.3.0
 	go.uber.org/zap v1.27.0
 )
@@ -22,6 +20,8 @@ require (
 	github.com/mitchellh/copystructure v1.2.0 // indirect
 	github.com/mitchellh/reflectwalk v1.0.2 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
+	go.opentelemetry.io/collector/featuregate v1.12.0 // indirect
+	go.opentelemetry.io/collector/internal/globalgates v0.106.1 // indirect
 	go.uber.org/multierr v1.11.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

From b6aee54cea5eaa3ff69783410272257f9caea933 Mon Sep 17 00:00:00 2001
From: Tyler Helmuth <12352919+TylerHelmuth@users.noreply.github.com>
Date: Wed, 7 Aug 2024 13:38:59 -0600
Subject: [PATCH 11/13] Update comments

---
 confmap/converter/expandconverter/expand.go | 6 ++++--
 confmap/converter/expandconverter/go.mod    | 3 ++-
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/confmap/converter/expandconverter/expand.go b/confmap/converter/expandconverter/expand.go
index b651ec6fda3..6d66498828a 100644
--- a/confmap/converter/expandconverter/expand.go
+++ b/confmap/converter/expandconverter/expand.go
@@ -24,7 +24,8 @@ type converter struct {
 // NewFactory returns a factory for a  confmap.Converter,
 // which expands all environment variables for a given confmap.Conf.
 //
-// Deprecated: [v0.107.0] BASH-style env var expansion is deprecated. Use `${FOO}` or `${env:FOO}` instead.
+// Deprecated: [v0.107.0] BASH-style env var expansion is deprecated. Use the `envprovider` instead to expand `${FOO}` and `${env:FOO}`.
+// Using the expandconverter will cause double escaping, so `$$$$` -> `$` instead of `$$`.
 func NewFactory() confmap.ConverterFactory {
 	return confmap.NewConverterFactory(newConverter)
 }
@@ -36,7 +37,8 @@ func newConverter(set confmap.ConverterSettings) confmap.Converter {
 	}
 }
 
-// Deprecated: [v0.107.0] BASH-style env var expansion is deprecated. Use `${FOO}` or `${env:FOO}` instead.
+// Deprecated: [v0.107.0] BASH-style env var expansion is deprecated. Use the `envprovider` instead to expand `${FOO}` and `${env:FOO}`.
+// Using the expandconverter will cause double escaping, so `$$$$` -> `$` instead of `$$`.
 func (c converter) Convert(_ context.Context, conf *confmap.Conf) error {
 	var err error
 	out := make(map[string]any)
diff --git a/confmap/converter/expandconverter/go.mod b/confmap/converter/expandconverter/go.mod
index fc66216a4f4..8b710e5663a 100644
--- a/confmap/converter/expandconverter/go.mod
+++ b/confmap/converter/expandconverter/go.mod
@@ -1,4 +1,5 @@
-// Deprecated: [v0.107.0] BASH-style env var expansion is deprecated. Use `${FOO}` or `${env:FOO}` instead.
+// Deprecated: [v0.107.0] BASH-style env var expansion is deprecated. Use the `envprovider` instead to expand `${FOO}` and `${env:FOO}`.
+// Using the expandconverter will cause double escaping, so `$$$$` -> `$` instead of `$$`.                                                                                                           //// Using the expandconverter will cause double escaping, so `$$$$` -> `$` instead of `$$`.
 module go.opentelemetry.io/collector/confmap/converter/expandconverter
 
 go 1.21.0

From e6fef5a35b85836c891d289f76b06fa3c1ce98c7 Mon Sep 17 00:00:00 2001
From: Tyler Helmuth <12352919+TylerHelmuth@users.noreply.github.com>
Date: Wed, 7 Aug 2024 13:58:55 -0600
Subject: [PATCH 12/13] Update confmap/converter/expandconverter/go.mod

Co-authored-by: Dmitrii Anoshin <anoshindx@gmail.com>
---
 confmap/converter/expandconverter/go.mod | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/confmap/converter/expandconverter/go.mod b/confmap/converter/expandconverter/go.mod
index 8b710e5663a..8701827566b 100644
--- a/confmap/converter/expandconverter/go.mod
+++ b/confmap/converter/expandconverter/go.mod
@@ -1,5 +1,5 @@
 // Deprecated: [v0.107.0] BASH-style env var expansion is deprecated. Use the `envprovider` instead to expand `${FOO}` and `${env:FOO}`.
-// Using the expandconverter will cause double escaping, so `$$$$` -> `$` instead of `$$`.                                                                                                           //// Using the expandconverter will cause double escaping, so `$$$$` -> `$` instead of `$$`.
+// Using the expandconverter will cause double escaping, so `$$$$` -> `$` instead of `$$`.
 module go.opentelemetry.io/collector/confmap/converter/expandconverter
 
 go 1.21.0

From 9aefa5ecfc04487df04f1276a5f48fff23c89160 Mon Sep 17 00:00:00 2001
From: Tyler Helmuth <12352919+TylerHelmuth@users.noreply.github.com>
Date: Wed, 7 Aug 2024 14:01:25 -0600
Subject: [PATCH 13/13] Update comments

---
 confmap/converter/expandconverter/expand.go | 4 ++--
 confmap/converter/expandconverter/go.mod    | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/confmap/converter/expandconverter/expand.go b/confmap/converter/expandconverter/expand.go
index 6d66498828a..83b8e4b9dd9 100644
--- a/confmap/converter/expandconverter/expand.go
+++ b/confmap/converter/expandconverter/expand.go
@@ -25,7 +25,7 @@ type converter struct {
 // which expands all environment variables for a given confmap.Conf.
 //
 // Deprecated: [v0.107.0] BASH-style env var expansion is deprecated. Use the `envprovider` instead to expand `${FOO}` and `${env:FOO}`.
-// Using the expandconverter will cause double escaping, so `$$$$` -> `$` instead of `$$`.
+// Using the expandconverter with `confmap.Resolver` will cause double escaping, so `$$$$` -> `$` instead of `$$`.
 func NewFactory() confmap.ConverterFactory {
 	return confmap.NewConverterFactory(newConverter)
 }
@@ -38,7 +38,7 @@ func newConverter(set confmap.ConverterSettings) confmap.Converter {
 }
 
 // Deprecated: [v0.107.0] BASH-style env var expansion is deprecated. Use the `envprovider` instead to expand `${FOO}` and `${env:FOO}`.
-// Using the expandconverter will cause double escaping, so `$$$$` -> `$` instead of `$$`.
+// Using the expandconverter with `confmap.Resolver` will cause double escaping, so `$$$$` -> `$` instead of `$$`.
 func (c converter) Convert(_ context.Context, conf *confmap.Conf) error {
 	var err error
 	out := make(map[string]any)
diff --git a/confmap/converter/expandconverter/go.mod b/confmap/converter/expandconverter/go.mod
index 8701827566b..60b4d680b5b 100644
--- a/confmap/converter/expandconverter/go.mod
+++ b/confmap/converter/expandconverter/go.mod
@@ -1,5 +1,5 @@
 // Deprecated: [v0.107.0] BASH-style env var expansion is deprecated. Use the `envprovider` instead to expand `${FOO}` and `${env:FOO}`.
-// Using the expandconverter will cause double escaping, so `$$$$` -> `$` instead of `$$`.
+// Using the expandconverter with `confmap.Resolver` will cause double escaping, so `$$$$` -> `$` instead of `$$`.
 module go.opentelemetry.io/collector/confmap/converter/expandconverter
 
 go 1.21.0