address PR comments

src/k8s/pkg/k8sd/setup/containerd.go

@@ -139,7 +139,7 @@ func Containerd(snap snap.Snap, registries []types.ContainerdRegistry, extraArgs
 	}
 
 	// Apply extra arguments after the defaults, so they can override them.
-	updateArgs, deleteArgs := snaputil.ServiceArgsFromMap(extraArgs)
+	updateArgs, deleteArgs := utils.ServiceArgsFromMap(extraArgs)
 	if _, err := snaputil.UpdateServiceArguments(snap, "containerd", updateArgs, deleteArgs); err != nil {
 		return fmt.Errorf("failed to write arguments file: %w", err)
 	}

src/k8s/pkg/k8sd/setup/k8s_apiserver_proxy.go

@@ -7,6 +7,7 @@ import (
 	"github.com/canonical/k8s/pkg/proxy"
 	"github.com/canonical/k8s/pkg/snap"
 	snaputil "github.com/canonical/k8s/pkg/snap/util"
+	"github.com/canonical/k8s/pkg/utils"
 )
 
 // K8sAPIServerProxy prepares configuration for k8s-apiserver-proxy.
@@ -25,7 +26,7 @@ func K8sAPIServerProxy(snap snap.Snap, servers []string, extraArgs map[string]*s
 	}
 
 	// Apply extra arguments after the defaults, so they can override them.
-	updateArgs, deleteArgs := snaputil.ServiceArgsFromMap(extraArgs)
+	updateArgs, deleteArgs := utils.ServiceArgsFromMap(extraArgs)
 	if _, err := snaputil.UpdateServiceArguments(snap, "k8s-apiserver-proxy", updateArgs, deleteArgs); err != nil {
 		return fmt.Errorf("failed to write arguments file: %w", err)
 	}

src/k8s/pkg/k8sd/setup/k8s_dqlite.go

@@ -7,6 +7,7 @@ import (
 
 	"github.com/canonical/k8s/pkg/snap"
 	snaputil "github.com/canonical/k8s/pkg/snap/util"
+	"github.com/canonical/k8s/pkg/utils"
 	"gopkg.in/yaml.v2"
 )
 
@@ -33,7 +34,7 @@ func K8sDqlite(snap snap.Snap, address string, cluster []string, extraArgs map[s
 	}
 
 	// Apply extra arguments after the defaults, so they can override them.
-	updateArgs, deleteArgs := snaputil.ServiceArgsFromMap(extraArgs)
+	updateArgs, deleteArgs := utils.ServiceArgsFromMap(extraArgs)
 	if _, err := snaputil.UpdateServiceArguments(snap, "k8s-dqlite", updateArgs, deleteArgs); err != nil {
 		return fmt.Errorf("failed to write arguments file: %w", err)
 	}

src/k8s/pkg/k8sd/setup/kube_apiserver.go

@@ -9,6 +9,7 @@ import (
 	"github.com/canonical/k8s/pkg/k8sd/types"
 	"github.com/canonical/k8s/pkg/snap"
 	snaputil "github.com/canonical/k8s/pkg/snap/util"
+	"github.com/canonical/k8s/pkg/utils"
 )
 
 type apiserverAuthTokenWebhookTemplateConfig struct {
@@ -107,7 +108,7 @@ func KubeAPIServer(snap snap.Snap, serviceCIDR string, authWebhookURL string, en
 	}
 
 	// Apply extra arguments after the defaults, so they can override them.
-	updateArgs, deleteArgs := snaputil.ServiceArgsFromMap(extraArgs)
+	updateArgs, deleteArgs := utils.ServiceArgsFromMap(extraArgs)
 	if _, err := snaputil.UpdateServiceArguments(snap, "kube-apiserver", updateArgs, deleteArgs); err != nil {
 		return fmt.Errorf("failed to write arguments file: %w", err)
 	}

src/k8s/pkg/k8sd/setup/kube_controller_manager.go

@@ -7,6 +7,7 @@ import (
 
 	"github.com/canonical/k8s/pkg/snap"
 	snaputil "github.com/canonical/k8s/pkg/snap/util"
+	"github.com/canonical/k8s/pkg/utils"
 )
 
 // KubeControllerManager configures kube-controller-manager on the local node.
@@ -31,7 +32,7 @@ func KubeControllerManager(snap snap.Snap, extraArgs map[string]*string) error {
 		return fmt.Errorf("failed to render arguments file: %w", err)
 	}
 	// Apply extra arguments after the defaults, so they can override them.
-	updateArgs, deleteArgs := snaputil.ServiceArgsFromMap(extraArgs)
+	updateArgs, deleteArgs := utils.ServiceArgsFromMap(extraArgs)
 	if _, err := snaputil.UpdateServiceArguments(snap, "kube-controller-manager", updateArgs, deleteArgs); err != nil {
 		return fmt.Errorf("failed to write arguments file: %w", err)
 	}

src/k8s/pkg/k8sd/setup/kube_proxy.go

@@ -8,6 +8,7 @@ import (
 
 	"github.com/canonical/k8s/pkg/snap"
 	snaputil "github.com/canonical/k8s/pkg/snap/util"
+	"github.com/canonical/k8s/pkg/utils"
 )
 
 // KubeProxy configures kube-proxy on the local node.
@@ -35,7 +36,7 @@ func KubeProxy(ctx context.Context, snap snap.Snap, hostname string, podCIDR str
 	}
 
 	// Apply extra arguments after the defaults, so they can override them.
-	updateArgs, deleteArgs := snaputil.ServiceArgsFromMap(extraArgs)
+	updateArgs, deleteArgs := utils.ServiceArgsFromMap(extraArgs)
 	if _, err := snaputil.UpdateServiceArguments(snap, "kube-proxy", updateArgs, deleteArgs); err != nil {
 		return fmt.Errorf("failed to write arguments file: %w", err)
 	}

src/k8s/pkg/k8sd/setup/kube_scheduler.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/canonical/k8s/pkg/snap"
 	snaputil "github.com/canonical/k8s/pkg/snap/util"
+	"github.com/canonical/k8s/pkg/utils"
 )
 
 // KubeScheduler configures kube-scheduler on the local node.
@@ -21,7 +22,7 @@ func KubeScheduler(snap snap.Snap, extraArgs map[string]*string) error {
 		return fmt.Errorf("failed to render arguments file: %w", err)
 	}
 	// Apply extra arguments after the defaults, so they can override them.
-	updateArgs, deleteArgs := snaputil.ServiceArgsFromMap(extraArgs)
+	updateArgs, deleteArgs := utils.ServiceArgsFromMap(extraArgs)
 	if _, err := snaputil.UpdateServiceArguments(snap, "kube-scheduler", updateArgs, deleteArgs); err != nil {
 		return fmt.Errorf("failed to write arguments file: %w", err)
 	}

src/k8s/pkg/k8sd/setup/kubelet.go

@@ -8,6 +8,7 @@ import (
 
 	"github.com/canonical/k8s/pkg/snap"
 	snaputil "github.com/canonical/k8s/pkg/snap/util"
+	"github.com/canonical/k8s/pkg/utils"
 )
 
 var kubeletTLSCipherSuites = []string{
@@ -76,7 +77,7 @@ func kubelet(snap snap.Snap, hostname string, nodeIP net.IP, clusterDNS string,
 	}
 
 	// Apply extra arguments after the defaults, so they can override them.
-	updateArgs, deleteArgs := snaputil.ServiceArgsFromMap(extraArgs)
+	updateArgs, deleteArgs := utils.ServiceArgsFromMap(extraArgs)
 	if _, err := snaputil.UpdateServiceArguments(snap, "kubelet", updateArgs, deleteArgs); err != nil {
 		return fmt.Errorf("failed to write arguments file: %w", err)
 	}

src/k8s/pkg/k8sd/setup/util_extra_files.go

@@ -19,27 +19,15 @@ func ExtraNodeConfigFiles(snap snap.Snap, files map[string]string) error {
 		}
 
 		filePath := path.Join(snap.ServiceExtraConfigDir(), filename)
-		// Create or truncate the file
-		file, err := os.Create(filePath)
-		if err != nil {
-			return fmt.Errorf("failed to create file %s: %w", filePath, err)
-		}
-		defer file.Close()
-
 		// Write the content to the file
-		_, err = file.WriteString(content)
-		if err != nil {
+		if err := os.WriteFile(filePath, []byte(content), 0400); err != nil {
 			return fmt.Errorf("failed to write to file %s: %w", filePath, err)
 		}
 
 		// Set file owner to root
 		if err := os.Chown(filePath, snap.UID(), snap.GID()); err != nil {
 			return fmt.Errorf("failed to change owner of file %s: %w", filePath, err)
 		}
-
-		if err := os.Chmod(filePath, 0400); err != nil {
-			return fmt.Errorf("failed to change mode of file %s: %w", filePath, err)
-		}
 	}
 	return nil
 }

src/k8s/pkg/utils/services.go

@@ -0,0 +1,18 @@
+package utils
+
+// ServiceArgsFromMap processes a map of string pointers and categorizes them into update and delete lists.
+// - If the value pointer is nil, it adds the argument name to the delete list.
+// - If the value pointer is not nil, it adds the argument and its value to the update map.
+func ServiceArgsFromMap(args map[string]*string) (map[string]string, []string) {
+	updateArgs := make(map[string]string)
+	deleteArgs := make([]string, 0)
+
+	for arg, val := range args {
+		if val == nil {
+			deleteArgs = append(deleteArgs, arg)
+		} else {
+			updateArgs[arg] = *val
+		}
+	}
+	return updateArgs, deleteArgs
+}

src/k8s/pkg/utils/services_test.go

@@ -0,0 +1,77 @@
+package utils
+
+import (
+	"testing"
+
+	. "github.com/onsi/gomega"
+)
+
+func TestServiceArgsFromMap(t *testing.T) {
+	tests := []struct {
+		name     string
+		input    map[string]*string
+		expected struct {
+			updateArgs map[string]string
+			deleteArgs []string
+		}
+	}{
+		{
+			name:  "NilValue",
+			input: map[string]*string{"arg1": nil},
+			expected: struct {
+				updateArgs map[string]string
+				deleteArgs []string
+			}{
+				updateArgs: map[string]string{},
+				deleteArgs: []string{"arg1"},
+			},
+		},
+		{
+			name:  "EmptyString", // Should be threated as normal string
+			input: map[string]*string{"arg1": Pointer("")},
+			expected: struct {
+				updateArgs map[string]string
+				deleteArgs []string
+			}{
+				updateArgs: map[string]string{"arg1": ""},
+				deleteArgs: []string{},
+			},
+		},
+		{
+			name:  "NonEmptyString",
+			input: map[string]*string{"arg1": Pointer("value1")},
+			expected: struct {
+				updateArgs map[string]string
+				deleteArgs []string
+			}{
+				updateArgs: map[string]string{"arg1": "value1"},
+				deleteArgs: []string{},
+			},
+		},
+		{
+			name: "MixedValues",
+			input: map[string]*string{
+				"arg1": Pointer("value1"),
+				"arg2": Pointer(""),
+				"arg3": nil,
+			},
+			expected: struct {
+				updateArgs map[string]string
+				deleteArgs []string
+			}{
+				updateArgs: map[string]string{"arg1": "value1", "arg2": ""},
+				deleteArgs: []string{"arg3"},
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			g := NewWithT(t)
+
+			updateArgs, deleteArgs := ServiceArgsFromMap(tt.input)
+			g.Expect(updateArgs).To(Equal(tt.expected.updateArgs))
+			g.Expect(deleteArgs).To(Equal(tt.expected.deleteArgs))
+		})
+	}
+}

tests/integration/templates/bootstrap-session.yaml

@@ -15,19 +15,3 @@ cluster-config:
     enabled: true
   metrics-server:
     enabled: true
-extra-node-config-files:
-  bootstrap-extra-file.yaml: extra-args-test-file-content
-extra-node-kube-apiserver-args:
-  --request-timeout: 2m
-extra-node-kube-controller-manager-args:
-  --leader-elect-retry-period: 3s
-extra-node-kube-scheduler-args:
-  --authorization-webhook-cache-authorized-ttl: 11s
-extra-node-kube-proxy-args:
-  --config-sync-period: 14m
-extra-node-kubelet-args:
-  --authentication-token-webhook-cache-ttl: 3m
-extra-node-containerd-args:
-  --log-level: debug
-extra-node-k8s-dqlite-args:
-  --watch-storage-available-size-interval: 6s

tests/integration/templates/bootstrap-smoke.yaml

@@ -0,0 +1,32 @@
+# Contains the bootstrap configuration for the smoke test.
+cluster-config:
+  network:
+    enabled: true
+  dns:
+    enabled: true
+  ingress:
+    enabled: true
+  load-balancer:
+    enabled: true
+  local-storage:
+    enabled: true
+  gateway:
+    enabled: true
+  metrics-server:
+    enabled: true
+extra-node-config-files:
+  bootstrap-extra-file.yaml: extra-args-test-file-content
+extra-node-kube-apiserver-args:
+  --request-timeout: 2m
+extra-node-kube-controller-manager-args:
+  --leader-elect-retry-period: 3s
+extra-node-kube-scheduler-args:
+  --authorization-webhook-cache-authorized-ttl: 11s
+extra-node-kube-proxy-args:
+  --config-sync-period: 14m
+extra-node-kubelet-args:
+  --authentication-token-webhook-cache-ttl: 3m
+extra-node-containerd-args:
+  --log-level: debug
+extra-node-k8s-dqlite-args:
+  --watch-storage-available-size-interval: 6s

tests/integration/tests/test_smoke.py

@@ -2,24 +2,39 @@
 # Copyright 2024 Canonical, Ltd.
 #
 import logging
+from typing import List
 
-from test_util import harness
+import pytest
+from test_util import config, harness, util
 
 LOG = logging.getLogger(__name__)
 
 
-def test_smoke(session_instance: harness.Instance):
+@pytest.mark.node_count(1)
+@pytest.mark.disable_k8s_bootstrapping()
+def test_smoke(instances: List[harness.Instance]):
+    instance = instances[0]
+
+    bootstrap_smoke_config_path = "/home/ubuntu/bootstrap-smoke.yaml"
+    instance.send_file(
+        (config.MANIFESTS_DIR / "bootstrap-smoke.yaml").as_posix(),
+        bootstrap_smoke_config_path,
+    )
+
+    instance.exec(["k8s", "bootstrap", "--file", bootstrap_smoke_config_path])
+    util.wait_until_k8s_ready(instance, [instance])
+
     # Verify the functionality of the k8s config command during the smoke test.
     # It would be excessive to deploy a cluster solely for this purpose.
-    result = session_instance.exec(
+    result = instance.exec(
         "k8s config --server 192.168.210.41".split(), capture_output=True
     )
-    config = result.stdout.decode()
-    assert len(config) > 0
-    assert "server: https://192.168.210.41" in config
+    kubeconfig = result.stdout.decode()
+    assert len(kubeconfig) > 0
+    assert "server: https://192.168.210.41" in kubeconfig
 
     # Verify extra node configs
-    content = session_instance.exec(
+    content = instance.exec(
         ["cat", "/var/snap/k8s/common/args/conf.d/bootstrap-extra-file.yaml"],
         capture_output=True,
     )
@@ -35,7 +50,7 @@ def test_smoke(session_instance: harness.Instance):
         "containerd": "--log-level=debug",
         "k8s-dqlite": "--watch-storage-available-size-interval=6s",
     }.items():
-        args = session_instance.exec(
+        args = instance.exec(
             ["cat", f"/var/snap/k8s/common/args/{service}"], capture_output=True
         )
         assert value in args.stdout.decode()

tests/integration/tests/test_util/util.py

@@ -223,8 +223,8 @@ def get_join_token(
 
 
 # Join an existing cluster.
-def join_cluster(instance: harness.Instance, join_token: str, *args: str):
-    instance.exec(["k8s", "join-cluster", join_token, *args])
+def join_cluster(instance: harness.Instance, join_token: str):
+    instance.exec(["k8s", "join-cluster", join_token])
 
 
 def get_default_cidr(instance: harness.Instance, instance_default_ip: str):