Merge pull request #135 from digitalocean/agandhi/config-updates

config: cleanup, add env var support

CHANGELOG.md

@@ -2,6 +2,16 @@
 
 ## [Unreleased](https://github.com/digitalocean/droplet-agent/tree/HEAD)
 
+## [1.2.9](https://github.com/digitalocean/droplet-agent/tree/1.2.9) (2024-12-11)
+### Updated
+- config: include version in user agent
+- config: simplify backgroundJobInterval
+- config: export and use Version const directly
+- config: add support for environment variables
+
+### Related PRs
+- config: cleanup, add env var support [\#135](https://github.com/digitalocean/droplet-agent/pull/135)
+
 ## [1.2.8](https://github.com/digitalocean/droplet-agent/tree/1.2.8) (2024-06-14)
 ### Updated
 - Properly close the response body when requesting metadata service to avoid memory leak

Makefile

@@ -111,7 +111,7 @@ endif
 internal/config/version.go:
 	$(print)
 	@printf "version = v%s" $(VERSION)
-	@printf "// SPDX-License-Identifier: Apache-2.0\n\npackage config\n\nconst version = \"v%s\"\n" $(VERSION) > $@
+	@printf "// SPDX-License-Identifier: Apache-2.0\n\npackage config\n\n// Version is the current package version.\nconst Version = \"v%s\"\n" $(VERSION) > $@
 
 .PHONY: target/VERSION internal/config/version.go
 target/VERSION:

cmd/agent/main.go

@@ -25,7 +25,7 @@ func main() {
 	log.Info("Launching %s", config.AppFullName)
 	cfg := config.Init()
 
-	log.Info("Config Loaded. Agent Starting (version:%s)", cfg.Version)
+	log.Info("Config Loaded. Agent Starting (version:%s)", config.Version)
 
 	if cfg.DebugMode {
 		log.EnableDebug()

go.mod

@@ -5,6 +5,7 @@ go 1.22
 require (
 	github.com/fsnotify/fsnotify v1.7.0
 	github.com/opencontainers/selinux v1.11.0
+	github.com/peterbourgon/ff/v3 v3.4.0
 	go.uber.org/mock v0.4.0
 	golang.org/x/crypto v0.28.0
 	golang.org/x/net v0.30.0

go.sum

@@ -2,6 +2,8 @@ github.com/fsnotify/fsnotify v1.7.0 h1:8JEhPFa5W2WU7YfeZzPNqzMP6Lwt7L2715Ggo0nos
 github.com/fsnotify/fsnotify v1.7.0/go.mod h1:40Bi/Hjc2AVfZrqy+aj+yEI+/bRxZnMJyTJwOpGvigM=
 github.com/opencontainers/selinux v1.11.0 h1:+5Zbo97w3Lbmb3PeqQtpmTkMwsW5nRI3YaLpt7tQ7oU=
 github.com/opencontainers/selinux v1.11.0/go.mod h1:E5dMC3VPuVvVHDYmi78qvhJp8+M586T4DlDRYpFkyec=
+github.com/peterbourgon/ff/v3 v3.4.0 h1:QBvM/rizZM1cB0p0lGMdmR7HxZeI/ZrBWB4DqLkMUBc=
+github.com/peterbourgon/ff/v3 v3.4.0/go.mod h1:zjJVUhx+twciwfDl0zBcFzl4dW8axCRyXE/eKY9RztQ=
 go.uber.org/mock v0.4.0 h1:VcM4ZOtdbR4f6VXfiOpwpVJDL6lCReaZ6mw31wqh7KU=
 go.uber.org/mock v0.4.0/go.mod h1:a6FSlNadKUHUa9IP5Vyt1zh4fC7uAwxMutEAscFbkZc=
 golang.org/x/crypto v0.28.0 h1:GBDwsMXVQi34v5CCYUm2jkJvu4cbtru2U4TN2PSyQnw=

internal/config/config.go

@@ -2,37 +2,50 @@
 
 package config
 
-import "time"
+import (
+	"flag"
+	"os"
+	"time"
+
+	"github.com/peterbourgon/ff/v3"
+)
 
 const (
 	AppFullName  = "DigitalOcean Droplet Agent (code name: DOTTY)"
 	AppShortName = "Droplet Agent"
 	AppDebugAddr = "127.0.0.1:304"
-)
 
-const (
-	backgroundJobIntervalSeconds = 120
+	UserAgent = "Droplet-Agent/" + Version
+
+	backgroundJobInterval = 120 * time.Second
 )
 
 // Conf contains the configurations needed to run the agent
 type Conf struct {
-	Version                     string
-	UseSyslog                   bool
-	DebugMode                   bool
-	AuthorizedKeysCheckInterval time.Duration
+	UseSyslog bool
+	DebugMode bool
+
 	CustomSSHDPort              int
 	CustomSSHDCfgFile           string
+	AuthorizedKeysCheckInterval time.Duration
 }
 
 // Init initializes the agent's configuration
 func Init() *Conf {
-	cliArgs := parseCLIArgs()
-	return &Conf{
-		Version:                     version,
-		UseSyslog:                   cliArgs.useSyslog,
-		DebugMode:                   cliArgs.debugMode,
-		CustomSSHDPort:              cliArgs.sshdPort,
-		CustomSSHDCfgFile:           cliArgs.sshdCfgFile,
-		AuthorizedKeysCheckInterval: backgroundJobIntervalSeconds * time.Second,
+	cfg := Conf{
+		AuthorizedKeysCheckInterval: backgroundJobInterval,
 	}
+
+	fs := flag.NewFlagSet("droplet-agent", flag.ExitOnError)
+
+	fs.BoolVar(&cfg.UseSyslog, "syslog", false, "Use syslog service for logging")
+	fs.BoolVar(&cfg.DebugMode, "debug", false, "Turn on debug mode")
+	fs.IntVar(&cfg.CustomSSHDPort, "sshd_port", 0, "The port sshd is binding to")
+	fs.StringVar(&cfg.CustomSSHDCfgFile, "sshd_config", "", "The location of sshd_config")
+
+	ff.Parse(fs, os.Args[1:],
+		ff.WithEnvVarPrefix("DROPLET_AGENT"),
+	)
+
+	return &cfg
 }

internal/config/version.go

@@ -2,4 +2,5 @@
 
 package config
 
-const version = "v1.2.8"
+// Version is the current package version.
+const Version = "v1.2.9"

internal/metadata/updater/updater.go

@@ -8,6 +8,7 @@ import (
 	"fmt"
 	"net/http"
 
+	"github.com/digitalocean/droplet-agent/internal/config"
 	"github.com/digitalocean/droplet-agent/internal/metadata"
 )
 
@@ -37,7 +38,7 @@ func (u *agentInfoUpdaterImpl) Update(md *metadata.Metadata) error {
 		return fmt.Errorf("%w:%v", ErrUpdateMetadataFailed, err)
 	}
 
-	req.Header.Set("User-Agent", "Droplet-Agent/1.0.1")
+	req.Header.Set("User-Agent", config.UserAgent)
 	req.Header.Set("Content-Type", "application/json; charset=utf-8")
 	resp, err := u.client.Do(req)
 	if err != nil {

internal/metadata/updater/updater_test.go

@@ -9,6 +9,7 @@ import (
 	"net/http"
 	"testing"
 
+	"github.com/digitalocean/droplet-agent/internal/config"
 	"github.com/digitalocean/droplet-agent/internal/metadata"
 	"github.com/digitalocean/droplet-agent/internal/mockutils"
 	"go.uber.org/mock/gomock"
@@ -89,7 +90,7 @@ func newRequest(t *testing.T, body []byte) *http.Request {
 		t.Fatalf("could not create http request: %s", err)
 	}
 	req.Header.Set("Content-Type", "application/json; charset=utf-8")
-	req.Header.Set("User-Agent", "Droplet-Agent/1.0.1")
+	req.Header.Set("User-Agent", config.UserAgent)
 
 	return req
 }