feat: extend --version with commit, date, dirty flag, and build profile

.goreleaser.yml

@@ -4,7 +4,7 @@ builds:
   - main: ./cmd/sidecar
     binary: sidecar
     ldflags:
-      - -s -w -X main.Version={{ .Version }}
+      - -s -w -X main.Version={{ .Version }} -X main.Commit={{ .ShortCommit }} -X main.Dirty=false -X main.BuildDate={{ .Date }} -X main.BuildProfile=release
     env:
       - CGO_ENABLED=0
     goos:

Makefile

@@ -5,19 +5,31 @@ all: build
 
 LINT_BASE ?= main
 
+# Build metadata injected into every binary via ldflags.
+VERSION      ?= $(shell git describe --tags --always 2>/dev/null || echo "dev")
+COMMIT       := $(shell git rev-parse --short HEAD 2>/dev/null || echo "unknown")
+IS_DIRTY     := $(shell git diff --quiet 2>/dev/null && git diff --cached --quiet 2>/dev/null && echo "false" || echo "true")
+BUILD_DATE   := $(shell date -u +%Y-%m-%dT%H:%M:%SZ)
+BUILD_PROFILE ?= debug
+
+LDFLAGS := -X main.Version=$(VERSION) \
+           -X main.Commit=$(COMMIT) \
+           -X main.Dirty=$(IS_DIRTY) \
+           -X main.BuildDate=$(BUILD_DATE) \
+           -X main.BuildProfile=$(BUILD_PROFILE)
+
 # Build the binary
 build:
-	go build -o bin/sidecar ./cmd/sidecar
+	go build -ldflags "$(LDFLAGS)" -o bin/sidecar ./cmd/sidecar
 
 # Install to GOBIN
 install:
-	go install ./cmd/sidecar
+	go install -ldflags "$(LDFLAGS)" ./cmd/sidecar
 
-# Install with version info from git
+# Install with version info from git (explicit dev profile)
 install-dev:
-	$(eval VERSION := $(shell git describe --tags --always --dirty 2>/dev/null || echo "dev"))
-	@echo "Installing sidecar with Version=$(VERSION)"
-	go install -ldflags "-X main.Version=$(VERSION)" ./cmd/sidecar
+	@echo "Installing sidecar version=$(VERSION) commit=$(COMMIT) dirty=$(IS_DIRTY)"
+	go install -ldflags "$(LDFLAGS)" ./cmd/sidecar
 
 # Run tests
 test:
@@ -95,10 +107,10 @@ lint-all:
 
 # Build for multiple platforms (local testing only — GoReleaser handles release builds)
 build-all:
-	GOOS=darwin GOARCH=amd64 go build -o bin/sidecar-darwin-amd64 ./cmd/sidecar
-	GOOS=darwin GOARCH=arm64 go build -o bin/sidecar-darwin-arm64 ./cmd/sidecar
-	GOOS=linux GOARCH=amd64 go build -o bin/sidecar-linux-amd64 ./cmd/sidecar
-	GOOS=linux GOARCH=arm64 go build -o bin/sidecar-linux-arm64 ./cmd/sidecar
+	GOOS=darwin GOARCH=amd64 go build -ldflags "$(LDFLAGS)" -o bin/sidecar-darwin-amd64 ./cmd/sidecar
+	GOOS=darwin GOARCH=arm64 go build -ldflags "$(LDFLAGS)" -o bin/sidecar-darwin-arm64 ./cmd/sidecar
+	GOOS=linux GOARCH=amd64 go build -ldflags "$(LDFLAGS)" -o bin/sidecar-linux-amd64 ./cmd/sidecar
+	GOOS=linux GOARCH=arm64 go build -ldflags "$(LDFLAGS)" -o bin/sidecar-linux-arm64 ./cmd/sidecar
 
 # Test GoReleaser locally (creates snapshot build without publishing)
 goreleaser-snapshot:

cmd/sidecar/main.go

@@ -43,8 +43,14 @@ import (
 	"golang.org/x/term"
 )
 
-// Version is set at build time via ldflags
-var Version = ""
+// Build-time variables set via ldflags.
+var (
+	Version      = "" // semantic version (e.g. v0.78.0)
+	Commit       = "" // short git commit hash
+	Dirty        = "" // "true" if working tree was dirty at build time
+	BuildDate    = "" // RFC3339 build timestamp
+	BuildProfile = "" // "release" or "debug"
+)
 
 var (
 	configPath     = flag.String("config", "", "path to config file")
@@ -80,7 +86,7 @@ func main() {
 
 	// Handle version flag
 	if *versionFlag || *shortVersion {
-		fmt.Printf("sidecar version %s\n", effectiveVersion(Version))
+		printVersionInfo()
 		os.Exit(0)
 	}
 
@@ -266,6 +272,76 @@ func effectiveVersion(v string) string {
 	return "devel"
 }
 
+// vcsInfo holds build-time VCS metadata resolved from ldflags or debug.ReadBuildInfo.
+type vcsInfo struct {
+	commit  string
+	dirty   bool
+	date    string
+	profile string
+}
+
+// resolveVCSInfo returns build metadata, preferring ldflags values and falling
+// back to debug.ReadBuildInfo when ldflags were not injected.
+func resolveVCSInfo() vcsInfo {
+	info := vcsInfo{
+		commit:  Commit,
+		dirty:   Dirty == "true",
+		date:    BuildDate,
+		profile: BuildProfile,
+	}
+
+	// Fill in anything missing from debug.ReadBuildInfo (dev builds).
+	if info.commit == "" || info.date == "" {
+		if bi, ok := debug.ReadBuildInfo(); ok {
+			for _, s := range bi.Settings {
+				switch s.Key {
+				case "vcs.revision":
+					if info.commit == "" {
+						if len(s.Value) > 7 {
+							info.commit = s.Value[:7]
+						} else {
+							info.commit = s.Value
+						}
+					}
+				case "vcs.modified":
+					if Dirty == "" {
+						info.dirty = s.Value == "true"
+					}
+				case "vcs.time":
+					if info.date == "" {
+						info.date = s.Value
+					}
+				}
+			}
+		}
+	}
+
+	if info.profile == "" {
+		info.profile = "development"
+	}
+
+	return info
+}
+
+// printVersionInfo prints detailed build information to stdout.
+func printVersionInfo() {
+	ver := effectiveVersion(Version)
+	vcs := resolveVCSInfo()
+
+	fmt.Printf("sidecar %s\n", ver)
+	if vcs.commit != "" {
+		if vcs.dirty {
+			fmt.Printf("  commit:  %s (dirty)\n", vcs.commit)
+		} else {
+			fmt.Printf("  commit:  %s\n", vcs.commit)
+		}
+	}
+	if vcs.date != "" {
+		fmt.Printf("  date:    %s\n", vcs.date)
+	}
+	fmt.Printf("  profile: %s\n", vcs.profile)
+}
+
 func init() {
 	// Customize usage output
 	flag.Usage = func() {