feat: Add buildinfo package to embed version (#840)

This also resolves build time and commit hash using the
Go 1.18 debug/buildinfo package. An external URL is outputted
on running version as well to easily route the caller to a
release or commit.

.goreleaser.yml

@@ -16,7 +16,7 @@ before:
 builds:
   - id: coder-slim
     dir: cmd/coder
-    ldflags: ["-s -w"]
+    ldflags: ["-s -w -X github.com/coder/coder/cli/buildinfo.tag={{ .Version }}"]
     env: [CGO_ENABLED=0]
     goos: [darwin, linux, windows]
     goarch: [amd64]
@@ -28,7 +28,7 @@ builds:
   - id: coder
     dir: cmd/coder
     flags: [-tags=embed]
-    ldflags: ["-s -w"]
+    ldflags: ["-s -w -X github.com/coder/coder/cli/buildinfo.tag={{ .Version }}"]
     env: [CGO_ENABLED=0]
     goos: [darwin, linux, windows]
     goarch: [amd64, arm64]
@@ -58,3 +58,6 @@ nfpms:
 
 release:
   ids: [coder, packages]
+
+snapshot:
+  name_template: '{{ .Version }}-devel+{{ .ShortCommit }}'

.vscode/settings.json

@@ -5,6 +5,7 @@
     "coderd",
     "coderdtest",
     "codersdk",
+    "devel",
     "drpc",
     "drpcconn",
     "drpcmux",

cli/buildinfo/buildinfo.go

@@ -0,0 +1,83 @@
+package buildinfo
+
+import (
+	"path"
+	"runtime/debug"
+	"sync"
+	"time"
+
+	"golang.org/x/mod/semver"
+)
+
+var (
+	buildInfo      *debug.BuildInfo
+	buildInfoValid bool
+	readBuildInfo  sync.Once
+
+	// Injected with ldflags at build!
+	tag string
+)
+
+// Version returns the semantic version of the build.
+// Use golang.org/x/mod/semver to compare versions.
+func Version() string {
+	revision, valid := revision()
+	if valid {
+		revision = "+" + revision[:7]
+	}
+	if tag == "" {
+		return "v0.0.0-devel" + revision
+	}
+	if semver.Build(tag) == "" {
+		tag += revision
+	}
+	return "v" + tag
+}
+
+// ExternalURL returns a URL referencing the current Coder version.
+// For production builds, this will link directly to a release.
+// For development builds, this will link to a commit.
+func ExternalURL() string {
+	repo := "https://github.com/coder/coder"
+	revision, valid := revision()
+	if !valid {
+		return repo
+	}
+	return path.Join(repo, "commit", revision)
+}
+
+// Time returns when the Git revision was published.
+func Time() (time.Time, bool) {
+	value, valid := find("vcs.time")
+	if !valid {
+		return time.Time{}, false
+	}
+	parsed, err := time.Parse(time.RFC3339, value)
+	if err != nil {
+		panic("couldn't parse time: " + err.Error())
+	}
+	return parsed, true
+}
+
+// revision returns the Git hash of the build.
+func revision() (string, bool) {
+	return find("vcs.revision")
+}
+
+// find panics if a setting with the specific key was not
+// found in the build info.
+func find(key string) (string, bool) {
+	readBuildInfo.Do(func() {
+		buildInfo, buildInfoValid = debug.ReadBuildInfo()
+	})
+	if !buildInfoValid {
+		panic("couldn't read build info")
+	}
+	for _, setting := range buildInfo.Settings {
+		if setting.Key != key {
+			continue
+		}
+		return setting.Value, true
+	}
+	return "", false
+}

cli/buildinfo/buildinfo_test.go

@@ -0,0 +1,32 @@
+package buildinfo_test
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+	"golang.org/x/mod/semver"
+
+	"github.com/coder/coder/cli/buildinfo"
+)
+
+func TestBuildInfo(t *testing.T) {
+	t.Parallel()
+	t.Run("Version", func(t *testing.T) {
+		t.Parallel()
+		version := buildinfo.Version()
+		require.True(t, semver.IsValid(version))
+		prerelease := semver.Prerelease(version)
+		require.Equal(t, "-devel", prerelease)
+		require.Equal(t, "v0", semver.Major(version))
+	})
+	t.Run("ExternalURL", func(t *testing.T) {
+		t.Parallel()
+		require.Equal(t, "https://github.com/coder/coder", buildinfo.ExternalURL())
+	})
+	// Tests don't include Go build info.
+	t.Run("NoTime", func(t *testing.T) {
+		t.Parallel()
+		_, valid := buildinfo.Time()
+		require.False(t, valid)
+	})
+}

cli/root.go

@@ -4,12 +4,14 @@ import (
 	"net/url"
 	"os"
 	"strings"
+	"time"
 
 	"github.com/charmbracelet/lipgloss"
 	"github.com/kirsle/configdir"
 	"github.com/mattn/go-isatty"
 	"github.com/spf13/cobra"
 
+	"github.com/coder/coder/cli/buildinfo"
 	"github.com/coder/coder/cli/cliui"
 	"github.com/coder/coder/cli/config"
 	"github.com/coder/coder/codersdk"
@@ -28,6 +30,7 @@ const (
 func Root() *cobra.Command {
 	cmd := &cobra.Command{
 		Use:          "coder",
+		Version:      buildinfo.Version(),
 		SilenceUsage: true,
 		Long: `    ▄█▀    ▀█▄
      ▄▄ ▀▀▀  █▌   ██▀▀█▄          ▐█
@@ -55,6 +58,7 @@ func Root() *cobra.Command {
 		`Flags:`, header.Render("Flags:"),
 		`Additional help topics:`, header.Render("Additional help:"),
 	).Replace(cmd.UsageTemplate()))
+	cmd.SetVersionTemplate(versionTemplate())
 
 	cmd.AddCommand(
 		configSSH(),
@@ -142,3 +146,14 @@ func isTTY(cmd *cobra.Command) bool {
 	}
 	return isatty.IsTerminal(file.Fd())
 }
+
+func versionTemplate() string {
+	template := `Coder {{printf "%s" .Version}}`
+	buildTime, valid := buildinfo.Time()
+	if valid {
+		template += " " + buildTime.Format(time.UnixDate)
+	}
+	template += "\r\n" + buildinfo.ExternalURL()
+	template += "\r\n"
+	return template
+}

go.mod

@@ -237,7 +237,7 @@ require (
 	github.com/zclconf/go-cty v1.10.0 // indirect
 	github.com/zeebo/errs v1.2.2 // indirect
 	go.opencensus.io v0.23.0 // indirect
-	golang.org/x/mod v0.5.1 // indirect
+	golang.org/x/mod v0.5.1
 	golang.org/x/net v0.0.0-20220325170049-de3da57026de // indirect
 	golang.org/x/term v0.0.0-20210927222741-03fcf44c2211
 	golang.org/x/text v0.3.7 // indirect