Add build version reporting

docs/cli.md

@@ -10,6 +10,7 @@ defined in [Operations](operations.md).
 
 ~~~
 notarius help
+notarius --version
 notarius run <pipeline-id> --input path/to/source.json [--json] [flags]
 notarius config validate [--config path/to/config.yml] [--pipeline pipeline-id] [--only lane-a,lane-b]
 notarius pipelines list [--config path/to/config.yml] [--json]
@@ -18,6 +19,17 @@ notarius pipelines list [--config path/to/config.yml] [--json]
 Running Notarius without arguments, or with **help**, **--help**, or **-h**,
 writes the command summary to standard output and exits with status 0.
 
+`notarius --version` is valid only as the sole root argument. It writes exactly
+`notarius <version>` followed by a newline to standard output and exits with
+status 0. A tagged `go install` build can report its main-module stable tag,
+and controlled builds can inject a stable tag at link time through
+`gitea.maximumdirect.net/eric/notarius/internal/buildinfo.Override`; an ordinary
+unversioned checkout reports `development`. Invalid injected version content is
+a runtime error with exit status 1, while extra `--version` arguments are a
+syntax error with exit status 2. This diagnostic does not replace the
+[run-result](integrations/run-result.md) or artifact contracts for downstream
+compatibility decisions.
+
 ## run
 
 ~~~

docs/internal/cli.md

@@ -24,10 +24,14 @@ preparation, and runner mechanics after their inputs are supplied.
 
 ## Dispatch And Configuration Handoff
 
-The root dispatcher handles help, configuration validation, pipeline listing,
+The root dispatcher handles help, version reporting, configuration validation,
-and a pipeline run. It normalizes injectable options before dispatch so that a
+pipeline listing, and a pipeline run. Version reporting resolves build
-missing production dependency fails as a command error rather than reaching
+information through `internal/buildinfo` before production composition, so the
-execution.
+diagnostic remains available without configuration or runtime collaborators.
+The public syntax, streams, exit classes, and version semantics are defined by
+the [CLI reference](../cli.md). Other root commands normalize injectable
+options before dispatch so that a missing production dependency fails as a
+command error rather than reaching execution.
 
 Commands that need configuration use one shared loader. The CLI discovers the
 file, parses it through **internal/core/config**, starts from defaults, applies

docs/roadmap/implementation.md

@@ -41,7 +41,7 @@ operation.
 - Tag CI validates only. Pre-publication local guards remain mandatory because
   tag CI cannot prevent an already-pushed tag.
 
-## Stage 1: Add Build Version Resolution And `--version`
+## Stage 1: Add Build Version Resolution And `--version` ✅
 
 ### Goal
 

internal/buildinfo/buildinfo.go

@@ -0,0 +1,36 @@
+// Package buildinfo resolves the product version embedded in a Notarius build.
+package buildinfo
+
+import (
+	"fmt"
+	"regexp"
+	"runtime/debug"
+)
+
+var stableVersion = regexp.MustCompile(`^v(0|[1-9][0-9]*)\.(0|[1-9][0-9]*)\.(0|[1-9][0-9]*)$`)
+
+// Override is set at link time for controlled builds.
+var Override string
+
+// Version returns the release version embedded in the build, or development
+// when the build does not carry a stable release tag.
+func Version() (string, error) {
+	buildVersion := ""
+	if info, ok := debug.ReadBuildInfo(); ok {
+		buildVersion = info.Main.Version
+	}
+	return resolve(Override, buildVersion)
+}
+
+func resolve(override, buildVersion string) (string, error) {
+	if override != "" {
+		if !stableVersion.MatchString(override) {
+			return "", fmt.Errorf("build version override is not a stable release tag")
+		}
+		return override, nil
+	}
+	if stableVersion.MatchString(buildVersion) {
+		return buildVersion, nil
+	}
+	return "development", nil
+}

internal/buildinfo/buildinfo_test.go

@@ -0,0 +1,45 @@
+package buildinfo
+
+import "testing"
+
+func TestResolve(t *testing.T) {
+	tests := []struct {
+		name         string
+		override     string
+		buildVersion string
+		want         string
+		wantErr      bool
+	}{
+		{name: "stable main module version", buildVersion: "v1.2.3", want: "v1.2.3"},
+		{name: "zero version", buildVersion: "v0.0.0", want: "v0.0.0"},
+		{name: "override takes precedence", override: "v2.3.4", buildVersion: "v1.2.3", want: "v2.3.4"},
+		{name: "invalid override", override: "version", buildVersion: "v1.2.3", wantErr: true},
+		{name: "override with whitespace", override: " v1.2.3", wantErr: true},
+		{name: "leading zero major", buildVersion: "v01.2.3", want: "development"},
+		{name: "leading zero minor", buildVersion: "v1.02.3", want: "development"},
+		{name: "leading zero patch", buildVersion: "v1.2.03", want: "development"},
+		{name: "build version with whitespace", buildVersion: "v1.2.3 ", want: "development"},
+		{name: "prerelease", buildVersion: "v1.2.3-rc.1", want: "development"},
+		{name: "build suffix", buildVersion: "v1.2.3+build.1", want: "development"},
+		{name: "pseudo version", buildVersion: "v0.0.0-20260102030405-abcdef123456", want: "development"},
+		{name: "development build", buildVersion: "(devel)", want: "development"},
+		{name: "missing build information", want: "development"},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := resolve(tt.override, tt.buildVersion)
+			if tt.wantErr {
+				if err == nil {
+					t.Fatal("resolve() error = nil, want error")
+				}
+				return
+			}
+			if err != nil {
+				t.Fatalf("resolve() error = %v", err)
+			}
+			if got != tt.want {
+				t.Fatalf("resolve() = %q, want %q", got, tt.want)
+			}
+		})
+	}
+}

internal/cli/command_contract_test.go

@@ -8,6 +8,8 @@ import (
 	"path/filepath"
 	"strings"
 	"testing"
+
+	"gitea.maximumdirect.net/eric/notarius/internal/buildinfo"
 )
 
 func TestCommandHelpSpellingsWriteUsageToStdout(t *testing.T) {
@@ -38,6 +40,7 @@ func TestCommandSyntaxErrorsUseStderrAndExitTwo(t *testing.T) {
 		{name: "unknown pipelines subcommand", args: []string{"pipelines", "unknown"}, want: "unknown pipelines subcommand"},
 		{name: "malformed run flag", args: []string{"run", "demo", "--chunk_cache", "invalid"}, want: "not supported"},
 		{name: "unknown flag", args: []string{"config", "validate", "--unknown"}, want: "flag provided but not defined"},
+		{name: "version arguments", args: []string{"--version", "extra"}, want: "--version does not accept arguments"},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
@@ -50,6 +53,33 @@ func TestCommandSyntaxErrorsUseStderrAndExitTwo(t *testing.T) {
 	}
 }
 
+func TestCommandVersionOutput(t *testing.T) {
+	previous := buildinfo.Override
+	t.Cleanup(func() { buildinfo.Override = previous })
+
+	tests := []struct {
+		name       string
+		override   string
+		wantCode   int
+		wantStdout string
+		wantStderr string
+	}{
+		{name: "development", wantStdout: "notarius development\n"},
+		{name: "release override", override: "v1.2.3", wantStdout: "notarius v1.2.3\n"},
+		{name: "invalid override", override: "release", wantCode: 1, wantStderr: "notarius: build version override is not a stable release tag\n"},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			buildinfo.Override = tt.override
+			var stdout, stderr bytes.Buffer
+			code := RunWithOptions([]string{"--version"}, &stdout, &stderr, Options{})
+			if code != tt.wantCode || stdout.String() != tt.wantStdout || stderr.String() != tt.wantStderr {
+				t.Fatalf("code=%d stdout=%q stderr=%q", code, stdout.String(), stderr.String())
+			}
+		})
+	}
+}
+
 func TestConfigDiscoveryPrefersExplicitPathThenEnvironment(t *testing.T) {
 	explicit := writeCommandConfig(t, "explicit", "alpha")
 	environment := writeCommandConfig(t, "environment", "beta")

internal/cli/run.go

@@ -16,6 +16,7 @@ import (
 	"strings"
 	"time"
 
+	"gitea.maximumdirect.net/eric/notarius/internal/buildinfo"
 	"gitea.maximumdirect.net/eric/notarius/internal/core/artifacts"
 	"gitea.maximumdirect.net/eric/notarius/internal/core/config"
 	"gitea.maximumdirect.net/eric/notarius/internal/core/debugbundle"
@@ -31,6 +32,7 @@ import (
 const defaultConfigPath = "/usr/local/etc/notarius/config.yml"
 const usage = `Usage:
   notarius help
+  notarius --version
   notarius run <pipeline-id> --input path/to/source.json [--json] [flags]
   notarius config validate --config path/to/config.yml [--pipeline pipeline-id] [--only lane-a,lane-b]
   notarius pipelines list --config path/to/config.yml [--json]
@@ -62,6 +64,20 @@ func Run(args []string, stdout, stderr io.Writer) int {
 }
 
 func RunWithOptions(args []string, stdout, stderr io.Writer, opts Options) int {
+	if len(args) > 0 && args[0] == "--version" {
+		if len(args) != 1 {
+			fmt.Fprintln(stderr, "notarius: --version does not accept arguments")
+			return 2
+		}
+		version, err := buildinfo.Version()
+		if err != nil {
+			fmt.Fprintf(stderr, "notarius: %v\n", err)
+			return 1
+		}
+		fmt.Fprintf(stdout, "notarius %s\n", version)
+		return 0
+	}
+
 	var err error
 	opts, err = normalizeOptions(opts)
 	if err != nil {