fulcio: add version command

Makefile

@@ -26,6 +26,25 @@ TOOLS_DIR := hack/tools
 TOOLS_BIN_DIR := $(abspath $(TOOLS_DIR)/bin)
 BIN_DIR := $(abspath $(ROOT_DIR)/bin)
 
+# Set version variables for LDFLAGS
+GIT_VERSION ?= $(shell git describe --tags --always --dirty)
+GIT_HASH ?= $(shell git rev-parse HEAD)
+DATE_FMT = +'%Y-%m-%dT%H:%M:%SZ'
+SOURCE_DATE_EPOCH ?= $(shell git log -1 --pretty=%ct)
+ifdef SOURCE_DATE_EPOCH
+    BUILD_DATE ?= $(shell date -u -d "@$(SOURCE_DATE_EPOCH)" "$(DATE_FMT)" 2>/dev/null || date -u -r "$(SOURCE_DATE_EPOCH)" "$(DATE_FMT)" 2>/dev/null || date -u "$(DATE_FMT)")
+else
+    BUILD_DATE ?= $(shell date "$(DATE_FMT)")
+endif
+GIT_TREESTATE = "clean"
+DIFF = $(shell git diff --quiet >/dev/null 2>&1; if [ $$? -eq 1 ]; then echo "1"; fi)
+ifeq ($(DIFF), 1)
+    GIT_TREESTATE = "dirty"
+endif
+
+SERVER_PKG=github.com/sigstore/fulcio/cmd/app
+SERVER_LDFLAGS="-X $(SERVER_PKG).gitVersion=$(GIT_VERSION) -X $(SERVER_PKG).gitCommit=$(GIT_HASH) -X $(SERVER_PKG).gitTreeState=$(GIT_TREESTATE) -X $(SERVER_PKG).buildDate=$(BUILD_DATE)"
+
 # Binaries
 SWAGGER := $(TOOLS_BIN_DIR)/swagger
 
@@ -43,7 +62,7 @@ gosec:
 	$(GOBIN)/gosec ./...
 
 fulcio: $(SRCS)
-	go build
+	go build -ldflags $(SERVER_LDFLAGS)
 
 test:
 	go test ./...

cmd/app/version.go

@@ -0,0 +1,131 @@
+//
+// Copyright 2021 The Sigstore Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package app
+
+import (
+	"encoding/json"
+	"fmt"
+	"runtime"
+	"strings"
+	"text/tabwriter"
+
+	"github.com/pkg/errors"
+	"github.com/spf13/cobra"
+)
+
+// Base version information.
+//
+// This is the fallback data used when version information from git is not
+// provided via go ldflags (e.g. via Makefile).
+var (
+	// Output of "git describe". The prerequisite is that the branch should be
+	// tagged using the correct versioning strategy.
+	gitVersion = "unknown"
+	// SHA1 from git, output of $(git rev-parse HEAD)
+	gitCommit = "unknown"
+	// State of git tree, either "clean" or "dirty"
+	gitTreeState = "unknown"
+	// Build date in ISO8601 format, output of $(date -u +'%Y-%m-%dT%H:%M:%SZ')
+	buildDate = "unknown"
+)
+
+type versionOptions struct {
+	json bool
+}
+
+var versionOpts = &versionOptions{}
+
+// verifyCmd represents the verify command
+var versionCmd = &cobra.Command{
+	Use:   "version",
+	Short: "fulcio-server version",
+	RunE: func(cmd *cobra.Command, args []string) error {
+		return runVersion(versionOpts)
+	},
+}
+
+func init() {
+	versionCmd.PersistentFlags().BoolVarP(&versionOpts.json, "json", "j", false,
+		"print JSON instead of text")
+	rootCmd.AddCommand(versionCmd)
+}
+
+func runVersion(opts *versionOptions) error {
+	v := VersionInfo()
+	res := v.String()
+
+	if opts.json {
+		j, err := v.JSONString()
+		if err != nil {
+			return errors.Wrap(err, "unable to generate JSON from version info")
+		}
+		res = j
+	}
+
+	fmt.Println(res)
+	return nil
+}
+
+type Info struct {
+	GitVersion   string
+	GitCommit    string
+	GitTreeState string
+	BuildDate    string
+	GoVersion    string
+	Compiler     string
+	Platform     string
+}
+
+func VersionInfo() Info {
+	// These variables typically come from -ldflags settings and in
+	// their absence fallback to the global defaults set above.
+	return Info{
+		GitVersion:   gitVersion,
+		GitCommit:    gitCommit,
+		GitTreeState: gitTreeState,
+		BuildDate:    buildDate,
+		GoVersion:    runtime.Version(),
+		Compiler:     runtime.Compiler,
+		Platform:     fmt.Sprintf("%s/%s", runtime.GOOS, runtime.GOARCH),
+	}
+}
+
+// String returns the string representation of the version info
+func (i *Info) String() string {
+	b := strings.Builder{}
+	w := tabwriter.NewWriter(&b, 0, 0, 2, ' ', 0)
+
+	fmt.Fprintf(w, "GitVersion:\t%s\n", i.GitVersion)
+	fmt.Fprintf(w, "GitCommit:\t%s\n", i.GitCommit)
+	fmt.Fprintf(w, "GitTreeState:\t%s\n", i.GitTreeState)
+	fmt.Fprintf(w, "BuildDate:\t%s\n", i.BuildDate)
+	fmt.Fprintf(w, "GoVersion:\t%s\n", i.GoVersion)
+	fmt.Fprintf(w, "Compiler:\t%s\n", i.Compiler)
+	fmt.Fprintf(w, "Platform:\t%s\n", i.Platform)
+
+	w.Flush() // #nosec
+	return b.String()
+}
+
+// JSONString returns the JSON representation of the version info
+func (i *Info) JSONString() (string, error) {
+	b, err := json.MarshalIndent(i, "", "  ")
+	if err != nil {
+		return "", err
+	}
+
+	return string(b), nil
+}

go.mod

@@ -23,6 +23,7 @@ require (
 	github.com/mailru/easyjson v0.7.7 // indirect
 	github.com/miekg/pkcs11 v1.0.3 // indirect
 	github.com/mitchellh/mapstructure v1.4.1
+	github.com/pkg/errors v0.9.1
 	github.com/prometheus/client_golang v1.11.0
 	github.com/prometheus/common v0.29.0 // indirect
 	github.com/prometheus/procfs v0.7.0 // indirect