Read Go build info from the binary

Author: lucacome

.github/workflows/ci.yml

@@ -36,7 +36,6 @@ jobs:
     name: Checks and variables
     runs-on: ubuntu-20.04
     outputs:
-      sha: ${{ steps.vars.outputs.sha }}
       go_path: ${{ steps.vars.outputs.go_path }}
     steps:
       - name: Checkout Repository
@@ -49,7 +48,6 @@ jobs:
       - name: Output Variables
         id: vars
         run: |
-          echo "::set-output name=sha::$(echo ${GITHUB_SHA} | cut -c1-7)"
           echo "::set-output name=go_path::$(go env GOPATH)"
       - name: Check if go.mod and go.sum are up to date
         run: |
@@ -75,7 +73,7 @@ jobs:
       - name: Upload Coverage Report
         uses: actions/upload-artifact@v3
         with:
-          name: cover-${{ needs.vars.outputs.sha }}.html
+          name: cover-${{ github.run_id }}.html
           path: ${{ github.workspace }}/cover.html
         if: always()
 

.goreleaser.yml

@@ -14,6 +14,8 @@ builds:
       - all=-trimpath={{.Env.GOPATH}}
     asmflags:
       - all=-trimpath={{.Env.GOPATH}}
+    ldflags:
+      - -s -w -X main.version={{.Version}}
     main: ./cmd/gateway/
     binary: gateway
 

Makefile

@@ -2,9 +2,6 @@ VERSION = 0.0.1
 TAG = $(VERSION)
 PREFIX ?= nginx-kubernetes-gateway
 
-GIT_COMMIT = $(shell git rev-parse HEAD)
-DATE = $(shell date -u +"%Y-%m-%dT%H:%M:%SZ")
-
 TARGET ?= local
 
 KIND_KUBE_CONFIG_FOLDER = $${HOME}/.kube/kind
@@ -14,12 +11,12 @@ export DOCKER_BUILDKIT = 1
 
 .PHONY: container
 container: build
-	docker build --build-arg VERSION=$(VERSION) --build-arg GIT_COMMIT=$(GIT_COMMIT) --build-arg DATE=$(DATE) --target $(TARGET) -f build/Dockerfile -t $(PREFIX):$(TAG) .
+	docker build --build-arg VERSION=$(VERSION) --target $(TARGET) -f build/Dockerfile -t $(PREFIX):$(TAG) .
 
 .PHONY: build
 build:
 ifeq (${TARGET},local)
-	CGO_ENABLED=0 GOOS=linux go build -trimpath -a -ldflags "-s -w -X main.version=${VERSION} -X main.commit=${GIT_COMMIT} -X main.date=${DATE}" -o $(OUT_DIR)/gateway github.com/nginxinc/nginx-kubernetes-gateway/cmd/gateway
+	CGO_ENABLED=0 GOOS=linux go build -trimpath -a -ldflags "-s -w -X main.version=${VERSION}" -o $(OUT_DIR)/gateway github.com/nginxinc/nginx-kubernetes-gateway/cmd/gateway
 endif
 
 .PHONY: generate

build/Dockerfile

@@ -1,8 +1,6 @@
 # syntax=docker/dockerfile:1.4
 FROM golang:1.19 as builder
 ARG VERSION
-ARG GIT_COMMIT
-ARG DATE
 
 WORKDIR /go/src/github.com/nginxinc/nginx-kubernetes-gateway/cmd/gateway
 
@@ -12,7 +10,7 @@ RUN go mod download
 COPY cmd /go/src/github.com/nginxinc/nginx-kubernetes-gateway/cmd
 COPY internal /go/src/github.com/nginxinc/nginx-kubernetes-gateway/internal
 COPY pkg /go/src/github.com/nginxinc/nginx-kubernetes-gateway/pkg
-RUN CGO_ENABLED=0 GOOS=linux go build -trimpath -a -ldflags "-s -w -X main.version=${VERSION} -X main.commit=${GIT_COMMIT} -X main.date=${DATE}" -o gateway .
+RUN CGO_ENABLED=0 GOOS=linux go build -trimpath -a -ldflags "-s -w -X main.version=${VERSION}" -o gateway .
 
 FROM alpine:3.16 as capabilizer
 RUN apk add --no-cache libcap

cmd/gateway/main.go

@@ -18,8 +18,6 @@ const (
 var (
 	// Set during go build
 	version string
-	commit  string
-	date    string
 
 	// Command-line flags
 	gatewayCtlrName = flag.String(
@@ -50,9 +48,11 @@ func main() {
 		GatewayClassParam(),
 	)
 
+	commit, date, dirty := getBuildInfo()
 	logger.Info("Starting NGINX Kubernetes Gateway",
 		"version", version,
 		"commit", commit,
+		"dirty", dirty,
 		"date", date)
 
 	err := manager.Start(conf)

cmd/gateway/setup.go

@@ -4,6 +4,7 @@ import (
 	"errors"
 	"fmt"
 	"os"
+	"runtime/debug"
 	"strings"
 
 	flag "github.com/spf13/pflag"
@@ -14,11 +15,13 @@ const (
 	errTmpl = "failed validation - flag: '--%s' reason: '%s'\n"
 )
 
-type Validator func(*flag.FlagSet) error
-type ValidatorContext struct {
-	Key string
-	V   Validator
-}
+type (
+	Validator        func(*flag.FlagSet) error
+	ValidatorContext struct {
+		Key string
+		V   Validator
+	}
+)
 
 func GatewayControllerParam(domain string, namespace string) ValidatorContext {
 	name := "gateway-ctlr-name"
@@ -120,3 +123,26 @@ func MustValidateArguments(flagset *flag.FlagSet, validators ...ValidatorContext
 		os.Exit(1)
 	}
 }
+
+func getBuildInfo() (commitHash string, commitTime string, dirtyBuild bool) {
+	commitHash = "unknown"
+	commitTime = "unknown"
+	dirtyBuild = true
+
+	info, ok := debug.ReadBuildInfo()
+	if !ok {
+		return
+	}
+	for _, kv := range info.Settings {
+		switch kv.Key {
+		case "vcs.revision":
+			commitHash = kv.Value
+		case "vcs.time":
+			commitTime = kv.Value
+		case "vcs.modified":
+			dirtyBuild = kv.Value == "true"
+		}
+	}
+
+	return
+}