Add build flags

.dockerignore

@@ -0,0 +1,14 @@
+# Ignore files
+*.md
+*.sh
+*.yml
+*.yaml
+.gitignore
+
+# Ignore folders
+.github/
+.git/
+contrib/
+
+# Don't include a previously built binary
+unbound_exporter

.github/workflows/release.yml

@@ -23,7 +23,7 @@ jobs:
           persist-credentials: false
 
       - name: build binary
-        run: go build
+        run: go build -ldflags "-X github.com/letsencrypt/unbound_exporter/util.BuildID=$(git rev-parse --short HEAD) -X github.com/letsencrypt/unbound_exporter/util.BuildBranch=$(git rev-parse --abbrev-ref HEAD) -X github.com/letsencrypt/unbound_exporter/util.BuildTime=$(date +%F-%T -u)"
 
       - name: install nfpm
         run: go install github.com/goreleaser/nfpm/v2/cmd/[email protected]

Dockerfile

@@ -1,14 +1,9 @@
 FROM --platform=$BUILDPLATFORM docker.io/library/golang:1.21.4-bookworm AS build
 
-WORKDIR /go/src/app
-
-COPY go.mod .
-COPY go.sum .
+VOLUME . /go/src/app
 
 RUN go mod download
 
-COPY *.go .
-
 ENV CGO_ENABLED=0
 
 RUN GOOS=$TARGETOS GOARCH=$TARGETPLATFORM go build -v -o /go/bin/unbound_exporter ./...

build/vars.go

@@ -0,0 +1,28 @@
+package build
+
+const Unspecified = "Unspecified"
+
+// BuildID is set by the compiler (using -ldflags "-X util.BuildID $(git rev-parse --short HEAD)")
+// and is used by GetID
+var BuildID string
+
+// BuildBranch is set by the compiler and is used by GetBranch
+var BuildBranch string
+
+// GetBuildID identifies what build is running.
+func GetID() (BuildID string) {
+	if BuildID != "" {
+		return BuildID
+	}
+
+	return Unspecified
+}
+
+// GetBranch identifies the building host
+func GetBranch() (BuildBranch string) {
+	if BuildBranch != "" {
+		return BuildBranch
+	}
+
+	return Unspecified
+}

unbound_exporter.go

@@ -25,12 +25,14 @@ import (
 	"net/url"
 	"os"
 	"regexp"
+	"runtime"
 	"strconv"
 	"strings"
 
 	"sort"
 
 	"github.com/go-kit/log/level"
+	"github.com/letsencrypt/unbound_exporter/build"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"github.com/prometheus/common/promlog"
@@ -548,7 +550,10 @@ func main() {
 	)
 	flag.Parse()
 
-	_ = level.Info(log).Log("Starting unbound_exporter")
+	_ = level.Info(log).Log(
+		"msg", "Starting unbound_exporter",
+		"version", fmt.Sprintf("(version=%s, branch=%s, revision=%s)", runtime.Version(), build.GetBranch(), build.GetID()),
+	)
 	exporter, err := NewUnboundExporter(*unboundHost, *unboundCa, *unboundCert, *unboundKey)
 	if err != nil {
 		panic(err)