feat(kubectl-trace): support version for image version

Signed-off-by: Lorenzo Fontana <lo@linux.com>

Makefile

@@ -13,17 +13,19 @@ IMAGE_BPFTRACE_COMMIT := quay.io/fntlnz/kubectl-trace-bpftrace:$(GIT_COMMIT)
 
 IMAGE_BUILD_FLAGS ?= "--no-cache"
 
+LDFLAGS := -ldflags '-X github.com/fntlnz/kubectl-trace/pkg/version.buildTime=$(shell date +%s) -X github.com/fntlnz/kubectl-trace/pkg/version.gitCommit=${GIT_COMMIT}'
+
 kubectl_trace ?= _output/bin/kubectl-trace
 trace_runner ?= _output/bin/trace-runner
 
 .PHONY: build
 build: clean ${kubectl_trace} ${trace_runner}
 
 ${kubectl_trace}:
-	CGO_ENABLED=0 $(GO) build -o $@ ./cmd/kubectl-trace
+	CGO_ENABLED=1 $(GO) build ${LDFLAGS} -o $@ ./cmd/kubectl-trace
 
 ${trace_runner}:
-	CGO_ENABLED=1 $(GO) build -o $@ ./cmd/trace-runner
+	CGO_ENABLED=1 $(GO) build ${LDFLAGS} -o $@ ./cmd/trace-runner
 
 .PHONY: clean
 clean:

cmd/kubectl-trace/root.go

@@ -18,6 +18,7 @@ func main() {
 		Out:    os.Stdout,
 		ErrOut: os.Stderr,
 	}
+
 	root := cmd.NewTraceCommand(streams)
 	if err := root.Execute(); err != nil {
 		os.Exit(1)

pkg/cmd/trace.go

@@ -73,6 +73,7 @@ func NewTraceCommand(streams genericclioptions.IOStreams) *cobra.Command {
 	cmd.AddCommand(NewGetCommand(f, streams))
 	cmd.AddCommand(NewAttachCommand(f, streams))
 	cmd.AddCommand(NewDeleteCommand(f, streams))
+	cmd.AddCommand(NewVersionCommand(streams))
 
 	return cmd
 }

pkg/cmd/version.go

@@ -0,0 +1,21 @@
+package cmd
+
+import (
+	"fmt"
+
+	"github.com/fntlnz/kubectl-trace/pkg/version"
+	"github.com/spf13/cobra"
+	"k8s.io/cli-runtime/pkg/genericclioptions"
+)
+
+func NewVersionCommand(streams genericclioptions.IOStreams) *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "version",
+		Short: "Print the version information for kubectl trace",
+		RunE: func(c *cobra.Command, args []string) error {
+			fmt.Fprintln(streams.Out, version.String())
+			return nil
+		},
+	}
+	return cmd
+}

pkg/tracejob/job.go

@@ -3,6 +3,8 @@ package tracejob
 import (
 	"fmt"
 
+	"github.com/fntlnz/kubectl-trace/pkg/version"
+
 	"io"
 	"io/ioutil"
 
@@ -248,7 +250,7 @@ func (t *TraceJobClient) CreateJob(nj TraceJob) (*batchv1.Job, error) {
 					Containers: []apiv1.Container{
 						apiv1.Container{
 							Name:    nj.Name,
-							Image:   "quay.io/fntlnz/kubectl-trace-bpftrace:feature-pod-support-tracerunner", //TODO(fntlnz): yes this should be configurable!
+							Image:   version.ImageNameTag(),
 							Command: bpfTraceCmd,
 							TTY:     true,
 							Stdin:   true,

pkg/version/version.go

@@ -0,0 +1,41 @@
+package version
+
+import (
+	"fmt"
+	"strconv"
+	"time"
+)
+
+// Populated by makefile
+var gitCommit string
+var buildTime string
+var versionFormat = "git commit: %s\nbuild date: %s"
+var imageNameTagFormat = "quay.io/fntlnz/kubectl-trace-bpftrace:%s"
+
+func GitCommit() string {
+	return gitCommit
+}
+
+func ImageNameTag() string {
+	return fmt.Sprintf(imageNameTagFormat, GitCommit())
+}
+
+func Time() *time.Time {
+	if len(buildTime) == 0 {
+		return nil
+	}
+	i, err := strconv.ParseInt(buildTime, 10, 64)
+	if err != nil {
+		return nil
+	}
+	t := time.Unix(i, 0)
+	return &t
+}
+
+func String() string {
+	ts := Time()
+	if ts == nil {
+		return fmt.Sprintf(versionFormat, GitCommit(), "undefined")
+	}
+	return fmt.Sprintf(versionFormat, GitCommit(), ts.String())
+}