From ccd6858c1225e39b66d1872641e07f1ef8a1d4e2 Mon Sep 17 00:00:00 2001
From: Julien Vey <vey.julien@gmail.com>
Date: Wed, 22 Dec 2021 00:34:39 +0100
Subject: [PATCH] feat: Add labels on image build

---
 builder/docker/builder.go | 29 ++++++++++++++++++++++-
 dag/image.go              | 50 +++++++++++++++++++++++++++++++++++----
 types/types.go            | 10 ++++++++
 3 files changed, 84 insertions(+), 5 deletions(-)

diff --git a/builder/docker/builder.go b/builder/docker/builder.go
index 828fc810..8bafe8c0 100644
--- a/builder/docker/builder.go
+++ b/builder/docker/builder.go
@@ -1,6 +1,9 @@
 package docker
 
 import (
+	"fmt"
+	"time"
+
 	"github.com/radiofrance/dib/exec"
 	"github.com/radiofrance/dib/types"
 	"github.com/sirupsen/logrus"
@@ -25,8 +28,32 @@ func (b ImageBuilder) Build(opts types.ImageBuilderOpts) error {
 		logrus.Infof("[DRY-RUN] docker push %s", opts.Tag)
 		return nil
 	}
+	dockerArgs := []string{
+		"build",
+		"--no-cache",
+		"--pull",
+	}
+
+	if opts.CreationTime != nil {
+		dockerArgs = append(dockerArgs, "--label", fmt.Sprintf("org.opencontainers.image.created=%s",
+			opts.CreationTime.Format(time.RFC3339)))
+	}
+	if opts.Authors != nil {
+		dockerArgs = append(dockerArgs, "--label", fmt.Sprintf("org.opencontainers.image.authors=%s",
+			*opts.Authors))
+	}
+	if opts.Source != nil {
+		dockerArgs = append(dockerArgs, "--label", fmt.Sprintf("org.opencontainers.image.source=%s",
+			*opts.Source))
+	}
+	if opts.Revision != nil {
+		dockerArgs = append(dockerArgs, "--label", fmt.Sprintf("org.opencontainers.image.revision=%s",
+			*opts.Revision))
+	}
+
+	dockerArgs = append(dockerArgs, "-t", opts.Tag, opts.Context)
 
-	err := b.exec.ExecuteStdout("docker", "build", "--no-cache", "--pull", "-t", opts.Tag, opts.Context)
+	err := b.exec.ExecuteStdout("docker", dockerArgs...)
 	if err != nil {
 		return err
 	}
diff --git a/dag/image.go b/dag/image.go
index 5cfb9105..749f4acd 100644
--- a/dag/image.go
+++ b/dag/image.go
@@ -2,8 +2,10 @@ package dag
 
 import (
 	"fmt"
+	"os"
 	"strings"
 	"sync"
+	"time"
 
 	"github.com/radiofrance/dib/types"
 
@@ -100,10 +102,23 @@ func (img *Image) doRebuild(newTag string) error {
 		return err
 	}
 
-	err := img.Builder.Build(types.ImageBuilderOpts{
-		Context: img.Dockerfile.ContextPath,
-		Tag:     fmt.Sprintf("%s:%s", img.Name, newTag),
-	})
+	now := time.Now()
+	opts := types.ImageBuilderOpts{
+		Context:      img.Dockerfile.ContextPath,
+		Tag:          fmt.Sprintf("%s:%s", img.Name, newTag),
+		CreationTime: &now,
+	}
+	if rev := findRevision(); rev != "" {
+		opts.Revision = &rev
+	}
+	if authors := findAuthors(); authors != "" {
+		opts.Authors = &authors
+	}
+	if source := findSource(); source != "" {
+		opts.Authors = &source
+	}
+
+	err := img.Builder.Build(opts)
 	if err != nil {
 		return err
 	}
@@ -115,6 +130,33 @@ func (img *Image) doRebuild(newTag string) error {
 	return nil
 }
 
+func findSource() string {
+	if url := os.Getenv("CI_PROJECT_URL"); url != "" { // gitlab predefined variable
+		return url
+	} else if url := os.Getenv("GITHUB_REPOSITORY"); url != "" { // github predefined variable
+		return fmt.Sprintf("https://github.com/%s", url)
+	}
+	return ""
+}
+
+func findAuthors() string {
+	if authors := os.Getenv("GITLAB_USER_NAME"); authors != "" { // gitlab predefined variable
+		return authors
+	} else if authors := os.Getenv("GITHUB_ACTOR"); authors != "" { // github predefined variable
+		return authors
+	}
+	return ""
+}
+
+func findRevision() string {
+	if rev := os.Getenv("CI_COMMIT_SHA"); rev != "" { // gitlab predefined variable
+		return rev
+	} else if rev := os.Getenv("GITHUB_SHA"); rev != "" { // github predefined variable
+		return rev
+	}
+	return ""
+}
+
 // runTests run docker tests for each TestRunner.
 func (img *Image) runTests(ref, path string) error {
 	rateLimit <- struct{}{}
diff --git a/types/types.go b/types/types.go
index d6c51ddd..4fc00a57 100644
--- a/types/types.go
+++ b/types/types.go
@@ -1,5 +1,7 @@
 package types
 
+import "time"
+
 // ImageBuilder is the interface for building Docker images.
 type ImageBuilder interface {
 	Build(opts ImageBuilderOpts) error
@@ -11,6 +13,14 @@ type ImageBuilderOpts struct {
 	Context string
 	// Name of the tag to build, same as passed to the '-t' flag of the docker build command.
 	Tag string
+	// Date and time on which the image was built (string, date-time as defined by RFC 3339).
+	CreationTime *time.Time
+	// Contact details of the people or organization responsible for the image (freeform string)
+	Authors *string
+	// URL to get source code for building the image (string)
+	Source *string
+	// Source control revision identifier for the packaged software.
+	Revision *string
 }
 
 // TestRunner is an interface for dealing with docker tests, such as dgoss, trivy.