[ci] make it possible to use local copy of images

docs/images.md

@@ -0,0 +1,27 @@
+# Apoxy Images
+
+## Build Locally
+
+### Apoxy API Server
+
+```shell
+dagger call build-apiserver --src=. export --path=dist/images/apiserver.tar
+```
+
+To import the image into your local Docker daemon:
+
+```shell
+skopeo copy oci-archive:dist/images/apiserver.tar docker-daemon:docker.io/apoxy/apiserver:latest
+```
+
+### Apoxy Backplane
+
+```shell
+dagger call build-backplane --platform=linux/$(uname -m | sed 's/x86_64/amd64/;s/aarch64/arm64/') --src=. export --path=dist/images/backplane.tar
+```
+
+To import the image into your local Docker daemon:
+
+```shell
+skopeo copy oci-archive:dist/images/backplane.tar docker-daemon:docker.io/apoxy/backplane:latest
+```

pkg/backplane/drivers/docker.go

@@ -84,9 +84,12 @@ func (d *dockerDriver) Start(
 		return cname, nil
 	}
 
-	// Pull the image.
-	if err := exec.CommandContext(ctx, "docker", "pull", imageRef).Run(); err != nil {
-		return "", fmt.Errorf("failed to pull image %s: %w", imageRef, err)
+	// Check if we have the image.
+	if err := exec.CommandContext(ctx, "docker", "image", "inspect", imageRef).Run(); err != nil {
+		// If not, pull it.
+		if err := exec.CommandContext(ctx, "docker", "pull", imageRef).Run(); err != nil {
+			return "", fmt.Errorf("failed to pull image %s: %w", imageRef, err)
+		}
 	}
 
 	// Check for network and create if not exists.