Docker auth (nektos#891)

* feat: read docker credentials from local docker config

* fix: url.Parse requires protocol

Co-authored-by: Björn Brauer <zaubernerd@zaubernerd.de>

* fix: docker decides by the existence of . or : if...

... the image is in a custom registry or not.

Co-authored-by: Björn Brauer <zaubernerd@zaubernerd.de>

* fix: make docker hostname detection more robust

* test: mock docker config for getImagePullOptions test

By default github actions have a docker config set with a token to pull
images from docker hub.

Co-authored-by: Markus Wolf <markus.wolf@new-work.se>

Co-authored-by: Markus Wolf <markus.wolf@new-work.se>

go.sum

@@ -408,6 +408,7 @@ github.com/docker/docker v20.10.6+incompatible/go.mod h1:eEKB0N0r5NX/I1kEveEz05b
 github.com/docker/docker v20.10.7+incompatible/go.mod h1:eEKB0N0r5NX/I1kEveEz05bcu8tLC/8azJZsviup8Sk=
 github.com/docker/docker v20.10.10+incompatible h1:GKkP0T7U4ks6X3lmmHKC2QDprnpRJor2Z5a8m62R9ZM=
 github.com/docker/docker v20.10.10+incompatible/go.mod h1:eEKB0N0r5NX/I1kEveEz05bcu8tLC/8azJZsviup8Sk=
+github.com/docker/docker-credential-helpers v0.6.3 h1:zI2p9+1NQYdnG6sMU26EX4aVGlqbInSQxQXLvzJ4RPQ=
 github.com/docker/docker-credential-helpers v0.6.3/go.mod h1:WRaJzqw3CTB9bk10avuGsjVBZsD05qeibJ1/TYlvc0Y=
 github.com/docker/go-connections v0.4.0 h1:El9xVISelRB7BuFusrZozjnkIM5YnzCViNKohAFqRJQ=
 github.com/docker/go-connections v0.4.0/go.mod h1:Gbd7IOopHjR8Iph03tsViu4nIes5XhDvyHbTtUxmeec=

pkg/container/docker_auth.go

@@ -0,0 +1,36 @@
+package container
+
+import (
+	"strings"
+
+	"github.com/docker/cli/cli/config"
+	"github.com/docker/cli/cli/config/credentials"
+	"github.com/docker/docker/api/types"
+	log "github.com/sirupsen/logrus"
+)
+
+func LoadDockerAuthConfig(image string) (types.AuthConfig, error) {
+	config, err := config.Load(config.Dir())
+	if err != nil {
+		log.Warnf("Could not load docker config: %v", err)
+		return types.AuthConfig{}, err
+	}
+
+	if !config.ContainsAuth() {
+		config.CredentialsStore = credentials.DetectDefaultStore(config.CredentialsStore)
+	}
+
+	hostName := "index.docker.io"
+	index := strings.IndexRune(image, '/')
+	if index > -1 && (strings.ContainsAny(image[:index], ".:") || image[:index] == "localhost") {
+		hostName = image[:index]
+	}
+
+	authConfig, err := config.GetAuthConfig(hostName)
+	if err != nil {
+		log.Warnf("Could not get auth config from docker config: %v", err)
+		return types.AuthConfig{}, err
+	}
+
+	return types.AuthConfig(authConfig), nil
+}

pkg/container/docker_pull.go

@@ -77,6 +77,7 @@ func getImagePullOptions(ctx context.Context, input NewDockerPullExecutorInput)
 	imagePullOptions := types.ImagePullOptions{
 		Platform: input.Platform,
 	}
+
 	if input.Username != "" && input.Password != "" {
 		logger := common.Logger(ctx)
 		logger.Debugf("using authentication for docker pull")
@@ -91,6 +92,21 @@ func getImagePullOptions(ctx context.Context, input NewDockerPullExecutorInput)
 			return imagePullOptions, err
 		}
 
+		imagePullOptions.RegistryAuth = base64.URLEncoding.EncodeToString(encodedJSON)
+	} else {
+		authConfig, err := LoadDockerAuthConfig(input.Image)
+		if err != nil {
+			return imagePullOptions, err
+		}
+		if authConfig.Username == "" && authConfig.Password == "" {
+			return imagePullOptions, nil
+		}
+
+		encodedJSON, err := json.Marshal(authConfig)
+		if err != nil {
+			return imagePullOptions, err
+		}
+
 		imagePullOptions.RegistryAuth = base64.URLEncoding.EncodeToString(encodedJSON)
 	}
 

pkg/container/docker_pull_test.go

@@ -4,6 +4,8 @@ import (
 	"context"
 	"testing"
 
+	"github.com/docker/cli/cli/config"
+
 	log "github.com/sirupsen/logrus"
 	assert "github.com/stretchr/testify/assert"
 )
@@ -35,15 +37,25 @@ func TestCleanImage(t *testing.T) {
 func TestGetImagePullOptions(t *testing.T) {
 	ctx := context.Background()
 
+	config.SetDir("/non-existent/docker")
+
 	options, err := getImagePullOptions(ctx, NewDockerPullExecutorInput{})
 	assert.Nil(t, err, "Failed to create ImagePullOptions")
-	assert.Equal(t, options.RegistryAuth, "", "RegistryAuth should be empty if no username or password is set")
+	assert.Equal(t, "", options.RegistryAuth, "RegistryAuth should be empty if no username or password is set")
 
 	options, err = getImagePullOptions(ctx, NewDockerPullExecutorInput{
 		Image:    "",
 		Username: "username",
 		Password: "password",
 	})
 	assert.Nil(t, err, "Failed to create ImagePullOptions")
-	assert.Equal(t, options.RegistryAuth, "eyJ1c2VybmFtZSI6InVzZXJuYW1lIiwicGFzc3dvcmQiOiJwYXNzd29yZCJ9", "Username and Password should be provided")
+	assert.Equal(t, "eyJ1c2VybmFtZSI6InVzZXJuYW1lIiwicGFzc3dvcmQiOiJwYXNzd29yZCJ9", options.RegistryAuth, "Username and Password should be provided")
+
+	config.SetDir("testdata/docker-pull-options")
+
+	options, err = getImagePullOptions(ctx, NewDockerPullExecutorInput{
+		Image: "nektos/act",
+	})
+	assert.Nil(t, err, "Failed to create ImagePullOptions")
+	assert.Equal(t, "eyJ1c2VybmFtZSI6InVzZXJuYW1lIiwicGFzc3dvcmQiOiJwYXNzd29yZFxuIiwic2VydmVyYWRkcmVzcyI6Imh0dHBzOi8vaW5kZXguZG9ja2VyLmlvL3YxLyJ9", options.RegistryAuth, "RegistryAuth should be taken from local docker config")
 }

pkg/container/testdata/docker-pull-options/config.json

@@ -0,0 +1,7 @@
+{
+  "auths": {
+          "https://index.docker.io/v1/": {
+                  "auth": "dXNlcm5hbWU6cGFzc3dvcmQK"
+          }
+  }
+}