Support podman auth file REGISTRY_AUTH_FILE.

pkg/authn/keychain.go

@@ -86,8 +86,8 @@ func (dk *defaultKeychain) Resolve(target Resource) (Authenticator, error) {
 	// config.Load, which may fail if the config can't be parsed.
 	//
 	// If neither was found, look for Podman's auth at
-	// $XDG_RUNTIME_DIR/containers/auth.json and attempt to load it as a
-	// Docker config.
+	// $REGISTRY_AUTH_FILE or $XDG_RUNTIME_DIR/containers/auth.json
+	// and attempt to load it as a Docker config.
 	//
 	// If neither are found, fallback to Anonymous.
 	var cf *configfile.ConfigFile
@@ -96,16 +96,28 @@ func (dk *defaultKeychain) Resolve(target Resource) (Authenticator, error) {
 		if err != nil {
 			return nil, err
 		}
-	} else {
+	} else if fileExists(os.Getenv("REGISTRY_AUTH_FILE")) {
+		f, err := os.Open(os.Getenv("REGISTRY_AUTH_FILE"))
+		if err != nil {
+			return nil, err
+		}
+		defer f.Close()
+		cf, err = config.LoadFromReader(f)
+		if err != nil {
+			return nil, err
+		}
+	} else if fileExists(filepath.Join(os.Getenv("XDG_RUNTIME_DIR"), "containers/auth.json")) {
 		f, err := os.Open(filepath.Join(os.Getenv("XDG_RUNTIME_DIR"), "containers/auth.json"))
 		if err != nil {
-			return Anonymous, nil
+			return nil, err
 		}
 		defer f.Close()
 		cf, err = config.LoadFromReader(f)
 		if err != nil {
 			return nil, err
 		}
+	} else {
+		return Anonymous, nil
 	}
 
 	// See:

pkg/authn/keychain_test.go

@@ -92,27 +92,31 @@ func TestNoConfig(t *testing.T) {
 	}
 }
 
+func writeConfig(t *testing.T, dir, file, content string) {
+	if err := os.MkdirAll(dir, 0777); err != nil {
+		t.Fatalf("mkdir %s: %v", dir, err)
+	}
+	if err := os.WriteFile(filepath.Join(dir, file), []byte(content), 0600); err != nil {
+		t.Fatalf("write %q: %v", file, err)
+	}
+}
+
 func TestPodmanConfig(t *testing.T) {
 	tmpdir := os.Getenv("TEST_TMPDIR")
 	if tmpdir == "" {
 		tmpdir = t.TempDir()
 	}
 	fresh++
-	p := filepath.Join(tmpdir, fmt.Sprintf("%d", fresh))
-	t.Setenv("XDG_RUNTIME_DIR", p)
-	os.Unsetenv("DOCKER_CONFIG")
-	if err := os.MkdirAll(filepath.Join(p, "containers"), 0777); err != nil {
-		t.Fatalf("mkdir %s/containers: %v", p, err)
-	}
-	cfg := filepath.Join(p, "containers/auth.json")
-	content := fmt.Sprintf(`{"auths": {"test.io": {"auth": %q}}}`, encode("foo", "bar"))
-	if err := os.WriteFile(cfg, []byte(content), 0600); err != nil {
-		t.Fatalf("write %q: %v", cfg, err)
-	}
 
+	os.Unsetenv("DOCKER_CONFIG")
 	// At first, $DOCKER_CONFIG is unset and $HOME/.docker/config.json isn't
-	// found, but Podman auth is configured. This should return Podman's
-	// auth.
+	// found, but Podman auth $XDG_RUNTIME_DIR/containers/auth.json is configured.
+	// This should return Podman's auth $XDG_RUNTIME_DIR/containers/auth.json.
+	p := filepath.Join(tmpdir, fmt.Sprintf("%d", fresh))
+	t.Setenv("XDG_RUNTIME_DIR", p)
+	writeConfig(t, filepath.Join(p, "containers"), "auth.json",
+		fmt.Sprintf(`{"auths": {"test.io": {"auth": %q}}}`,
+			encode("XDG_RUNTIME_DIR-foo", "XDG_RUNTIME_DIR-bar")))
 	auth, err := DefaultKeychain.Resolve(testRegistry)
 	if err != nil {
 		t.Fatalf("Resolve() = %v", err)
@@ -122,24 +126,40 @@ func TestPodmanConfig(t *testing.T) {
 		t.Fatal(err)
 	}
 	want := &AuthConfig{
-		Username: "foo",
-		Password: "bar",
+		Username: "XDG_RUNTIME_DIR-foo",
+		Password: "XDG_RUNTIME_DIR-bar",
 	}
 	if !reflect.DeepEqual(got, want) {
 		t.Errorf("got %+v, want %+v", got, want)
 	}
 
-	// Now, configure $HOME/.docker/config.json, which should override
-	// Podman auth and be used.
-	if err := os.MkdirAll(filepath.Join(os.Getenv("HOME"), ".docker"), 0777); err != nil {
-		t.Fatalf("mkdir $HOME/.docker: %v", err)
+	// Then, configure Podman auth $REGISTRY_AUTH_FILE.
+	// This demonstrates that $REGISTRY_AUTH_FILE is preferred over $XDG_RUNTIME_DIR/containers/auth.json.
+	t.Setenv("REGISTRY_AUTH_FILE", filepath.Join(p, "auth.json"))
+	writeConfig(t, p, "auth.json",
+		fmt.Sprintf(`{"auths": {"test.io": {"auth": %q}}}`,
+			encode("REGISTRY_AUTH_FILE-foo", "REGISTRY_AUTH_FILE-bar")))
+	auth, err = DefaultKeychain.Resolve(testRegistry)
+	if err != nil {
+		t.Fatalf("Resolve() = %v", err)
+	}
+	got, err = auth.Authorization()
+	if err != nil {
+		t.Fatal(err)
 	}
-	cfg = filepath.Join(os.Getenv("HOME"), ".docker/config.json")
-	content = fmt.Sprintf(`{"auths": {"test.io": {"auth": %q}}}`, encode("home-foo", "home-bar"))
-	if err := os.WriteFile(cfg, []byte(content), 0600); err != nil {
-		t.Fatalf("write %q: %v", cfg, err)
+	want = &AuthConfig{
+		Username: "REGISTRY_AUTH_FILE-foo",
+		Password: "REGISTRY_AUTH_FILE-bar",
+	}
+	if !reflect.DeepEqual(got, want) {
+		t.Errorf("got %+v, want %+v", got, want)
 	}
-	defer func() { os.Remove(cfg) }()
+
+	// Now, configure $HOME/.docker/config.json, which should override
+	// Podman auth and be used.
+	writeConfig(t, filepath.Join(os.Getenv("HOME"), ".docker"), "config.json",
+		fmt.Sprintf(`{"auths": {"test.io": {"auth": %q}}}`, encode("home-foo", "home-bar")))
+	defer func() { os.Remove(filepath.Join(os.Getenv("HOME"), ".docker/config.json")) }()
 	auth, err = DefaultKeychain.Resolve(testRegistry)
 	if err != nil {
 		t.Fatalf("Resolve() = %v", err)
@@ -160,7 +180,7 @@ func TestPodmanConfig(t *testing.T) {
 	// auth configured.
 	// This demonstrates that DOCKER_CONFIG is preferred over Podman auth
 	// and $HOME/.docker/config.json.
-	content = fmt.Sprintf(`{"auths": {"test.io": {"auth": %q}}}`, encode("another-foo", "another-bar"))
+	content := fmt.Sprintf(`{"auths": {"test.io": {"auth": %q}}}`, encode("another-foo", "another-bar"))
 	cd := setupConfigFile(t, content)
 	defer os.RemoveAll(filepath.Dir(cd))