Support ~/.config podman path in default keychain

pkg/authn/keychain.go

@@ -95,9 +95,13 @@ func (dk *defaultKeychain) ResolveContext(_ context.Context, target Resource) (A
 
 	// First, check $HOME/.docker/config.json
 	foundDockerConfig := false
+	configHome := os.Getenv("XDG_CONFIG_HOME")
 	home, err := homedir.Dir()
 	if err == nil {
 		foundDockerConfig = fileExists(filepath.Join(home, ".docker/config.json"))
+		if configHome == "" {
+			configHome = filepath.Join(home, ".config")
+		}
 	}
 	// If $HOME/.docker/config.json isn't found, check $DOCKER_CONFIG (if set)
 	if !foundDockerConfig && os.Getenv("DOCKER_CONFIG") != "" {
@@ -107,7 +111,8 @@ func (dk *defaultKeychain) ResolveContext(_ context.Context, target Resource) (A
 	// config.Load, which may fail if the config can't be parsed.
 	//
 	// If neither was found, look for Podman's auth at
-	// $REGISTRY_AUTH_FILE or $XDG_RUNTIME_DIR/containers/auth.json
+	// $REGISTRY_AUTH_FILE, $XDG_RUNTIME_DIR/containers/auth.json,
+	// $XDG_CONFIG_HOME/containers/auth.json, or ~/.config/containers/auth.json
 	// and attempt to load it as a Docker config.
 	//
 	// If neither are found, fallback to Anonymous.
@@ -137,6 +142,16 @@ func (dk *defaultKeychain) ResolveContext(_ context.Context, target Resource) (A
 		if err != nil {
 			return nil, err
 		}
+	} else if configHome != "" && fileExists(filepath.Join(configHome, "containers/auth.json")) {
+		f, err := os.Open(filepath.Join(configHome, "containers/auth.json"))
+		if err != nil {
+			return nil, err
+		}
+		defer f.Close()
+		cf, err = config.LoadFromReader(f)
+		if err != nil {
+			return nil, err
+		}
 	} else {
 		return Anonymous, nil
 	}

pkg/authn/keychain_test.go

@@ -110,13 +110,15 @@ func TestPodmanConfig(t *testing.T) {
 
 	os.Unsetenv("DOCKER_CONFIG")
 	// At first, $DOCKER_CONFIG is unset and $HOME/.docker/config.json isn't
-	// found, but Podman auth $XDG_RUNTIME_DIR/containers/auth.json is configured.
-	// This should return Podman's auth $XDG_RUNTIME_DIR/containers/auth.json.
+	// found, but Podman auth $XDG_CONFIG_HOME/containers/auth.json is configured.
+	// This should return Podman's auth $XDG_CONFIG_HOME/containers/auth.json.
+	// Note: on non-Linux platforms, $XDG_CONFIG_HOME usually won't be defined,
+	// and the path resolution should fall back to ~/.config in this case.
 	p := filepath.Join(tmpdir, fmt.Sprintf("%d", fresh))
-	t.Setenv("XDG_RUNTIME_DIR", p)
+	t.Setenv("XDG_CONFIG_HOME", 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")))
+			encode("XDG_CONFIG_HOME-foo", "XDG_CONFIG_HOME-bar")))
 	auth, err := DefaultKeychain.Resolve(testRegistry)
 	if err != nil {
 		t.Fatalf("Resolve() = %v", err)
@@ -126,6 +128,31 @@ func TestPodmanConfig(t *testing.T) {
 		t.Fatal(err)
 	}
 	want := &AuthConfig{
+		Username: "XDG_CONFIG_HOME-foo",
+		Password: "XDG_CONFIG_HOME-bar",
+	}
+	if !reflect.DeepEqual(got, want) {
+		t.Errorf("got %+v, want %+v", got, want)
+	}
+
+	// Then, configure $XDG_RUNTIME_DIR/containers/auth.json. This should take
+	// precedence over $XDG_CONFIG_HOME/containers/auth.json, as it does in
+	// podman.
+	fresh++
+	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)
+	}
+	got, err = auth.Authorization()
+	if err != nil {
+		t.Fatal(err)
+	}
+	want = &AuthConfig{
 		Username: "XDG_RUNTIME_DIR-foo",
 		Password: "XDG_RUNTIME_DIR-bar",
 	}