Stop auth commands from modifying global config file (#5378)

internal/authflow/flow.go

@@ -26,6 +26,7 @@ var (
 type iconfig interface {
 	Set(string, string, string) error
 	Write() error
+	WriteHosts() error
 }
 
 func AuthFlowWithConfig(cfg iconfig, IO *iostreams.IOStreams, hostname, notice string, additionalScopes []string, isInteractive bool) (string, error) {
@@ -46,7 +47,7 @@ func AuthFlowWithConfig(cfg iconfig, IO *iostreams.IOStreams, hostname, notice s
 		return "", err
 	}
 
-	return token, cfg.Write()
+	return token, cfg.WriteHosts()
 }
 
 func authFlow(oauthHost string, IO *iostreams.IOStreams, notice string, additionalScopes []string, isInteractive bool) (string, string, error) {

internal/config/config_file_test.go

@@ -9,6 +9,7 @@ import (
 	"runtime"
 	"testing"
 
+	"github.com/MakeNowJust/heredoc"
 	"github.com/stretchr/testify/assert"
 	"gopkg.in/yaml.v3"
 )
@@ -269,6 +270,31 @@ func Test_configFile_Write_toDisk(t *testing.T) {
 	}
 }
 
+func Test_configFile_WriteHosts_toDisk(t *testing.T) {
+	configDir := filepath.Join(t.TempDir(), ".config", "gh")
+	_ = os.MkdirAll(configDir, 0755)
+	os.Setenv(GH_CONFIG_DIR, configDir)
+	defer os.Unsetenv(GH_CONFIG_DIR)
+
+	cfg := NewFromString(heredoc.Doc(`
+    hosts:
+      github.com:
+        user: monalisa
+        oauth_token: TOKEN
+		`))
+	err := cfg.WriteHosts()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	expectedConfig := "github.com:\n    user: monalisa\n    oauth_token: TOKEN\n"
+	actualConfig, err := ioutil.ReadFile(filepath.Join(configDir, "hosts.yml"))
+	assert.NoError(t, err)
+	assert.Equal(t, expectedConfig, string(actualConfig))
+	_, nonExistErr := os.Stat(filepath.Join(configDir, "config.yml"))
+	assert.Error(t, nonExistErr)
+}
+
 func Test_autoMigrateConfigDir_noMigration_notExist(t *testing.T) {
 	homeDir := t.TempDir()
 	migrateDir := t.TempDir()

internal/config/config_type.go

@@ -21,6 +21,7 @@ type Config interface {
 	Aliases() (*AliasConfig, error)
 	CheckWriteable(string, string) error
 	Write() error
+	WriteHosts() error
 }
 
 type ConfigOption struct {

internal/config/from_file.go

@@ -135,13 +135,10 @@ func (c *fileConfig) CheckWriteable(hostname, key string) error {
 
 func (c *fileConfig) Write() error {
 	mainData := yaml.Node{Kind: yaml.MappingNode}
-	hostsData := yaml.Node{Kind: yaml.MappingNode}
 
 	nodes := c.documentRoot.Content[0].Content
 	for i := 0; i < len(nodes)-1; i += 2 {
-		if nodes[i].Value == "hosts" {
-			hostsData.Content = append(hostsData.Content, nodes[i+1].Content...)
-		} else {
+		if nodes[i].Value != "hosts" {
 			mainData.Content = append(mainData.Content, nodes[i], nodes[i+1])
 		}
 	}
@@ -151,12 +148,26 @@ func (c *fileConfig) Write() error {
 		return err
 	}
 
-	filename := ConfigFile()
-	err = WriteConfigFile(filename, yamlNormalize(mainBytes))
+	err = WriteConfigFile(ConfigFile(), yamlNormalize(mainBytes))
 	if err != nil {
 		return err
 	}
 
+	return c.WriteHosts()
+}
+
+// Write the hosts config file only, so as to allow logging in when the main
+// config file is not writable.
+func (c *fileConfig) WriteHosts() error {
+	hostsData := yaml.Node{Kind: yaml.MappingNode}
+
+	nodes := c.documentRoot.Content[0].Content
+	for i := 0; i < len(nodes)-1; i += 2 {
+		if nodes[i].Value == "hosts" {
+			hostsData.Content = append(hostsData.Content, nodes[i+1].Content...)
+		}
+	}
+
 	hostsBytes, err := yaml.Marshal(&hostsData)
 	if err != nil {
 		return err

internal/config/stub.go

@@ -67,6 +67,10 @@ func (c ConfigStub) Write() error {
 	return nil
 }
 
+func (c ConfigStub) WriteHosts() error {
+	return nil
+}
+
 func (c ConfigStub) DefaultHost() (string, error) {
 	return "", nil
 }

pkg/cmd/auth/login/login.go

@@ -161,7 +161,7 @@ func loginRun(opts *LoginOptions) error {
 			return fmt.Errorf("error validating token: %w", err)
 		}
 
-		return cfg.Write()
+		return cfg.WriteHosts()
 	}
 
 	existingToken, _ := cfg.Get(hostname, "oauth_token")

pkg/cmd/auth/logout/logout.go

@@ -151,7 +151,7 @@ func logoutRun(opts *LogoutOptions) error {
 	}
 
 	cfg.UnsetHost(hostname)
-	err = cfg.Write()
+	err = cfg.WriteHosts()
 	if err != nil {
 		return fmt.Errorf("failed to write config, authentication configuration not updated: %w", err)
 	}

pkg/cmd/auth/shared/login_flow.go

@@ -18,6 +18,7 @@ type iconfig interface {
 	Get(string, string) (string, error)
 	Set(string, string, string) error
 	Write() error
+	WriteHosts() error
 }
 
 type LoginOptions struct {
@@ -173,7 +174,7 @@ func Login(opts *LoginOptions) error {
 		fmt.Fprintf(opts.IO.ErrOut, "%s Configured git protocol\n", cs.SuccessIcon())
 	}
 
-	err := cfg.Write()
+	err := cfg.WriteHosts()
 	if err != nil {
 		return err
 	}

pkg/cmd/auth/shared/login_flow_test.go

@@ -30,6 +30,10 @@ func (c tinyConfig) Write() error {
 	return nil
 }
 
+func (c tinyConfig) WriteHosts() error {
+	return nil
+}
+
 func TestLogin_ssh(t *testing.T) {
 	dir := t.TempDir()
 	io, _, stdout, stderr := iostreams.Test()