cli: ensure 'acl auth-method update' doesn't deep merge the Config field (#7839)

agent/consul/authmethod/testauth/testing.go

@@ -81,7 +81,8 @@ func GetSessionToken(sessionID string, token string) (map[string]string, bool) {
 }
 
 type Config struct {
-	SessionID string // unique identifier for this set of tokens in the database
+	SessionID string            // unique identifier for this set of tokens in the database
+	Data      map[string]string `json:",omitempty"` // random data for testing
 
 	enterpriseConfig `mapstructure:",squash"`
 }

command/acl/authmethod/update/authmethod_update.go

@@ -253,6 +253,8 @@ func (c *cmd) Run(args []string) int {
 				c.UI.Error(fmt.Sprintf("Error loading configuration file: %v", err))
 				return 1
 			}
+			// Don't attempt a deep merge.
+			method.Config = make(map[string]interface{})
 			if err := json.Unmarshal([]byte(data), &method.Config); err != nil {
 				c.UI.Error(fmt.Sprintf("Error parsing JSON for auth method config: %v", err))
 				return 1

command/acl/authmethod/update/authmethod_update_test.go

@@ -100,15 +100,17 @@ func TestAuthMethodUpdateCommand(t *testing.T) {
 		return methodName
 	}
 
-	t.Run("update all fields", func(t *testing.T) {
-		name := createAuthMethod(t)
+	finalName := createAuthMethod(t)
 
+	t.Run("update all fields", func(t *testing.T) {
+		name := finalName
 		args := []string{
 			"-http-addr=" + a.HTTPAddr(),
 			"-token=root",
 			"-name=" + name,
 			"-display-name", "updated display",
 			"-description", "updated description",
+			"-config", `{ "SessionID": "foo" }`,
 		}
 
 		ui := cli.NewMockUi()
@@ -124,7 +126,42 @@ func TestAuthMethodUpdateCommand(t *testing.T) {
 			Type:        "testing",
 			DisplayName: "updated display",
 			Description: "updated description",
-			Config:      map[string]interface{}{},
+			Config: map[string]interface{}{
+				"SessionID": "foo",
+			},
+		}
+		require.Equal(t, expect, got)
+	})
+
+	t.Run("update config field and prove no merging happens", func(t *testing.T) {
+		name := finalName
+		args := []string{
+			"-http-addr=" + a.HTTPAddr(),
+			"-token=root",
+			"-name=" + name,
+			"-display-name", "updated display",
+			"-description", "updated description",
+			"-config", `{ "Data": { "foo": "bar"} }`,
+		}
+
+		ui := cli.NewMockUi()
+		cmd := New(ui)
+
+		code := cmd.Run(args)
+		require.Equal(t, code, 0)
+		require.Empty(t, ui.ErrorWriter.String())
+
+		got := getTestMethod(t, client, name)
+		expect := &api.ACLAuthMethod{
+			Name:        name,
+			Type:        "testing",
+			DisplayName: "updated display",
+			Description: "updated description",
+			Config: map[string]interface{}{
+				"Data": map[string]interface{}{
+					"foo": "bar",
+				},
+			},
 		}
 		require.Equal(t, expect, got)
 	})