CloudMigration - Display different error messages for create migration errors (#94683)

* start on tokens

* more error messages

* more handling

* rephrased with suggestions from Daniel

* separate gms parse method

* use translation

* refactor initial idea to use error obj

* use error dto result

* handle gms client

* clean logs and comments

* fix tests

* tests for gms

* test and lint

* lint

* one more handling from gms

* typing in fe

* use error interface

* use validation error

* remove unused gms error

* use errorlib and helper function in fe

* regen api

* use same error util

* one more error to handle

pkg/services/cloudmigration/gmsclient/gms_client_test.go

@@ -4,6 +4,7 @@ import (
 	"net/http"
 	"testing"
 
+	"github.com/grafana/grafana/pkg/services/cloudmigration"
 	"github.com/grafana/grafana/pkg/setting"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
@@ -65,3 +66,48 @@ func Test_buildBasePath(t *testing.T) {
 		})
 	}
 }
+
+func Test_handleGMSErrors(t *testing.T) {
+	t.Parallel()
+
+	c, err := NewGMSClient(&setting.Cfg{
+		CloudMigration: setting.CloudMigrationSettings{
+			GMSDomain: "http://some-domain:8080",
+		},
+	},
+		http.DefaultClient,
+	)
+	require.NoError(t, err)
+	client := c.(*gmsClientImpl)
+
+	testscases := []struct {
+		gmsResBody    []byte
+		expectedError error
+	}{
+		{
+			gmsResBody:    []byte(`{"message":"instance is unreachable, make sure the instance is running"}`),
+			expectedError: cloudmigration.ErrInstanceUnreachable,
+		},
+		{
+			gmsResBody:    []byte(`{"message":"checking if instance is reachable"}`),
+			expectedError: cloudmigration.ErrInstanceRequestError,
+		},
+		{
+			gmsResBody:    []byte(`{"message":"fetching instance by stack id 1234"}`),
+			expectedError: cloudmigration.ErrInstanceRequestError,
+		},
+		{
+			gmsResBody:    []byte(`{"status":"error","error":"authentication error: invalid token"}`),
+			expectedError: cloudmigration.ErrTokenValidationFailure,
+		},
+		{
+			gmsResBody:    []byte(""),
+			expectedError: cloudmigration.ErrTokenValidationFailure,
+		},
+	}
+
+	for _, tc := range testscases {
+		resError := client.handleGMSErrors(tc.gmsResBody)
+		require.ErrorIs(t, resError, tc.expectedError)
+	}
+}