fix: improve CLI remote sourcing

cmd/client/grpc_client.go

@@ -2,6 +2,7 @@ package client
 
 import (
 	"context"
+	"fmt"
 	"os"
 	"time"
 
@@ -20,28 +21,25 @@ const (
 	EnvWriteRemote = "KETO_WRITE_REMOTE"
 )
 
-func getReadRemote(cmd *cobra.Command) string {
-	remote := flagx.MustGetString(cmd, FlagReadRemote)
-	if remote == "" {
-		remote = os.Getenv(EnvReadRemote)
+func getRemote(cmd *cobra.Command, flagRemote, envRemote string) string {
+	if cmd.Flags().Changed(flagRemote) {
+		return flagx.MustGetString(cmd, flagRemote)
+	} else if remote, isSet := os.LookupEnv(envRemote); isSet {
+		return remote
 	}
-	return remote
-}
 
-func getWriteRemote(cmd *cobra.Command) string {
-	remote := flagx.MustGetString(cmd, FlagWriteRemote)
-	if remote == "" {
-		remote = os.Getenv(EnvWriteRemote)
-	}
+	// no value is set, use fallback from the flag and warn about that
+	remote := flagx.MustGetString(cmd, flagRemote)
+	_, _ = fmt.Fprintf(cmd.ErrOrStderr(), "neither flag --%s nor env var %s are set, falling back to %s\n", flagRemote, envRemote, remote)
 	return remote
 }
 
 func GetReadConn(cmd *cobra.Command) (*grpc.ClientConn, error) {
-	return Conn(cmd.Context(), getReadRemote(cmd))
+	return Conn(cmd.Context(), getRemote(cmd, FlagReadRemote, EnvReadRemote))
 }
 
 func GetWriteConn(cmd *cobra.Command) (*grpc.ClientConn, error) {
-	return Conn(cmd.Context(), getWriteRemote(cmd))
+	return Conn(cmd.Context(), getRemote(cmd, FlagWriteRemote, EnvWriteRemote))
 }
 
 func Conn(ctx context.Context, remote string) (*grpc.ClientConn, error) {

cmd/client/grpc_client_test.go

@@ -0,0 +1,62 @@
+package client
+
+import (
+	"bytes"
+	"os"
+	"testing"
+
+	"github.com/spf13/cobra"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestGetRemote(t *testing.T) {
+	setup := func() (cmd *cobra.Command, stdOut, stdErr *bytes.Buffer) {
+		cmd = &cobra.Command{}
+		stdOut, stdErr = &bytes.Buffer{}, &bytes.Buffer{}
+		cmd.SetOut(stdOut)
+		cmd.SetErr(stdErr)
+		RegisterRemoteURLFlags(cmd.Flags())
+		return
+	}
+
+	setEnv := func(t *testing.T, env, val string) {
+		require.NoError(t, os.Setenv(env, val))
+		t.Cleanup(func() {
+			require.NoError(t, os.Unsetenv(EnvReadRemote))
+		})
+	}
+
+	t.Run("case=prefers flag value", func(t *testing.T) {
+		cmd, stdOut, stdErr := setup()
+
+		expectedRemote := "ketotest.oryapis.com"
+		require.NoError(t, cmd.Flags().Set(FlagReadRemote, "ketotest.oryapis.com"))
+		setEnv(t, EnvReadRemote, "not"+expectedRemote)
+
+		assert.Equal(t, expectedRemote, getRemote(cmd, FlagReadRemote, EnvReadRemote))
+		assert.Equal(t, 0, stdOut.Len())
+		assert.Equal(t, 0, stdErr.Len())
+	})
+
+	t.Run("case=uses env value", func(t *testing.T) {
+		cmd, stdOut, stdErr := setup()
+
+		expectedRemote := "ketotest.oryapis.com"
+		setEnv(t, EnvReadRemote, expectedRemote)
+
+		assert.Equal(t, expectedRemote, getRemote(cmd, FlagReadRemote, EnvReadRemote))
+		assert.Equal(t, 0, stdOut.Len())
+		assert.Equal(t, 0, stdErr.Len())
+	})
+
+	t.Run("case=falls back to flag default and prints warning", func(t *testing.T) {
+		cmd, stdOut, stdErr := setup()
+
+		expectedRemote := cmd.Flags().Lookup(FlagReadRemote).DefValue
+
+		assert.Equal(t, expectedRemote, getRemote(cmd, FlagReadRemote, EnvReadRemote))
+		assert.Equal(t, 0, stdOut.Len())
+		assert.Contains(t, stdErr.String(), "falling back")
+	})
+}