Fix flag loading order

Prior to this change, flags associated with the Config object were being
read too early (that is, before cobra had parsed them). They are now
read just in time for command execution.

Change-Id: I0affca9429867eb25db40f8323403e0f6976b47b

cmd/root.go

@@ -38,14 +38,15 @@ func NewRootCmd(out io.Writer) (*cobra.Command, *environment.AirshipCTLSettings,
 		SilenceUsage:  true,
 		PersistentPreRun: func(cmd *cobra.Command, args []string) {
 			log.Init(settings.Debug, cmd.OutOrStderr())
+
+			// Load or Initialize airship Config
+			settings.InitConfig()
 		},
 	}
 	rootCmd.SetOutput(out)
 	rootCmd.AddCommand(NewVersionCommand())
 
 	settings.InitFlags(rootCmd)
-	// Load or Initialize airship Config
-	settings.InitConfig()
 
 	return rootCmd, settings, nil
 }

cmd/root_test.go

@@ -1,9 +1,11 @@
 package cmd_test
 
 import (
+	"bytes"
 	"testing"
 
 	"github.com/spf13/cobra"
+	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
 	"opendev.org/airship/airshipctl/cmd"
@@ -36,6 +38,41 @@ func TestRoot(t *testing.T) {
 	}
 }
 
+func TestFlagLoading(t *testing.T) {
+	tests := []struct {
+		name     string
+		args     []string
+		expected string
+	}{
+		{
+			name:     "default, no flags",
+			args:     []string{},
+			expected: "$HOME/.airship/config",
+		},
+		{
+			name:     "alternate airshipconfig",
+			args:     []string{"--airshipconf", "/custom/path/to/airshipconfig"},
+			expected: "/custom/path/to/airshipconfig",
+		},
+	}
+
+	for _, tt := range tests {
+		tt := tt
+		t.Run(tt.name, func(subTest *testing.T) {
+			// We don't care about the output of this test, so toss
+			// it into a thowaway &bytes.buffer{}
+			rootCmd, settings, err := cmd.NewRootCmd(&bytes.Buffer{})
+			require.NoError(t, err)
+			rootCmd.SetArgs(tt.args)
+
+			err = rootCmd.Execute()
+			require.NoError(t, err)
+
+			assert.Equal(t, settings.AirshipConfigPath(), tt.expected)
+		})
+	}
+}
+
 func getVanillaRootCmd(t *testing.T) *cobra.Command {
 	t.Helper()
 	rootCmd, _, err := cmd.NewRootCmd(nil)