Merge "Refactor management of config file paths"

pkg/config/config.go

@@ -29,21 +29,20 @@ import (
 	"sigs.k8s.io/yaml"
 
 	"k8s.io/client-go/tools/clientcmd"
-
+	clientcmdapi "k8s.io/client-go/tools/clientcmd/api"
-	kubeconfig "k8s.io/client-go/tools/clientcmd/api"
 
 	"opendev.org/airship/airshipctl/pkg/util"
 )
 
-// Called from root to Load the initial configuration
+// LoadConfig populates the Config object using the files found at
-func (c *Config) LoadConfig(configFileArg string, kPathOptions *clientcmd.PathOptions) error {
+// airshipConfigPath and kubeConfigPath
-	err := c.loadFromAirConfig(configFileArg)
+func (c *Config) LoadConfig(airshipConfigPath, kubeConfigPath string) error {
+	err := c.loadFromAirConfig(airshipConfigPath)
 	if err != nil {
 		return err
 	}
 
-	// Load or initialize the kubeconfig object from a file
+	err = c.loadKubeConfig(kubeConfigPath)
-	err = c.loadKubeConfig(kPathOptions)
 	if err != nil {
 		return err
 	}
@@ -52,36 +51,45 @@ func (c *Config) LoadConfig(configFileArg string, kPathOptions *clientcmd.PathOp
 	return c.reconcileConfig()
 }
 
-func (c *Config) loadFromAirConfig(configFileArg string) error {
+// loadFromAirConfig populates the Config from the file found at airshipConfigPath.
-	// If it exists,  Read the ConfigFile data
+// If there is no file at airshipConfigPath, this function does nothing.
-	// Only care about the errors here, because there is a file
+// An error is returned if:
-	// And essentially I cannot use its data.
+// * airshipConfigPath is the empty string
-	// airshipctl probable should stop
+// * the file at airshipConfigPath is inaccessible
-	if configFileArg == "" {
+// * the file at airshipConfigPath cannot be marshaled into Config
+func (c *Config) loadFromAirConfig(airshipConfigPath string) error {
+	if airshipConfigPath == "" {
 		return errors.New("Configuration file location was not provided.")
 	}
+
 	// Remember where I loaded the Config from
-	c.loadedConfigPath = configFileArg
+	c.loadedConfigPath = airshipConfigPath
-	// If I have a file to read, load from it
 
-	if _, err := os.Stat(configFileArg); os.IsNotExist(err) {
+	// If I can read from the file, load from it
+	if _, err := os.Stat(airshipConfigPath); os.IsNotExist(err) {
 		return nil
-	}
+	} else if err != nil {
-	return util.ReadYAMLFile(configFileArg, c)
-}
-
-func (c *Config) loadKubeConfig(kPathOptions *clientcmd.PathOptions) error {
-	// Will need this for Persisting the changes
-	c.loadedPathOptions = kPathOptions
-	// Now at this point what I load might not reflect the associated kubeconfig yet
-	kConfig, err := kPathOptions.GetStartingConfig()
-	if err != nil {
 		return err
 	}
-	// Store the kubeconfig object into an airship managed kubeconfig object
-	c.kubeConfig = kConfig
 
-	return nil
+	return util.ReadYAMLFile(airshipConfigPath, c)
+}
+
+func (c *Config) loadKubeConfig(kubeConfigPath string) error {
+	// Will need this for persisting the changes
+	c.kubeConfigPath = kubeConfigPath
+
+	// If I can read from the file, load from it
+	var err error
+	if _, err = os.Stat(kubeConfigPath); os.IsNotExist(err) {
+		c.kubeConfig = clientcmdapi.NewConfig()
+		return nil
+	} else if err != nil {
+		return err
+	}
+
+	c.kubeConfig, err = clientcmd.LoadFromFile(kubeConfigPath)
+	return err
 }
 
 // reconcileConfig serves two functions:
@@ -198,6 +206,7 @@ func (c *Config) rmConfigClusterStragglers(persistIt bool) bool {
 	}
 	return rccs
 }
+
 func (c *Config) reconcileContexts(updatedClusterNames map[string]string) {
 	for key, context := range c.kubeConfig.Contexts {
 		// Check if the Cluster name referred to by the context
@@ -254,7 +263,7 @@ func (c *Config) reconcileAuthInfos() {
 func (c *Config) reconcileCurrentContext() {
 	// If the Airship current context is different that the current context in the kubeconfig
 	// then
-	//  - if the airship current context is valid, then updated kubeconfiug CC
+	//  - if the airship current context is valid, then updated kubeconfig CC
 	//  - if the airship currentcontext is invalid, and the kubeconfig CC is valid, then create the reference
 	//  - otherwise , they are both empty. Make sure
 
@@ -326,20 +335,17 @@ func (c *Config) EnsureComplete() error {
 	return nil
 }
 
-// This function is called to update the configuration in the file defined by the
+// PersistConfig updates the airshipctl config and kubeconfig files to match
-// ConfigFile name
+// the current Config and KubeConfig objects.
-// It will completely overwrite the existing file,
+// If either file did not previously exist, the file will be created.
-//    If the file specified by ConfigFile exists ts updates with the contents of the Config object
+// Otherwise, the file will be overwritten
-//    If the file specified by ConfigFile does not exist it will create a new file.
 func (c *Config) PersistConfig() error {
-	// Dont care if the file exists or not, will create if needed
+	airshipConfigYaml, err := c.ToYaml()
-	// We are 100% overwriting the existing file
-	configyaml, err := c.ToYaml()
 	if err != nil {
 		return err
 	}
 
-	// WriteFile doesn't create the directory , create it if needed
+	// WriteFile doesn't create the directory, create it if needed
 	configDir := filepath.Dir(c.loadedConfigPath)
 	err = os.MkdirAll(configDir, 0755)
 	if err != nil {
@@ -347,19 +353,13 @@ func (c *Config) PersistConfig() error {
 	}
 
 	// Write the Airship Config file
-	err = ioutil.WriteFile(c.loadedConfigPath, configyaml, 0644)
+	err = ioutil.WriteFile(c.loadedConfigPath, airshipConfigYaml, 0644)
 	if err != nil {
 		return err
 	}
 
-	// FIXME(howell): if this fails, then the results from the previous
-	// actions will persist, meaning that we might have overwritten our
-	// airshipconfig without updating our kubeconfig. A possible solution
-	// is to generate brand new config files and then write them at the
-	// end. That could still fail, but should be more robust
-
 	// Persist the kubeconfig file referenced
-	if err := clientcmd.ModifyConfig(c.loadedPathOptions, *c.kubeConfig, true); err != nil {
+	if err := clientcmd.WriteToFile(*c.kubeConfig, c.kubeConfigPath); err != nil {
 		return err
 	}
 
@@ -386,14 +386,15 @@ func (c *Config) SetLoadedConfigPath(lcp string) {
 	c.loadedConfigPath = lcp
 }
 
-func (c *Config) LoadedPathOptions() *clientcmd.PathOptions {
+func (c *Config) KubeConfigPath() string {
-	return c.loadedPathOptions
+	return c.kubeConfigPath
-}
-func (c *Config) SetLoadedPathOptions(po *clientcmd.PathOptions) {
-	c.loadedPathOptions = po
 }
 
-func (c *Config) KubeConfig() *kubeconfig.Config {
+func (c *Config) SetKubeConfigPath(kubeConfigPath string) {
+	c.kubeConfigPath = kubeConfigPath
+}
+
+func (c *Config) KubeConfig() *clientcmdapi.Config {
 	return c.kubeConfig
 }
 
@@ -441,7 +442,7 @@ func (c *Config) AddCluster(theCluster *ClusterOptions) (*Cluster, error) {
 	nCluster := NewCluster()
 	c.Clusters[theCluster.Name].ClusterTypes[theCluster.ClusterType] = nCluster
 	// Create a new Kubeconfig Cluster object as well
-	kcluster := kubeconfig.NewCluster()
+	kcluster := clientcmdapi.NewCluster()
 	clusterName := NewClusterComplexName()
 	clusterName.WithType(theCluster.Name, theCluster.ClusterType)
 	nCluster.NameInKubeconf = clusterName.Name()
@@ -541,7 +542,7 @@ func (c *Config) AddContext(theContext *ContextOptions) *Context {
 	nContext := NewContext()
 	c.Contexts[theContext.Name] = nContext
 	// Create a new Kubeconfig Context object as well
-	kContext := kubeconfig.NewContext()
+	kContext := clientcmdapi.NewContext()
 	nContext.NameInKubeconf = theContext.Name
 	contextName := NewClusterComplexName()
 	contextName.WithType(theContext.Name, theContext.ClusterType)
@@ -645,7 +646,7 @@ func (c *Config) AddAuthInfo(theAuthInfo *AuthInfoOptions) *AuthInfo {
 	nAuthInfo := NewAuthInfo()
 	c.AuthInfos[theAuthInfo.Name] = nAuthInfo
 	// Create a new Kubeconfig AuthInfo object as well
-	kAuthInfo := kubeconfig.NewAuthInfo()
+	kAuthInfo := clientcmdapi.NewAuthInfo()
 	nAuthInfo.SetKubeAuthInfo(kAuthInfo)
 	c.KubeConfig().AuthInfos[theAuthInfo.Name] = kAuthInfo
 
@@ -739,10 +740,10 @@ func (c *Cluster) PrettyString() string {
 		clusterName.ClusterName(), clusterName.ClusterType(), c)
 }
 
-func (c *Cluster) KubeCluster() *kubeconfig.Cluster {
+func (c *Cluster) KubeCluster() *clientcmdapi.Cluster {
 	return c.kCluster
 }
-func (c *Cluster) SetKubeCluster(kc *kubeconfig.Cluster) {
+func (c *Cluster) SetKubeCluster(kc *clientcmdapi.Cluster) {
 	c.kCluster = kc
 }
 
@@ -777,11 +778,11 @@ func (c *Context) PrettyString() string {
 		clusterName.ClusterName(), c.String())
 }
 
-func (c *Context) KubeContext() *kubeconfig.Context {
+func (c *Context) KubeContext() *clientcmdapi.Context {
 	return c.kContext
 }
 
-func (c *Context) SetKubeContext(kc *kubeconfig.Context) {
+func (c *Context) SetKubeContext(kc *clientcmdapi.Context) {
 	c.kContext = kc
 }
 
@@ -808,10 +809,10 @@ func (c *AuthInfo) String() string {
 	return string(kyaml)
 }
 
-func (c *AuthInfo) KubeAuthInfo() *kubeconfig.AuthInfo {
+func (c *AuthInfo) KubeAuthInfo() *clientcmdapi.AuthInfo {
 	return c.kAuthInfo
 }
-func (c *AuthInfo) SetKubeAuthInfo(kc *kubeconfig.AuthInfo) {
+func (c *AuthInfo) SetKubeAuthInfo(kc *clientcmdapi.AuthInfo) {
 	c.kAuthInfo = kc
 }
 
@@ -979,7 +980,7 @@ PLACEHOLDER UNTIL I IDENTIFY if CLIENTADM
 HAS SOMETHING LIKE THIS
 */
 
-func KClusterString(kCluster *kubeconfig.Cluster) string {
+func KClusterString(kCluster *clientcmdapi.Cluster) string {
 	yamlData, err := yaml.Marshal(&kCluster)
 	if err != nil {
 		return ""
@@ -987,7 +988,8 @@ func KClusterString(kCluster *kubeconfig.Cluster) string {
 
 	return string(yamlData)
 }
-func KContextString(kContext *kubeconfig.Context) string {
+
+func KContextString(kContext *clientcmdapi.Context) string {
 	yamlData, err := yaml.Marshal(&kContext)
 	if err != nil {
 		return ""
@@ -995,7 +997,8 @@ func KContextString(kContext *kubeconfig.Context) string {
 
 	return string(yamlData)
 }
-func KAuthInfoString(kAuthInfo *kubeconfig.AuthInfo) string {
+
+func KAuthInfoString(kAuthInfo *clientcmdapi.AuthInfo) string {
 	yamlData, err := yaml.Marshal(&kAuthInfo)
 	if err != nil {
 		return ""

pkg/config/config_test.go

@@ -26,7 +26,6 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
-	"k8s.io/client-go/tools/clientcmd"
 	kubeconfig "k8s.io/client-go/tools/clientcmd/api"
 
 	"opendev.org/airship/airshipctl/testutil"
@@ -224,10 +223,11 @@ func TestPersistConfig(t *testing.T) {
 	config := InitConfig(t)
 
 	err := config.PersistConfig()
-	assert.NoErrorf(t, err, "Unable to persist configuration expected at %v", config.LoadedConfigPath())
+	require.NoError(t, err)
 
-	kpo := config.LoadedPathOptions()
+	// Check that the files were created
-	assert.NotNil(t, kpo)
+	assert.FileExists(t, config.LoadedConfigPath())
+	assert.FileExists(t, config.KubeConfigPath())
 }
 
 func TestEnsureComplete(t *testing.T) {
@@ -347,11 +347,10 @@ func TestPurge(t *testing.T) {
 	require.NoError(t, err)
 
 	airConfigFile := filepath.Join(tempDir, AirshipConfig)
-	kConfigFile := filepath.Join(tempDir, AirshipKubeConfig)
 	config.SetLoadedConfigPath(airConfigFile)
-	kubePathOptions := clientcmd.NewDefaultPathOptions()
+
-	kubePathOptions.GlobalFile = kConfigFile
+	kConfigFile := filepath.Join(tempDir, AirshipKubeConfig)
-	config.SetLoadedPathOptions(kubePathOptions)
+	config.kubeConfigPath = kConfigFile
 
 	// Store it
 	err = config.PersistConfig()

pkg/config/constants.go

@@ -11,19 +11,22 @@ const (
 	AirshipClusterDefaultType = Target
 )
 
-//Sorted
+// Sorted
 var AllClusterTypes = [2]string{Ephemeral, Target}
 
 // Constants defining default values
 const (
-	AirshipConfigEnv        = "airshipconf"
-	AirshipConfig           = "config"
-	AirshipConfigDir        = ".airship"
-	AirshipConfigKind       = "Config"
-	AirshipConfigVersion    = "v1alpha1"
 	AirshipConfigGroup      = "airshipit.org"
+	AirshipConfigVersion    = "v1alpha1"
 	AirshipConfigApiVersion = AirshipConfigGroup + "/" + AirshipConfigVersion
-	AirshipKubeConfig       = "kubeconfig"
+	AirshipConfigKind       = "Config"
+
+	AirshipConfigDir  = ".airship"
+	AirshipConfig     = "config"
+	AirshipKubeConfig = "kubeconfig"
+
+	AirshipConfigEnv     = "AIRSHIPCONFIG"
+	AirshipKubeConfigEnv = "AIRSHIP_KUBECONFIG"
 )
 
 // Constants defining CLI flags
@@ -37,7 +40,7 @@ const (
 	FlagClusterType      = "cluster-type"
 	FlagContext          = "context"
 	FlagCurrentContext   = "current-context"
-	FlagConfigFilePath   = AirshipConfigEnv
+	FlagConfigFilePath   = "airshipconf"
 	FlagEmbedCerts       = "embed-certs"
 	FlagImpersonate      = "as"
 	FlagImpersonateGroup = "as-group"

pkg/config/test_utils.go

@@ -22,7 +22,6 @@ import (
 	"path/filepath"
 	"testing"
 
-	"k8s.io/client-go/tools/clientcmd"
 	kubeconfig "k8s.io/client-go/tools/clientcmd/api"
 
 	"github.com/stretchr/testify/require"
@@ -145,9 +144,7 @@ func InitConfig(t *testing.T) *Config {
 
 	conf := NewConfig()
 
-	kubePathOptions := clientcmd.NewDefaultPathOptions()
+	err = conf.LoadConfig(configPath, kubeConfigPath)
-	kubePathOptions.GlobalFile = kubeConfigPath
-	err = conf.LoadConfig(configPath, kubePathOptions)
 	require.NoError(t, err)
 
 	return conf

pkg/config/types.go

@@ -19,7 +19,6 @@ package config
 import (
 	"net/url"
 
-	"k8s.io/client-go/tools/clientcmd"
 	kubeconfig "k8s.io/client-go/tools/clientcmd/api"
 )
 
@@ -57,15 +56,15 @@ type Config struct {
 	// Such as Bootstrap, Workflows, Document, etc
 	ModulesConfig *Modules `json:"modules-config"`
 
-	// Private LoadedConfigPath is the full path to the the location of the config file
+	// loadedConfigPath is the full path to the the location of the config
-	// from which these config was loaded
+	// file from which this config was loaded
 	// +not persisted in file
 	loadedConfigPath string
 
-	// Private loadedPathOptions is the full path to the the location of the kubeconfig file
+	// kubeConfigPath is the full path to the the location of the
-	// associated with this airship config instance
+	// kubeconfig file associated with this airship config instance
 	// +not persisted in file
-	loadedPathOptions *clientcmd.PathOptions
+	kubeConfigPath string
 
 	// Private instance of Kube Config content as an object
 	kubeConfig *kubeconfig.Config

pkg/environment/settings.go

@@ -3,7 +3,6 @@ package environment
 import (
 	"os"
 	"path/filepath"
-	"strings"
 
 	"github.com/spf13/cobra"
 
@@ -64,67 +63,64 @@ func (a *AirshipCTLSettings) SetKubeConfigPath(kcp string) {
 func (a *AirshipCTLSettings) InitConfig() {
 	a.SetConfig(config.NewConfig())
 
-	a.setAirshipConfigPath()
+	a.initAirshipConfigPath()
+	a.initKubeConfigPath()
 
-	//Pass the airshipConfigPath and kubeConfig object
+	err := a.Config().LoadConfig(a.AirshipConfigPath(), a.KubeConfigPath())
-	err := a.Config().LoadConfig(a.AirshipConfigPath(), a.setKubePathOptions())
 	if err != nil {
 		// Should stop airshipctl
 		log.Fatal(err)
 	}
 }
 
-func (a *AirshipCTLSettings) setAirshipConfigPath() {
+func (a *AirshipCTLSettings) initAirshipConfigPath() {
-	// (1) If the airshipConfigPath was received as an argument its already set
+	// The airshipConfigPath may already have been received as a command line argument
-	if a.airshipConfigPath == "" {
+	if a.airshipConfigPath != "" {
-		// (2) If not , we can check if we got the Path via ENVIRONMENT variable,
+		return
-		// set the appropriate fields
-		a.setAirshipConfigPathFromEnv()
 	}
-	// (3) Check if the a.airshipConfigPath is empty still at this point , use the defaults
-	acp, home := a.replaceHomePlaceholder(a.airshipConfigPath)
-	a.airshipConfigPath = acp
-	if a.airshipConfigPath == "" {
-		a.airshipConfigPath = filepath.Join(home, config.AirshipConfigDir, config.AirshipConfig)
-	}
-}
 
-// setAirshipConfigPathFromEnv Get AIRSHIP CONFIG from an environment variable if set
+	// Otherwise, we can check if we got the path via ENVIRONMENT variable
-func (a *AirshipCTLSettings) setAirshipConfigPathFromEnv() {
-	// Check if AIRSHIPCONF env variable was set
-	// I have the path and name for the airship config file
 	a.airshipConfigPath = os.Getenv(config.AirshipConfigEnv)
-}
+	if a.airshipConfigPath != "" {
-
+		return
-func (a *AirshipCTLSettings) setKubePathOptions() *clientcmd.PathOptions {
-	// USe default expectations for Kubeconfig
-	kubePathOptions := clientcmd.NewDefaultPathOptions()
-	// No need to check the Environment , since we are relying on the kubeconfig defaults
-	// If we did not get an explicit kubeconfig definition on airshipctl
-	// as far as airshipctl is concerned will use the default expectations for the kubeconfig
-	// file location . This avoids messing up someones kubeconfig if they didnt explicitly want
-	// airshipctl to use it.
-	kcp, home := a.replaceHomePlaceholder(a.kubeConfigPath)
-	a.kubeConfigPath = kcp
-	if a.kubeConfigPath == "" {
-		a.kubeConfigPath = filepath.Join(home, config.AirshipConfigDir, config.AirshipKubeConfig)
 	}
-	//  We will always rely on tha airshipctl cli args or default for where to find kubeconfig
-	kubePathOptions.GlobalFile = a.kubeConfigPath
-	kubePathOptions.GlobalFileSubpath = a.kubeConfigPath
 
-	return kubePathOptions
+	// Otherwise, we'll try putting it in the home directory
+	homeDir := userHomeDir()
+	a.airshipConfigPath = filepath.Join(homeDir, config.AirshipConfigDir, config.AirshipConfig)
 }
 
-func (a *AirshipCTLSettings) replaceHomePlaceholder(configPath string) (string, string) {
+func (a *AirshipCTLSettings) initKubeConfigPath() {
-	home, err := os.UserHomeDir()
+	// NOTE(howell): This function will set the kubeConfigPath to the
+	// default location under the airship directory unless the user
+	// *explicitly* specifies a different location, either by setting the
+	// ENVIRONMENT variable or by passing a command line argument.
+	// This avoids messing up the user's kubeconfig if they didn't
+	// explicitly want airshipctl to use it.
+
+	// The kubeConfigPath may already have been received as a command line argument
+	if a.kubeConfigPath != "" {
+		return
+	}
+
+	// Otherwise, we can check if we got the path via ENVIRONMENT variable
+	a.kubeConfigPath = os.Getenv(config.AirshipKubeConfigEnv)
+	if a.kubeConfigPath != "" {
+		return
+	}
+
+	// Otherwise, we'll try putting it in the home directory
+	homeDir := userHomeDir()
+	a.kubeConfigPath = filepath.Join(homeDir, config.AirshipConfigDir, config.AirshipKubeConfig)
+}
+
+// userHomeDir is a utility function that wraps os.UserHomeDir and returns no
+// errors. If the user has no home directory, the returned value will be the
+// empty string
+func userHomeDir() string {
+	homeDir, err := os.UserHomeDir()
 	if err != nil {
-		// Use defaults under current directory
+		homeDir = ""
-		home = ""
 	}
-	if configPath == "" {
+	return homeDir
-		return configPath, home
-	}
-
-	return strings.Replace(configPath, HomePlaceholder, home, 1), home
 }

pkg/environment/settings_test.go

@@ -17,6 +17,7 @@ limitations under the License.
 package environment
 
 import (
+	"io/ioutil"
 	"os"
 	"path/filepath"
 	"testing"
@@ -36,25 +37,107 @@ func TestInitFlags(t *testing.T) {
 	assert.True(t, testCmd.HasPersistentFlags())
 }
 
-func TestSpecifyAirConfigFromEnv(t *testing.T) {
+func TestInitConfig(t *testing.T) {
-	fakeConfig := "FakeConfigPath"
+	t.Run("DefaultToHomeDirectory", func(subTest *testing.T) {
-	err := os.Setenv(config.AirshipConfigEnv, fakeConfig)
+		// Set up a fake $HOME directory
+		testDir := makeTestDir(t)
+		defer deleteTestDir(t, testDir)
+		defer setHome(testDir)()
+
+		var testSettings AirshipCTLSettings
+		expectedAirshipConfig := filepath.Join(testDir, config.AirshipConfigDir, config.AirshipConfig)
+		expectedKubeConfig := filepath.Join(testDir, config.AirshipConfigDir, config.AirshipKubeConfig)
+
+		testSettings.InitConfig()
+		assert.Equal(t, expectedAirshipConfig, testSettings.AirshipConfigPath())
+		assert.Equal(t, expectedKubeConfig, testSettings.KubeConfigPath())
+	})
+
+	t.Run("PreferEnvToDefault", func(subTest *testing.T) {
+		// Set up a fake $HOME directory
+		testDir := makeTestDir(t)
+		defer deleteTestDir(t, testDir)
+		defer setHome(testDir)()
+
+		var testSettings AirshipCTLSettings
+		expectedAirshipConfig := filepath.Join(testDir, "airshipEnv")
+		expectedKubeConfig := filepath.Join(testDir, "kubeEnv")
+
+		os.Setenv(config.AirshipConfigEnv, expectedAirshipConfig)
+		os.Setenv(config.AirshipKubeConfigEnv, expectedKubeConfig)
+		defer os.Unsetenv(config.AirshipConfigEnv)
+		defer os.Unsetenv(config.AirshipKubeConfigEnv)
+
+		testSettings.InitConfig()
+		assert.Equal(t, expectedAirshipConfig, testSettings.AirshipConfigPath())
+		assert.Equal(t, expectedKubeConfig, testSettings.KubeConfigPath())
+	})
+
+	t.Run("PreferCmdLineArgToDefault", func(subTest *testing.T) {
+		// Set up a fake $HOME directory
+		testDir := makeTestDir(t)
+		defer deleteTestDir(t, testDir)
+		defer setHome(testDir)()
+
+		var testSettings AirshipCTLSettings
+		expectedAirshipConfig := filepath.Join(testDir, "airshipCmdLine")
+		expectedKubeConfig := filepath.Join(testDir, "kubeCmdLine")
+
+		testSettings.SetAirshipConfigPath(expectedAirshipConfig)
+		testSettings.SetKubeConfigPath(expectedKubeConfig)
+
+		// InitConfig should not change any values
+		testSettings.InitConfig()
+		assert.Equal(t, expectedAirshipConfig, testSettings.AirshipConfigPath())
+		assert.Equal(t, expectedKubeConfig, testSettings.KubeConfigPath())
+	})
+
+	t.Run("PreferCmdLineArgToEnv", func(subTest *testing.T) {
+		// Set up a fake $HOME directory
+		testDir := makeTestDir(t)
+		defer deleteTestDir(t, testDir)
+		defer setHome(testDir)()
+
+		var testSettings AirshipCTLSettings
+		expectedAirshipConfig := filepath.Join(testDir, "airshipCmdLine")
+		expectedKubeConfig := filepath.Join(testDir, "kubeCmdLine")
+
+		// set up "decoy" environment variables. These should be
+		// ignored, since we're simulating passing in command line
+		// arguments
+		wrongAirshipConfig := filepath.Join(testDir, "wrongAirshipConfig")
+		wrongKubeConfig := filepath.Join(testDir, "wrongKubeConfig")
+		os.Setenv(config.AirshipConfigEnv, wrongAirshipConfig)
+		os.Setenv(config.AirshipKubeConfigEnv, wrongKubeConfig)
+		defer os.Unsetenv(config.AirshipConfigEnv)
+		defer os.Unsetenv(config.AirshipKubeConfigEnv)
+
+		testSettings.SetAirshipConfigPath(expectedAirshipConfig)
+		testSettings.SetKubeConfigPath(expectedKubeConfig)
+
+		testSettings.InitConfig()
+		assert.Equal(t, expectedAirshipConfig, testSettings.AirshipConfigPath())
+		assert.Equal(t, expectedKubeConfig, testSettings.KubeConfigPath())
+	})
+}
+
+func makeTestDir(t *testing.T) string {
+	testDir, err := ioutil.TempDir("", "airship-test")
 	require.NoError(t, err)
-
+	return testDir
-	settings := &AirshipCTLSettings{}
-	settings.InitConfig()
-
-	assert.EqualValues(t, fakeConfig, settings.AirshipConfigPath())
 }
 
-func TestGetSetPaths(t *testing.T) {
+func deleteTestDir(t *testing.T, path string) {
-	settings := &AirshipCTLSettings{}
+	err := os.Remove(path)
-	settings.InitConfig()
+	require.NoError(t, err)
-	airConfigFile := filepath.Join(config.AirshipConfigDir, config.AirshipConfig)
+}
-	kConfigFile := filepath.Join(config.AirshipConfigDir, config.AirshipKubeConfig)
+
-	settings.SetAirshipConfigPath(airConfigFile)
+// setHome sets the HOME environment variable to `path`, and returns a function
-	assert.EqualValues(t, airConfigFile, settings.AirshipConfigPath())
+// that can be used to reset HOME to its original value
-
+func setHome(path string) (resetHome func()) {
-	settings.SetKubeConfigPath(kConfigFile)
+	oldHome := os.Getenv("HOME")
-	assert.EqualValues(t, kConfigFile, settings.KubeConfigPath())
+	os.Setenv("HOME", path)
+	return func() {
+		os.Setenv("HOME", oldHome)
+	}
 }