tests/e2e: Generalize GetEnv (openservicemesh#1844)

Addressing:
openservicemesh#1828 (comment)

ci/cmd/maestro.go

@@ -15,6 +15,7 @@ import (
 	"github.com/openservicemesh/osm/demo/cmd/common"
 	"github.com/openservicemesh/osm/pkg/constants"
 	"github.com/openservicemesh/osm/pkg/logger"
+	"github.com/openservicemesh/osm/pkg/utils"
 )
 
 var log = logger.NewPretty("ci/maestro")
@@ -36,14 +37,14 @@ var (
 	bookstoreV2Selector      = fmt.Sprintf("%s=%s", selectorKey, bookstoreV2Label)
 	bookWarehouseSelector    = fmt.Sprintf("%s=%s", selectorKey, bookWarehouseLabel)
 
-	osmNamespace    = common.GetEnv(maestro.OSMNamespaceEnvVar, "osm-system")
-	bookbuyerNS     = common.GetEnv(maestro.BookbuyerNamespaceEnvVar, "bookbuyer")
-	bookthiefNS     = common.GetEnv(maestro.BookthiefNamespaceEnvVar, "bookthief")
-	bookstoreNS     = common.GetEnv(maestro.BookstoreNamespaceEnvVar, "bookstore")
-	bookWarehouseNS = common.GetEnv(common.BookwarehouseNamespaceEnvVar, "bookwarehouse")
+	osmNamespace    = utils.GetEnv(maestro.OSMNamespaceEnvVar, "osm-system")
+	bookbuyerNS     = utils.GetEnv(maestro.BookbuyerNamespaceEnvVar, "bookbuyer")
+	bookthiefNS     = utils.GetEnv(maestro.BookthiefNamespaceEnvVar, "bookthief")
+	bookstoreNS     = utils.GetEnv(maestro.BookstoreNamespaceEnvVar, "bookstore")
+	bookWarehouseNS = utils.GetEnv(common.BookwarehouseNamespaceEnvVar, "bookwarehouse")
 
-	maxPodWaitString = common.GetEnv(maestro.WaitForPodTimeSecondsEnvVar, "30")
-	maxOKWaitString  = common.GetEnv(maestro.WaitForOKSecondsEnvVar, "30")
+	maxPodWaitString = utils.GetEnv(maestro.WaitForPodTimeSecondsEnvVar, "30")
+	maxOKWaitString  = utils.GetEnv(maestro.WaitForOKSecondsEnvVar, "30")
 	meshName         = osmNamespace
 
 	// Mesh namespaces

demo/cmd/bookbuyer/bookbuyer.go

@@ -15,6 +15,7 @@ import (
 
 	"github.com/openservicemesh/osm/demo/cmd/common"
 	"github.com/openservicemesh/osm/pkg/logger"
+	"github.com/openservicemesh/osm/pkg/utils"
 )
 
 const (
@@ -30,7 +31,7 @@ var (
 	log               = logger.NewPretty(participantName)
 	port              = flag.Int("port", 80, "port on which this app is listening for incoming HTTP")
 	path              = flag.String("path", ".", "path to the HTML template")
-	numConnectionsStr = common.GetEnv("CI_CLIENT_CONCURRENT_CONNECTIONS", "1")
+	numConnectionsStr = utils.GetEnv("CI_CLIENT_CONCURRENT_CONNECTIONS", "1")
 )
 
 type handler struct {
@@ -40,7 +41,7 @@ type handler struct {
 }
 
 func getIdentity() string {
-	return common.GetEnv("IDENTITY", "Bookbuyer")
+	return utils.GetEnv("IDENTITY", "Bookbuyer")
 }
 
 func renderTemplate(w http.ResponseWriter) {

demo/cmd/bookthief/bookthief.go

@@ -12,6 +12,7 @@ import (
 
 	"github.com/openservicemesh/osm/demo/cmd/common"
 	"github.com/openservicemesh/osm/pkg/logger"
+	"github.com/openservicemesh/osm/pkg/utils"
 )
 
 const (
@@ -46,7 +47,7 @@ func renderTemplate(w http.ResponseWriter) {
 	}
 }
 func getIdentity() string {
-	return common.GetEnv("IDENTITY", "Bookthief")
+	return utils.GetEnv("IDENTITY", "Bookthief")
 }
 
 type handler struct {

demo/cmd/common/books.go

@@ -11,6 +11,7 @@ import (
 	"time"
 
 	"github.com/openservicemesh/osm/pkg/logger"
+	"github.com/openservicemesh/osm/pkg/utils"
 )
 
 const (
@@ -29,10 +30,10 @@ var (
 	// enableEgress determines whether egress is enabled
 	enableEgress = os.Getenv(EnableEgressEnvVar) == "true"
 
-	sleepDurationBetweenRequestsSecondsStr = GetEnv("CI_SLEEP_BETWEEN_REQUESTS_SECONDS", "1")
-	minSuccessThresholdStr                 = GetEnv("CI_MIN_SUCCESS_THRESHOLD", "1")
-	maxIterationsStr                       = GetEnv("CI_MAX_ITERATIONS_THRESHOLD", "0") // 0 for unlimited
-	bookstoreServiceName                   = GetEnv("BOOKSTORE_SVC", "bookstore")
+	sleepDurationBetweenRequestsSecondsStr = utils.GetEnv("CI_SLEEP_BETWEEN_REQUESTS_SECONDS", "1")
+	minSuccessThresholdStr                 = utils.GetEnv("CI_MIN_SUCCESS_THRESHOLD", "1")
+	maxIterationsStr                       = utils.GetEnv("CI_MAX_ITERATIONS_THRESHOLD", "0") // 0 for unlimited
+	bookstoreServiceName                   = utils.GetEnv("BOOKSTORE_SVC", "bookstore")
 	bookstoreNamespace                     = os.Getenv(BookstoreNamespaceEnvVar)
 	warehouseServiceName                   = "bookwarehouse"
 	bookwarehouseNamespace                 = os.Getenv(BookwarehouseNamespaceEnvVar)
@@ -93,15 +94,6 @@ func RestockBooks(amount int) {
 	log.Info().Msgf("RestockBooks (%s) finished w/ status: %s %d ", chargeAccountURL, resp.Status, resp.StatusCode)
 }
 
-// GetEnv is much  like os.Getenv() but with a default value.
-func GetEnv(envVar string, defaultValue string) string {
-	val := os.Getenv(envVar)
-	if val == "" {
-		return defaultValue
-	}
-	return val
-}
-
 // GetBooks reaches out to the bookstore and buys/steals books. This is invoked by the bookbuyer and the bookthief.
 func GetBooks(participantName string, meshExpectedResponseCode int, booksCount *int64, booksCountV1 *int64, booksCountV2 *int64) {
 	minSuccessThreshold, maxIterations, sleepDurationBetweenRequests := getEnvVars(participantName)
@@ -285,7 +277,7 @@ func getEnvVars(participantName string) (minSuccessThreshold int64, maxIteration
 
 // GetExpectedResponseCodeFromEnvVar returns the expected response code based on the given environment variable
 func GetExpectedResponseCodeFromEnvVar(envVar, defaultValue string) int {
-	expectedRespCodeStr := GetEnv(envVar, defaultValue)
+	expectedRespCodeStr := utils.GetEnv(envVar, defaultValue)
 	expectedRespCode, err := strconv.ParseInt(expectedRespCodeStr, 10, 0)
 	if err != nil {
 		log.Fatal().Err(err).Msgf("Could not convert environment variable %s='%s' to int", envVar, expectedRespCodeStr)

pkg/utils/env.go

@@ -0,0 +1,13 @@
+package utils
+
+import "os"
+
+// GetEnv is a convenience wrapper for os.Getenv() with additional default value return
+// when empty or unset
+func GetEnv(envVar string, defaultValue string) string {
+	val := os.Getenv(envVar)
+	if val == "" {
+		return defaultValue
+	}
+	return val
+}

pkg/utils/env_test.go

@@ -0,0 +1,32 @@
+package utils
+
+import (
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestGetEnv(t *testing.T) {
+	const (
+		EnvVarName         = "TEST_VAR"
+		EnvVarValue        = "test_value"
+		EnvVarDefaultValue = "default_value"
+	)
+
+	assert := assert.New(t)
+
+	// make sure the variable is unset before starting the test
+	assert.NoError(os.Unsetenv(EnvVarName))
+
+	// Expect Default when not set
+	assert.Equal(EnvVarDefaultValue, GetEnv(EnvVarName, EnvVarDefaultValue))
+
+	// Set it, expect actual value when set
+	assert.NoError(os.Setenv(EnvVarName, EnvVarValue))
+	assert.Equal(EnvVarValue, GetEnv(EnvVarName, EnvVarDefaultValue))
+
+	// Unset it, expect default again
+	assert.NoError(os.Unsetenv(EnvVarName))
+	assert.Equal(EnvVarDefaultValue, GetEnv(EnvVarName, EnvVarDefaultValue))
+}

tests/e2e/common.go

@@ -14,6 +14,7 @@ import (
 	"time"
 
 	. "github.com/onsi/ginkgo"
+	"github.com/openservicemesh/osm/pkg/utils"
 
 	"github.com/docker/docker/client"
 	"github.com/pkg/errors"
@@ -36,6 +37,8 @@ const (
 	registrySecretName = "acr-creds"
 	// constant, default name for the mesh
 	defaultMeshName = "osm-system"
+	// default image tag
+	defaultImageTag = "latest"
 )
 
 // OsmTestData stores common state, variables and flags for the test at hand
@@ -85,21 +88,8 @@ func registerFlags(td *OsmTestData) {
 	flag.StringVar(&td.ctrRegistryUser, "ctrRegistryUser", os.Getenv("CTR_REGISTRY_USER"), "Container registry")
 	flag.StringVar(&td.ctrRegistryPassword, "ctrRegistrySecret", os.Getenv("CTR_REGISTRY_PASSWORD"), "Container registry secret")
 
-	flag.StringVar(&td.osmImageTag, "osmImageTag", func() string {
-		tmp := os.Getenv("CTR_TAG")
-		if len(tmp) != 0 {
-			return tmp
-		}
-		return "latest"
-	}(), "OSM image tag")
-
-	flag.StringVar(&td.osmNamespace, "meshName", func() string {
-		tmp := os.Getenv("K8S_NAMESPACE")
-		if len(tmp) != 0 {
-			return tmp
-		}
-		return defaultMeshName
-	}(), "OSM mesh name")
+	flag.StringVar(&td.osmImageTag, "osmImageTag", utils.GetEnv("CTR_TAG", defaultImageTag), "OSM image tag")
+	flag.StringVar(&td.osmNamespace, "osmNamespace", utils.GetEnv("K8S_NAMESPACE", defaultMeshName), "OSM mesh name")
 }
 
 // AreRegistryCredsPresent checks if Registry Credentials are present