Add option to allow enviornment variables using file (#1433)

* Add `GetEnvsFromFile` to `util`
* Add to `podspec` flags `--env-file` and `EnvFile` to `PodSpec`.
* If `env-file` is specified load env vars from file to memory,
  convert them into ordered map and pass them to UpdateEnvVars function
  by setting custom args for each one of them instead of using command line args.

Signed-off-by: Boaz <boaz.shuster.github@gmail.com>

CHANGELOG.adoc

@@ -16,6 +16,10 @@
 |===
 | | Description | PR
 
+| 🎁
+| Add `--env-file` option to function create/update command
+| https://github.com/knative/client/pull/1423[#1419]
+
 | ✨
 | Remove `DeprecatedImageDigest` field
 | https://github.com/knative/client/pull/1454[#1454]

docs/cmd/kn_container_add.md

@@ -31,6 +31,7 @@ kn container add NAME
       --arg stringArray              Add argument to the container command. Example: --arg myArg1 --arg --myArg2 --arg myArg3=3. You can use this flag multiple times.
       --cmd stringArray              Specify command to be used as entrypoint instead of default one. Example: --cmd /app/start or --cmd sh --cmd /app/start.sh or --cmd /app/start --arg myArg to pass additional arguments.
   -e, --env stringArray              Environment variable to set. NAME=value; you may provide this flag any number of times to set multiple environment variables. To unset, specify the environment variable name followed by a "-" (e.g., NAME-).
+      --env-file string              Path to a file containing environment variables (e.g. --env-file=/home/knative/service1/env).
       --env-from stringArray         Add environment variables from a ConfigMap (prefix cm: or config-map:) or a Secret (prefix secret:). Example: --env-from cm:myconfigmap or --env-from secret:mysecret. You can use this flag multiple times. To unset a ConfigMap/Secret reference, append "-" to the name, e.g. --env-from cm:myconfigmap-.
       --env-value-from stringArray   Add environment variable from a value of key in ConfigMap (prefix cm: or config-map:) or a Secret (prefix sc: or secret:). Example: --env-value-from NAME=cm:myconfigmap:key or --env-value-from NAME=secret:mysecret:key. You can use this flag multiple times. To unset a value from a ConfigMap/Secret key reference, append "-" to the key, e.g. --env-value-from ENV-.
       --extra-containers string      Specify path to file including definition for additional containers, alternatively use '-' to read from stdin. Example: --extra-containers ./containers.yaml or --extra-containers -.

docs/cmd/kn_service_apply.md

@@ -40,6 +40,7 @@ kn service apply s0 --filename my-svc.yml
       --concurrency-target int            Recommendation for when to scale up based on the concurrent number of incoming request. Defaults to --concurrency-limit when given.
       --concurrency-utilization int       Percentage of concurrent requests utilization before scaling up. (default 70)
   -e, --env stringArray                   Environment variable to set. NAME=value; you may provide this flag any number of times to set multiple environment variables. To unset, specify the environment variable name followed by a "-" (e.g., NAME-).
+      --env-file string                   Path to a file containing environment variables (e.g. --env-file=/home/knative/service1/env).
       --env-from stringArray              Add environment variables from a ConfigMap (prefix cm: or config-map:) or a Secret (prefix secret:). Example: --env-from cm:myconfigmap or --env-from secret:mysecret. You can use this flag multiple times. To unset a ConfigMap/Secret reference, append "-" to the name, e.g. --env-from cm:myconfigmap-.
       --env-value-from stringArray        Add environment variable from a value of key in ConfigMap (prefix cm: or config-map:) or a Secret (prefix sc: or secret:). Example: --env-value-from NAME=cm:myconfigmap:key or --env-value-from NAME=secret:mysecret:key. You can use this flag multiple times. To unset a value from a ConfigMap/Secret key reference, append "-" to the key, e.g. --env-value-from ENV-.
       --extra-containers string           Specify path to file including definition for additional containers, alternatively use '-' to read from stdin. Example: --extra-containers ./containers.yaml or --extra-containers -.

docs/cmd/kn_service_create.md

@@ -65,6 +65,7 @@ kn service create NAME --image IMAGE
       --concurrency-target int            Recommendation for when to scale up based on the concurrent number of incoming request. Defaults to --concurrency-limit when given.
       --concurrency-utilization int       Percentage of concurrent requests utilization before scaling up. (default 70)
   -e, --env stringArray                   Environment variable to set. NAME=value; you may provide this flag any number of times to set multiple environment variables. To unset, specify the environment variable name followed by a "-" (e.g., NAME-).
+      --env-file string                   Path to a file containing environment variables (e.g. --env-file=/home/knative/service1/env).
       --env-from stringArray              Add environment variables from a ConfigMap (prefix cm: or config-map:) or a Secret (prefix secret:). Example: --env-from cm:myconfigmap or --env-from secret:mysecret. You can use this flag multiple times. To unset a ConfigMap/Secret reference, append "-" to the name, e.g. --env-from cm:myconfigmap-.
       --env-value-from stringArray        Add environment variable from a value of key in ConfigMap (prefix cm: or config-map:) or a Secret (prefix sc: or secret:). Example: --env-value-from NAME=cm:myconfigmap:key or --env-value-from NAME=secret:mysecret:key. You can use this flag multiple times. To unset a value from a ConfigMap/Secret key reference, append "-" to the key, e.g. --env-value-from ENV-.
       --extra-containers string           Specify path to file including definition for additional containers, alternatively use '-' to read from stdin. Example: --extra-containers ./containers.yaml or --extra-containers -.

docs/cmd/kn_service_update.md

@@ -50,6 +50,7 @@ kn service update NAME
       --concurrency-target int            Recommendation for when to scale up based on the concurrent number of incoming request. Defaults to --concurrency-limit when given.
       --concurrency-utilization int       Percentage of concurrent requests utilization before scaling up. (default 70)
   -e, --env stringArray                   Environment variable to set. NAME=value; you may provide this flag any number of times to set multiple environment variables. To unset, specify the environment variable name followed by a "-" (e.g., NAME-).
+      --env-file string                   Path to a file containing environment variables (e.g. --env-file=/home/knative/service1/env).
       --env-from stringArray              Add environment variables from a ConfigMap (prefix cm: or config-map:) or a Secret (prefix secret:). Example: --env-from cm:myconfigmap or --env-from secret:mysecret. You can use this flag multiple times. To unset a ConfigMap/Secret reference, append "-" to the name, e.g. --env-from cm:myconfigmap-.
       --env-value-from stringArray        Add environment variable from a value of key in ConfigMap (prefix cm: or config-map:) or a Secret (prefix sc: or secret:). Example: --env-value-from NAME=cm:myconfigmap:key or --env-value-from NAME=secret:mysecret:key. You can use this flag multiple times. To unset a value from a ConfigMap/Secret key reference, append "-" to the key, e.g. --env-value-from ENV-.
       --extra-containers string           Specify path to file including definition for additional containers, alternatively use '-' to read from stdin. Example: --extra-containers ./containers.yaml or --extra-containers -.

docs/cmd/kn_source_container_create.md

@@ -20,6 +20,7 @@ kn source container create NAME --image IMAGE --sink SINK
       --arg stringArray              Add argument to the container command. Example: --arg myArg1 --arg --myArg2 --arg myArg3=3. You can use this flag multiple times.
       --cmd stringArray              Specify command to be used as entrypoint instead of default one. Example: --cmd /app/start or --cmd sh --cmd /app/start.sh or --cmd /app/start --arg myArg to pass additional arguments.
   -e, --env stringArray              Environment variable to set. NAME=value; you may provide this flag any number of times to set multiple environment variables. To unset, specify the environment variable name followed by a "-" (e.g., NAME-).
+      --env-file string              Path to a file containing environment variables (e.g. --env-file=/home/knative/service1/env).
       --env-from stringArray         Add environment variables from a ConfigMap (prefix cm: or config-map:) or a Secret (prefix secret:). Example: --env-from cm:myconfigmap or --env-from secret:mysecret. You can use this flag multiple times. To unset a ConfigMap/Secret reference, append "-" to the name, e.g. --env-from cm:myconfigmap-.
       --env-value-from stringArray   Add environment variable from a value of key in ConfigMap (prefix cm: or config-map:) or a Secret (prefix sc: or secret:). Example: --env-value-from NAME=cm:myconfigmap:key or --env-value-from NAME=secret:mysecret:key. You can use this flag multiple times. To unset a value from a ConfigMap/Secret key reference, append "-" to the key, e.g. --env-value-from ENV-.
       --extra-containers string      Specify path to file including definition for additional containers, alternatively use '-' to read from stdin. Example: --extra-containers ./containers.yaml or --extra-containers -.

docs/cmd/kn_source_container_update.md

@@ -20,6 +20,7 @@ kn source container update NAME --image IMAGE
       --arg stringArray              Add argument to the container command. Example: --arg myArg1 --arg --myArg2 --arg myArg3=3. You can use this flag multiple times.
       --cmd stringArray              Specify command to be used as entrypoint instead of default one. Example: --cmd /app/start or --cmd sh --cmd /app/start.sh or --cmd /app/start --arg myArg to pass additional arguments.
   -e, --env stringArray              Environment variable to set. NAME=value; you may provide this flag any number of times to set multiple environment variables. To unset, specify the environment variable name followed by a "-" (e.g., NAME-).
+      --env-file string              Path to a file containing environment variables (e.g. --env-file=/home/knative/service1/env).
       --env-from stringArray         Add environment variables from a ConfigMap (prefix cm: or config-map:) or a Secret (prefix secret:). Example: --env-from cm:myconfigmap or --env-from secret:mysecret. You can use this flag multiple times. To unset a ConfigMap/Secret reference, append "-" to the name, e.g. --env-from cm:myconfigmap-.
       --env-value-from stringArray   Add environment variable from a value of key in ConfigMap (prefix cm: or config-map:) or a Secret (prefix sc: or secret:). Example: --env-value-from NAME=cm:myconfigmap:key or --env-value-from NAME=secret:mysecret:key. You can use this flag multiple times. To unset a value from a ConfigMap/Secret key reference, append "-" to the key, e.g. --env-value-from ENV-.
       --extra-containers string      Specify path to file including definition for additional containers, alternatively use '-' to read from stdin. Example: --extra-containers ./containers.yaml or --extra-containers -.

pkg/kn/flags/podspec.go

@@ -32,6 +32,7 @@ type PodSpecFlags struct {
 	Env          []string
 	EnvFrom      []string
 	EnvValueFrom []string
+	EnvFile      string
 	Mount        []string
 	Volume       []string
 
@@ -85,6 +86,9 @@ func (p *PodSpecFlags) AddFlags(flagset *pflag.FlagSet) []string {
 			"To unset, specify the environment variable name followed by a \"-\" (e.g., NAME-).")
 	flagNames = append(flagNames, "env")
 
+	flagset.StringVarP(&p.EnvFile, "env-file", "", "", "Path to a file containing environment variables (e.g. --env-file=/home/knative/service1/env).")
+	flagNames = append(flagNames, "env-file")
+
 	flagset.StringArrayVarP(&p.EnvValueFrom, "env-value-from", "", []string{},
 		"Add environment variable from a value of key in ConfigMap (prefix cm: or config-map:) or a Secret (prefix sc: or secret:). "+
 			"Example: --env-value-from NAME=cm:myconfigmap:key or --env-value-from NAME=secret:mysecret:key. "+
@@ -169,7 +173,7 @@ func (p *PodSpecFlags) AddFlags(flagset *pflag.FlagSet) []string {
 func (p *PodSpecFlags) ResolvePodSpec(podSpec *corev1.PodSpec, flags *pflag.FlagSet, allArgs []string) error {
 	var err error
 
-	if flags.Changed("env") || flags.Changed("env-value-from") {
+	if flags.Changed("env") || flags.Changed("env-value-from") || flags.Changed("env-file") {
 		envToUpdate, envToRemove, err := util.OrderedMapAndRemovalListFromArray(p.Env, "=")
 		if err != nil {
 			return fmt.Errorf("Invalid --env: %w", err)
@@ -180,7 +184,24 @@ func (p *PodSpecFlags) ResolvePodSpec(podSpec *corev1.PodSpec, flags *pflag.Flag
 			return fmt.Errorf("Invalid --env-value-from: %w", err)
 		}
 
-		err = UpdateEnvVars(podSpec, allArgs, envToUpdate, envToRemove, envValueFromToUpdate, envValueFromToRemove)
+		envsFileToUpdate := util.NewOrderedMap()
+		envsFileToRemove := []string{}
+		if p.EnvFile != "" {
+			envsFromFile, err := util.GetEnvsFromFile(p.EnvFile, "=")
+			if err != nil {
+				return fmt.Errorf("Invalid --env-file: %w", err)
+			}
+			envsFileToUpdate, envsFileToRemove, err = util.OrderedMapAndRemovalListFromArray(envsFromFile, "=")
+			if err != nil {
+				return fmt.Errorf("Invalid --env: %w", err)
+			}
+		}
+
+		err = UpdateEnvVars(
+			podSpec, allArgs, envToUpdate, envToRemove,
+			envValueFromToUpdate, envValueFromToRemove,
+			p.EnvFile, envsFileToUpdate, envsFileToRemove,
+		)
 		if err != nil {
 			return err
 		}

pkg/kn/flags/podspec_helper.go

@@ -56,17 +56,22 @@ func containerOfPodSpec(spec *corev1.PodSpec) *corev1.Container {
 // UpdateEnvVars gives the configuration all the env var values listed in the given map of
 // vars.  Does not touch any environment variables not mentioned, but it can add
 // new env vars and change the values of existing ones.
-func UpdateEnvVars(spec *corev1.PodSpec,
-	allArgs []string, envToUpdate *util.OrderedMap, envToRemove []string, envValueFromToUpdate *util.OrderedMap, envValueFromToRemove []string) error {
+func UpdateEnvVars(spec *corev1.PodSpec, allArgs []string,
+	envToUpdate *util.OrderedMap, envToRemove []string,
+	envValueFromToUpdate *util.OrderedMap, envValueFromToRemove []string,
+	envFileName string, envValueFileToUpdate *util.OrderedMap, envValueFileToRemove []string,
+) error {
 	container := containerOfPodSpec(spec)
 
 	allEnvsToUpdate := util.NewOrderedMap()
 
 	envIterator := envToUpdate.Iterator()
 	envValueFromIterator := envValueFromToUpdate.Iterator()
+	envValueFileIterator := envValueFileToUpdate.Iterator()
 
 	envKey, envValue, envExists := envIterator.NextString()
 	envValueFromKey, envValueFromValue, envValueFromExists := envValueFromIterator.NextString()
+	envValueFileKey, envValueFileValue, envValueFileExists := envValueFileIterator.NextString()
 	for _, arg := range allArgs {
 		// envs are stored as NAME=value
 		if envExists && isValidEnvArg(arg, envKey, envValue) {
@@ -86,6 +91,14 @@ func UpdateEnvVars(spec *corev1.PodSpec,
 				ValueFrom: envVarSource,
 			})
 			envValueFromKey, envValueFromValue, envValueFromExists = envValueFromIterator.NextString()
+		} else if envValueFileExists && isValidEnvValueFileArg(arg, envFileName) {
+			for envValueFileExists {
+				allEnvsToUpdate.Set(envValueFileKey, corev1.EnvVar{
+					Name:  envValueFileKey,
+					Value: envValueFileValue,
+				})
+				envValueFileKey, envValueFileValue, envValueFileExists = envValueFileIterator.NextString()
+			}
 		}
 	}
 
@@ -109,6 +122,12 @@ func isValidEnvValueFromArg(arg, envValueFromKey, envValueFromValue string) bool
 	return strings.HasPrefix(arg, envValueFromKey+"="+envValueFromValue) || strings.HasPrefix(arg, "--env-value-from="+envValueFromKey+"="+envValueFromValue)
 }
 
+// isValidEnvValueFileArg checks that the input arg is a valid argument for specifying env from value,
+// ie. stored as NAME=secret:sercretName:key or NAME=config-map:cmName:key
+func isValidEnvValueFileArg(arg, envFileName string) bool {
+	return strings.HasPrefix(arg, envFileName) || strings.HasPrefix(arg, "--env-file="+envFileName)
+}
+
 // UpdateEnvFrom updates envFrom
 func UpdateEnvFrom(spec *corev1.PodSpec, toUpdate []string, toRemove []string) error {
 	container := containerOfPodSpec(spec)

pkg/kn/flags/podspec_helper_test.go

@@ -51,7 +51,7 @@ func TestUpdateEnvVarsNew(t *testing.T) {
 	envToUpdate, envToRemove, err := util.OrderedMapAndRemovalListFromArray(argsEnv, "=")
 	assert.NilError(t, err)
 	args := append([]string{"command"}, argsEnv...)
-	err = UpdateEnvVars(spec, args, envToUpdate, envToRemove, util.NewOrderedMap(), []string{})
+	err = UpdateEnvVars(spec, args, envToUpdate, envToRemove, util.NewOrderedMap(), []string{}, "", util.NewOrderedMap(), []string{})
 	assert.NilError(t, err)
 	assert.DeepEqual(t, expected, spec.Containers[0].Env)
 }
@@ -71,7 +71,7 @@ func TestUpdateEnvVarsMixedEnvOrder(t *testing.T) {
 	envToUpdate, envToRemove, err := util.OrderedMapAndRemovalListFromArray(argsEnv, "=")
 	assert.NilError(t, err)
 	args := append([]string{"command"}, argsEnv...)
-	err = UpdateEnvVars(spec, args, envToUpdate, envToRemove, util.NewOrderedMap(), []string{})
+	err = UpdateEnvVars(spec, args, envToUpdate, envToRemove, util.NewOrderedMap(), []string{}, "", util.NewOrderedMap(), []string{})
 	assert.NilError(t, err)
 	assert.DeepEqual(t, expected, spec.Containers[0].Env)
 }
@@ -121,7 +121,7 @@ func TestUpdateEnvVarsValueFromNew(t *testing.T) {
 	args := append([]string{"command"}, argsEnvValueFrom...)
 	envValueFromToUpdate, envValueFromToRemove, err := util.OrderedMapAndRemovalListFromArray(argsEnvValueFrom, "=")
 	assert.NilError(t, err)
-	err = UpdateEnvVars(spec, args, util.NewOrderedMap(), []string{}, envValueFromToUpdate, envValueFromToRemove)
+	err = UpdateEnvVars(spec, args, util.NewOrderedMap(), []string{}, envValueFromToUpdate, envValueFromToRemove, "", util.NewOrderedMap(), []string{})
 	assert.NilError(t, err)
 	assert.DeepEqual(t, expected, spec.Containers[0].Env)
 }
@@ -162,7 +162,7 @@ func TestUpdateEnvVarsAllNew(t *testing.T) {
 	assert.NilError(t, err)
 	envValueFromToUpdate, envValueFromToRemove, err := util.OrderedMapAndRemovalListFromArray(argsEnvValueFrom, "=")
 	assert.NilError(t, err)
-	err = UpdateEnvVars(spec, args, envToUpdate, envToRemove, envValueFromToUpdate, envValueFromToRemove)
+	err = UpdateEnvVars(spec, args, envToUpdate, envToRemove, envValueFromToUpdate, envValueFromToRemove, "", util.NewOrderedMap(), []string{})
 	assert.NilError(t, err)
 	assert.DeepEqual(t, expected, spec.Containers[0].Env)
 }
@@ -197,7 +197,7 @@ func TestUpdateEnvVarsValueFromValidate(t *testing.T) {
 		args := append([]string{"command"}, input...)
 		envValueFromToUpdate, envValueFromToRemove, err := util.OrderedMapAndRemovalListFromArray(input, "=")
 		assert.NilError(t, err)
-		err = UpdateEnvVars(spec, args, util.NewOrderedMap(), []string{}, envValueFromToUpdate, envValueFromToRemove)
+		err = UpdateEnvVars(spec, args, util.NewOrderedMap(), []string{}, envValueFromToUpdate, envValueFromToRemove, "", util.NewOrderedMap(), []string{})
 		fmt.Println()
 		msg := fmt.Sprintf("input \"%s\" should fail, as it is not valid entry for containers.env.valueFrom", input[0])
 		assert.ErrorContains(t, err, " ", msg)
@@ -482,7 +482,7 @@ func TestUpdateEnvVarsModify(t *testing.T) {
 	args := append([]string{"command"}, argsEnv...)
 	envToUpdate, envToRemove, err := util.OrderedMapAndRemovalListFromArray(argsEnv, "=")
 	assert.NilError(t, err)
-	err = UpdateEnvVars(spec, args, envToUpdate, envToRemove, util.NewOrderedMap(), []string{})
+	err = UpdateEnvVars(spec, args, envToUpdate, envToRemove, util.NewOrderedMap(), []string{}, "", util.NewOrderedMap(), []string{})
 	assert.NilError(t, err)
 	assert.DeepEqual(t, expected, container.Env)
 }
@@ -516,7 +516,7 @@ func TestUpdateEnvVarsValueFromModify(t *testing.T) {
 	args := append([]string{"command"}, argsEnvValueFrom...)
 	envValueFromToUpdate, envValueFromToRemove, err := util.OrderedMapAndRemovalListFromArray(argsEnvValueFrom, "=")
 	assert.NilError(t, err)
-	err = UpdateEnvVars(spec, args, util.NewOrderedMap(), []string{}, envValueFromToUpdate, envValueFromToRemove)
+	err = UpdateEnvVars(spec, args, util.NewOrderedMap(), []string{}, envValueFromToUpdate, envValueFromToRemove, "", util.NewOrderedMap(), []string{})
 	assert.NilError(t, err)
 	assert.DeepEqual(t, expected, container.Env)
 }
@@ -557,7 +557,7 @@ func TestUpdateEnvVarsAllModify(t *testing.T) {
 	assert.NilError(t, err)
 	envValueFromToUpdate, envValueFromToRemove, err := util.OrderedMapAndRemovalListFromArray(argsEnvValueFrom, "=")
 	assert.NilError(t, err)
-	err = UpdateEnvVars(spec, args, envToUpdate, envToRemove, envValueFromToUpdate, envValueFromToRemove)
+	err = UpdateEnvVars(spec, args, envToUpdate, envToRemove, envValueFromToUpdate, envValueFromToRemove, "", util.NewOrderedMap(), []string{})
 	assert.NilError(t, err)
 	assert.DeepEqual(t, expected, container.Env)
 }
@@ -572,7 +572,7 @@ func TestUpdateEnvVarsRemove(t *testing.T) {
 	args := append([]string{"command"}, remove...)
 	envToUpdate, envToRemove, err := util.OrderedMapAndRemovalListFromArray(remove, "=")
 	assert.NilError(t, err)
-	err = UpdateEnvVars(spec, args, envToUpdate, envToRemove, util.NewOrderedMap(), []string{})
+	err = UpdateEnvVars(spec, args, envToUpdate, envToRemove, util.NewOrderedMap(), []string{}, "", util.NewOrderedMap(), []string{})
 	assert.NilError(t, err)
 
 	expected := []corev1.EnvVar{
@@ -606,7 +606,7 @@ func TestUpdateEnvVarsValueFromRemove(t *testing.T) {
 	args := append([]string{"command"}, remove...)
 	envValueFromToUpdate, envValueFromToRemove, err := util.OrderedMapAndRemovalListFromArray(remove, "=")
 	assert.NilError(t, err)
-	err = UpdateEnvVars(spec, args, util.NewOrderedMap(), []string{}, envValueFromToUpdate, envValueFromToRemove)
+	err = UpdateEnvVars(spec, args, util.NewOrderedMap(), []string{}, envValueFromToUpdate, envValueFromToRemove, "", util.NewOrderedMap(), []string{})
 	assert.NilError(t, err)
 
 	expected := []corev1.EnvVar{
@@ -659,7 +659,7 @@ func TestUpdateEnvVarsAllRemove(t *testing.T) {
 	assert.NilError(t, err)
 	envValueFromToUpdate, envValueFromToRemove, err := util.OrderedMapAndRemovalListFromArray(argsEnvValueFrom, "=")
 	assert.NilError(t, err)
-	err = UpdateEnvVars(spec, args, envToUpdate, envToRemove, envValueFromToUpdate, envValueFromToRemove)
+	err = UpdateEnvVars(spec, args, envToUpdate, envToRemove, envValueFromToUpdate, envValueFromToRemove, "", util.NewOrderedMap(), []string{})
 	assert.NilError(t, err)
 
 	expected := []corev1.EnvVar{

pkg/kn/flags/podspec_test.go

@@ -28,6 +28,7 @@ import (
 	"github.com/spf13/cobra"
 	"gotest.tools/v3/assert"
 	corev1 "k8s.io/api/core/v1"
+	v1 "k8s.io/api/core/v1"
 	"knative.dev/client/pkg/util"
 	"knative.dev/pkg/ptr"
 )
@@ -285,3 +286,45 @@ func TestPodSpecResolveReturnError(t *testing.T) {
 	out := outBuf.String()
 	assert.Assert(t, util.ContainsAll(out, "Invalid", "mount"))
 }
+
+func TestPodSpecResolveWithEnvFile(t *testing.T) {
+	file, err := ioutil.TempFile("", "envfile.env")
+	assert.NilError(t, err)
+	file.WriteString("svcOwner=James\nsvcAuthor=James")
+	defer os.Remove(file.Name())
+
+	inputArgs := []string{"--image", "repo/user/imageID:tag", "--env", "svcOwner=David",
+		"--env-file", file.Name(), "--port", "8080", "--cmd", "/app/start", "--arg", "myArg1"}
+	expectedPodSpec := corev1.PodSpec{
+		Containers: []corev1.Container{
+			{
+				Image:   "repo/user/imageID:tag",
+				Command: []string{"/app/start"},
+				Args:    []string{"myArg1"},
+				Ports: []corev1.ContainerPort{
+					{
+						ContainerPort: 8080,
+					},
+				},
+				Env: []corev1.EnvVar{{Name: "svcOwner", Value: "James"}, {Name: "svcAuthor", Value: "James"}},
+				Resources: v1.ResourceRequirements{
+					Limits:   v1.ResourceList{},
+					Requests: v1.ResourceList{},
+				},
+			},
+		},
+	}
+	flags := &PodSpecFlags{}
+	testCmd := &cobra.Command{
+		Use: "test",
+		Run: func(cmd *cobra.Command, args []string) {
+			podSpec := &corev1.PodSpec{Containers: []corev1.Container{{}}}
+			err := flags.ResolvePodSpec(podSpec, cmd.Flags(), inputArgs)
+			assert.NilError(t, err, "PodSpec cannot be resolved.")
+			assert.DeepEqual(t, expectedPodSpec, *podSpec)
+		},
+	}
+	testCmd.SetArgs(inputArgs)
+	flags.AddFlags(testCmd.Flags())
+	testCmd.Execute()
+}

pkg/util/parsing_helper.go

@@ -15,7 +15,9 @@
 package util
 
 import (
+	"bufio"
 	"fmt"
+	"os"
 	"strings"
 
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
@@ -23,6 +25,25 @@ import (
 	"knative.dev/pkg/tracker"
 )
 
+// GetEnvsFromFile transform a path to a file containing environment variable into a list of key-value pair.
+// If there is an issue reading the file or parsing the content in the file an error value will be returned.
+func GetEnvsFromFile(filepath string, delimiter string) ([]string, error) {
+	envs := []string{}
+	file, err := os.Open(filepath)
+	if err != nil {
+		return envs, err
+	}
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		line := scanner.Text()
+		if len(line) == 0 {
+			continue
+		}
+		envs = append(envs, scanner.Text())
+	}
+	return envs, nil
+}
+
 // OrderedMapAndRemovalListFromArray creates a list of key-value pair using MapFromArrayAllowingSingles, and a list of removal entries
 func OrderedMapAndRemovalListFromArray(arr []string, delimiter string) (*OrderedMap, []string, error) {
 	orderedMap := NewOrderedMap()

pkg/util/parsing_helper_test.go

@@ -16,6 +16,8 @@ package util
 
 import (
 	"fmt"
+	"io/ioutil"
+	"os"
 	"testing"
 
 	"gotest.tools/v3/assert"
@@ -186,3 +188,25 @@ func testToTrackerReference(t *testing.T, input, namespace string, expected *tra
 func funcRef(ref func(t *testing.T, err error)) *func(*testing.T, error) {
 	return &ref
 }
+
+func TestGetEnvsFromFile(t *testing.T) {
+	file, err := ioutil.TempFile("", "test-1")
+	assert.NilError(t, err)
+	file.WriteString(`
+name=service-1
+
+target=hello-world
+
+`)
+	defer os.Remove(file.Name())
+
+	envs, err := GetEnvsFromFile(file.Name(), "=")
+	assert.NilError(t, err)
+	assert.DeepEqual(t, envs, []string{"name=service-1", "target=hello-world"})
+}
+
+func TestGetEnvsFromFileErrorNotFound(t *testing.T) {
+	envs, err := GetEnvsFromFile("/tmp/somerandom/path/bla/bla", "=")
+	assert.ErrorContains(t, err, "no such file or directory")
+	assert.DeepEqual(t, envs, []string{})
+}