add --fn-env flag to fn run

cmd/config/internal/commands/run-fns.go

@@ -67,6 +67,9 @@ func GetRunFnRunner(name string) *RunFnRunner {
 		"a list of storage options read from the filesystem")
 	r.Command.Flags().StringVar(
 		&r.User, "fn-user", "nobody", "the username/uid used to run function in container")
+	r.Command.Flags().StringArrayVar(
+		&r.Env, "fn-env", []string{},
+		"a list of environment variables that will be exposed to container. Each item can be key=value pair or a key name of exported env.")
 	return r
 }
 
@@ -94,6 +97,7 @@ type RunFnRunner struct {
 	NetworkName        string
 	Mounts             []string
 	User               string
+	Env                []string
 }
 
 func (r *RunFnRunner) runE(c *cobra.Command, args []string) error {
@@ -309,6 +313,7 @@ func (r *RunFnRunner) preRunE(c *cobra.Command, args []string) error {
 		StorageMounts:  storageMounts,
 		ResultsDir:     r.ResultsDir,
 		User:           runtimeutil.ContainerUser(r.User),
+		Env:            r.Env,
 	}
 
 	// don't consider args for the function