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

cmd/config/internal/commands/run_test.go

@@ -204,6 +204,7 @@ apiVersion: v1
 				NetworkName:    "bridge",
 				EnableStarlark: true,
 				User:           "nobody",
+				Env:            []string{},
 			},
 		},
 		{
@@ -258,6 +259,7 @@ apiVersion: v1
 				NetworkName: "bridge",
 				ResultsDir:  "foo/",
 				User:        "nobody",
+				Env:         []string{},
 			},
 			expected: `
 metadata:
@@ -293,6 +295,28 @@ apiVersion: v1
 				Path:        "dir",
 				NetworkName: "bridge",
 				User:        "root",
+				Env:         []string{},
+			},
+			expected: `
+metadata:
+  name: function-input
+  annotations:
+    config.kubernetes.io/function: |
+      container: {image: 'foo:bar'}
+data: {}
+kind: ConfigMap
+apiVersion: v1
+`,
+		},
+		{
+			name: "specify env",
+			args: []string{"run", "dir", "--fn-env", "foo=bar", "--fn-env", "baz", "--image", "foo:bar"},
+			path: "dir",
+			expectedStruct: &runfn.RunFns{
+				Path:        "dir",
+				NetworkName: "bridge",
+				User:        "nobody",
+				Env:         []string{"foo=bar", "baz"},
 			},
 			expected: `
 metadata: