add --fn-user flag to function run

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

@@ -65,6 +65,8 @@ func GetRunFnRunner(name string) *RunFnRunner {
 	r.Command.Flags().StringArrayVar(
 		&r.Mounts, "mount", []string{},
 		"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")
 	return r
 }
 
@@ -91,6 +93,7 @@ type RunFnRunner struct {
 	Network            bool
 	NetworkName        string
 	Mounts             []string
+	User               string
 }
 
 func (r *RunFnRunner) runE(c *cobra.Command, args []string) error {
@@ -305,6 +308,7 @@ func (r *RunFnRunner) preRunE(c *cobra.Command, args []string) error {
 		EnableExec:     r.EnableExec,
 		StorageMounts:  storageMounts,
 		ResultsDir:     r.ResultsDir,
+		User:           runtimeutil.ContainerUser(r.User),
 	}
 
 	// don't consider args for the function

cmd/config/internal/commands/run_test.go

@@ -203,6 +203,7 @@ apiVersion: v1
 				Path:           "dir",
 				NetworkName:    "bridge",
 				EnableStarlark: true,
+				User:           "nobody",
 			},
 		},
 		{
@@ -256,6 +257,7 @@ apiVersion: v1
 				Path:        "dir",
 				NetworkName: "bridge",
 				ResultsDir:  "foo/",
+				User:        "nobody",
 			},
 			expected: `
 metadata:
@@ -283,6 +285,26 @@ apiVersion: v1
 			args: []string{"run", "dir", "--image", "foo:bar", "--", "a=b", "c", "e=f"},
 			err:  "must have keys and values separated by",
 		},
+		{
+			name: "specify username",
+			args: []string{"run", "dir", "--fn-user", "root", "--image", "foo:bar"},
+			path: "dir",
+			expectedStruct: &runfn.RunFns{
+				Path:        "dir",
+				NetworkName: "bridge",
+				User:        "root",
+			},
+			expected: `
+metadata:
+  name: function-input
+  annotations:
+    config.kubernetes.io/function: |
+      container: {image: 'foo:bar'}
+data: {}
+kind: ConfigMap
+apiVersion: v1
+`,
+		},
 	}
 
 	for i := range tests {