Fix USER handling. There were two issues:

- We were validating usernames/groupnames existed in etc/passwd. Docker does not do this
- We were incorrectly caching USER commands. This was fixed automatically by fixing the first part.

integration/dockerfiles/Dockerfile_test_user

@@ -0,0 +1,17 @@
+# Copyright 2018 Google, Inc. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+FROM gcr.io/google-appengine/debian9@sha256:1d6a9a6d106bd795098f60f4abb7083626354fa6735e81743c7f8cfca11259f0
+USER testuser:testgroup
+

pkg/commands/user.go

@@ -31,10 +31,6 @@ type UserCommand struct {
  cmd *instructions.UserCommand
 }
 
-func (r *UserCommand) RequiresUnpackedFS() bool {
- return true
-}
-
 func (r *UserCommand) ExecuteCommand(config *v1.Config, buildArgs *dockerfile.BuildArgs) error {
  logrus.Info("cmd: USER")
  u := r.cmd.User
@@ -52,11 +48,6 @@ func (r *UserCommand) ExecuteCommand(config *v1.Config, buildArgs *dockerfile.Bu
  }
  }
 
- _, _, err = util.GetUserFromUsername(userStr, groupStr)
- if err != nil {
- return err
- }
-
  if groupStr != "" {
  userStr = userStr + ":" + groupStr
  }

pkg/commands/user_test.go

@@ -28,57 +28,42 @@ import (
 var userTests = []struct {
  user string
  expectedUID string
- shouldError bool
 }{
  {
  user: "root",
  expectedUID: "root",
- shouldError: false,
  },
  {
  user: "0",
  expectedUID: "0",
- shouldError: false,
  },
  {
  user: "fakeUser",
- expectedUID: "",
- shouldError: true,
+ expectedUID: "fakeUser",
  },
  {
  user: "root:root",
  expectedUID: "root:root",
- shouldError: false,
  },
  {
  user: "0:root",
  expectedUID: "0:root",
- shouldError: false,
  },
  {
  user: "root:0",
  expectedUID: "root:0",
- shouldError: false,
  },
  {
  user: "0:0",
  expectedUID: "0:0",
- shouldError: false,
- },
- {
- user: "root:fakeGroup",
- expectedUID: "",
- shouldError: true,
  },
  {
  user: "$envuser",
  expectedUID: "root",
- shouldError: false,
  },
  {
  user: "root:$envgroup",
  expectedUID: "root:root",
- shouldError: false,
  },
 }
 
@@ -97,6 +82,6 @@ func TestUpdateUser(t *testing.T) {
  }
  buildArgs := dockerfile.NewBuildArgs([]string{})
  err := cmd.ExecuteCommand(cfg, buildArgs)
- testutil.CheckErrorAndDeepEqual(t, test.shouldError, err, test.expectedUID, cfg.User)
+ testutil.CheckErrorAndDeepEqual(t, false, err, test.expectedUID, cfg.User)
  }
 }