feature: add ohos_file_appender.

1) Add ohos_file_appender template for customizing passwd and group files.
Signed-off-by: Nhandyohos <zhangxiaotian@huawei.com>
Change-Id: Id7f6f791ad1a5cdedbfc1c9aac2f4e6376903f04

#I623HN

services/etc/appender/file_appender.gni

+# Copyright (c) 2021 Huawei Device Co., Ltd.
+# 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.
+
+import("//build/config/python.gni")
+import("//build/templates/common/copy.gni")
+
+# Append something (files or lines) to a file and install it.
+#
+# Variables:
+#  source: file to be appended (Required)
+#  deps: some targets deps on (Optional)
+#  output: the final install file name (Optional);
+#       If not set, it will install with the source file name
+#  files: files to be appended to the end of source file (Optional)
+#  lines: lines of strings to be appended to the end of souce file (Optional)
+#
+# Example:
+# ohos_file_appender("cust_passwd") {
+#   source = "//base/startup/init/services/etc/passwd"
+#   deps = [ "//base/startup/init/services/etc:passwd" ]
+#   files = [ "cust_passwd", "passwd2" ]
+#   lines = [ "tses::1222:1222:/bin/false", "tses2::1223:1223:/bin/false" ]
+#   output = "passwd"
+# }
+# It will append files and lines to source passwd file after deps targets
+#
+template("ohos_file_appender") {
+  assert(defined(invoker.source), "source full target name must be defined.")
+
+  _file_appender_target = "${target_name}_appended"
+
+  if (defined(invoker.output)) {
+    _final_install_name = get_path_info(invoker.output, "file")
+  } else {
+    _final_install_name = get_path_info(invoker.source, "file")
+  }
+
+  _appended_file =
+      target_gen_dir + "/${target_name}.appended/" + _final_install_name
+
+  action_with_pydeps(_file_appender_target) {
+    script = "//base/startup/init/services/etc/appender/file_appender.py"
+    depfile = "${target_gen_dir}/${target_name}.d"
+    if (defined(invoker.deps)) {
+      deps = invoker.deps
+    } else {
+      deps = []
+    }
+    args = [
+      "--output",
+      rebase_path(_appended_file, root_build_dir),
+      "--source-file",
+      rebase_path(invoker.source, root_build_dir),
+      "--depfile",
+      rebase_path(depfile, root_build_dir),
+    ]
+    if (defined(invoker.files)) {
+      foreach(file, invoker.files) {
+        args += [
+          "--append-file",
+          rebase_path(file, root_build_dir),
+        ]
+      }
+    }
+    if (defined(invoker.lines)) {
+      foreach(line, invoker.lines) {
+        args += [
+          "--append-line",
+          line,
+        ]
+      }
+    }
+    inputs = [ invoker.source ]
+    outputs = [ _appended_file ]
+  }
+
+  ohos_copy(target_name) {
+    forward_variables_from(invoker,
+                           [
+                             "testonly",
+                             "visibility",
+
+                             "deps",
+                             "public_configs",
+                             "subsystem_name",
+                             "part_name",
+
+                             # For generate_module_info
+                             "install_images",
+                             "module_install_dir",
+                             "relative_install_dir",
+                             "symlink_target_name",
+
+                             # Open source license related
+                             "license_file",
+                             "license_as_sources",
+                           ])
+    if (defined(deps)) {
+      deps += [ ":$_file_appender_target" ]
+    } else {
+      deps = [ ":$_file_appender_target" ]
+    }
+    set_sources_assignment_filter([])
+    sources = [ _appended_file ]
+    outputs = [ "${target_out_dir}/${target_name}/${_final_install_name}" ]
+    module_type = "etc"
+    install_enable = true
+    module_source_dir = "${target_out_dir}/${target_name}"
+    module_install_name = _final_install_name
+    if (defined(invoker.install_enable)) {
+      install_enable = invoker.install_enable
+    }
+  }
+}

services/etc/appender/file_appender.py

+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+# Copyright (c) 2021 Huawei Device Co., Ltd.
+# 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.
+
+import optparse
+import os
+import sys
+import stat
+import json
+
+
+def parse_args(args):
+    from scripts.util import build_utils  # noqa: E402
+
+    args = build_utils.expand_file_args(args)
+
+    parser = optparse.OptionParser()
+    build_utils.add_depfile_option(parser)
+    parser.add_option('--output', help='fixed para file')
+    parser.add_option('--source-file', help='source para file')
+    parser.add_option('--append-file', action="append", type="string", dest="files", help='appended files')
+    parser.add_option('--append-line', action="append", type="string", dest="lines", help='appended lines')
+
+    options, _ = parser.parse_args(args)
+    return options
+
+
+def append_files(target_f, options):
+    # Read source file
+    with open(options.source_file, 'r') as source_f:
+        source_contents = source_f.read()
+
+    target_f.write(source_contents)
+    if options.files:
+        for append_f in options.files:
+            with open(append_f, 'r') as src:
+                target_f.write(src.read())
+    if options.lines:
+        for line in options.lines:
+            target_f.write(line)
+            target_f.write("\n")
+
+
+def main(args):
+    sys.path.append(os.path.join(os.path.dirname(__file__), os.pardir, os.pardir,
+        os.pardir, os.pardir, os.pardir, os.pardir, "build"))
+    from scripts.util import build_utils  # noqa: E402
+
+    options = parse_args(args)
+
+    if options.files:
+        depfile_deps = ([options.source_file] + options.files)
+    else:
+        depfile_deps = ([options.source_file])
+
+    with os.fdopen(os.open(options.output, os.O_RDWR | os.O_CREAT, stat.S_IWUSR | stat.S_IRUSR), 'w') as target_f:
+        append_files(target_f, options)
+
+    build_utils.write_depfile(options.depfile,
+                options.output, depfile_deps, add_pydeps=False)
+
+
+if __name__ == '__main__':
+    sys.exit(main(sys.argv[1:]))

services/etc/appender/file_appender.pydeps

+# Generated by running:
+#   build/print_python_deps.py --root base/startup/init/services/etc/appender --output base/startup/init/services/etc/appender/file_appender.pydeps base/startup/init/services/etc/appender/file_appender.py
+../../../../../../build/gn_helpers.py
+../../../../../../build/scripts/__init__.py
+../../../../../../build/scripts/util/__init__.py
+../../../../../../build/scripts/util/build_utils.py
+../../../../../../build/scripts/util/md5_check.py
+../../../../../../build/scripts/util/pycache.py
+file_appender.py