Parse build-args for empty values (#517)

* Parse build-args for empty values
* Split for first equal sign in build-args
* Honor empty values in build-args

Fixes: #514

Signed-off-by: Abhijeet Kasurde <akasurde@redhat.com>

docs/usage.rst

@@ -142,6 +142,12 @@ By default, the Containerfile / Dockerfile outputted by Ansible Builder contains
 
    $ ansible-builder build --build-arg FOO=bar
 
+To use different build arguments, you can specify ``--build-arg`` multiple times:
+
+.. code::
+
+   $ ansible-builder build --build-arg FOO=bar --build-arg SIMPLE=sample
+
 To use a custom base image:
 
 .. code::
@@ -249,7 +255,7 @@ Examples
 
 The example in ``test/data/pytz`` requires the ``awx.awx`` collection in
 the execution environment definition. The lookup plugin
-``awx.awx.tower_schedule_rrule`` requires the PyPI ``pytz`` and another
+``awx.awx.schedule_rrule`` requires the PyPI ``pytz`` and another
 library to work. If ``test/data/pytz/execution-environment.yml`` file is
 given to the ``ansible-builder build`` command, then it will install the
 collection inside the image, read ``requirements.txt`` inside of the
@@ -269,7 +275,7 @@ the private data directory.
 
 The ``awx.awx`` collection is a subset of content included in the default
 AWX execution environment. More details can be found at the
-`awx-ee <https://github.com/ansible/awx-ee>`__ repository.
+`awx-ee <https://github.com/ansible/awx-ee>`_ repository.
 
 
 Deprecated Features

src/ansible_builder/cli.py

@@ -202,13 +202,15 @@ def parse_args(args=sys.argv[1:]):
 
 class BuildArgAction(argparse.Action):
     def __call__(self, parser, namespace, values, option_string=None):
-        key, *value = values.split('=')
+        key, sep, value = values.partition("=")
         attr = getattr(namespace, self.dest)
 
         # None signifies that the build-arg will come from the environment.
         # This is currently only supported by Docker. Podman will treat any
         # usage of the $VALUE as a literal string.
         if value:
-            attr[key] = value[0]
+            attr[key] = value
+        elif sep == '=' and value == '':
+            attr[key] = ''
         else:
             attr[key] = None

test/unit/test_cli.py

@@ -38,6 +38,36 @@ def test_custom_ansible_galaxy_cli_role_opts(exec_env_definition_file, tmp_path)
     assert aee.build_args == {'ANSIBLE_GALAXY_CLI_ROLE_OPTS': '--ignore-errors'}
 
 
+def test_build_args_empty_value(exec_env_definition_file, tmp_path):
+    content = {'version': 3}
+    path = str(exec_env_definition_file(content=content))
+
+    aee = prepare(['build', '-f', path, '--build-arg', 'ANSIBLE_GALAXY_CLI_ROLE_OPTS=', '-c', str(tmp_path)])
+    assert aee.build_args == {'ANSIBLE_GALAXY_CLI_ROLE_OPTS': ''}
+
+
+def test_build_args_no_trailing_equal(exec_env_definition_file, tmp_path):
+    content = {'version': 3}
+    path = str(exec_env_definition_file(content=content))
+
+    aee = prepare(['build', '-f', path, '--build-arg', 'ANSIBLE_GALAXY_CLI_ROLE_OPTS', '-c', str(tmp_path)])
+    assert aee.build_args == {'ANSIBLE_GALAXY_CLI_ROLE_OPTS': None}
+
+
+def test_build_args_multiple_equal_sign_value(exec_env_definition_file, tmp_path):
+    content = {'version': 3}
+    path = str(exec_env_definition_file(content=content))
+
+    aee = prepare(['build', '-f', path,
+                   '--build-arg', 'ANSIBLE_GALAXY_CLI_ROLE_OPTS=',
+                   '--build-arg', 'PYTHON_CONFIG_SETTINGS=--config-setting=--global-option=--tag-build=SUFFIX',
+                   '-c', str(tmp_path)])
+    assert aee.build_args == {
+        'PYTHON_CONFIG_SETTINGS': '--config-setting=--global-option=--tag-build=SUFFIX',
+        'ANSIBLE_GALAXY_CLI_ROLE_OPTS': ''
+    }
+
+
 def test_build_context(good_exec_env_definition_path, tmp_path):
     path = str(good_exec_env_definition_path)
     build_context = str(tmp_path)