The new `testutil.mock_command` context manager can be used to
mock commands in PATH and replace them with arbitrary shell
scripts. This is useful in testing to e.g. simulate exact error
conditions that would be hard to trigger otherwise or to replace
long running commands with faked results.
Example:
```
fake_cmd = textwrap.dedent("""\
do-something
""")
with mock_command("some-cmd", fake_cmd):
your_code
```
This commit reworks the `org.osbuild.container-deploy` stage to
not use a tmp storage when mounting the container image. This
is needed because of [0] but it should generally be fine because
inside the stages the real /var is a tmpfs (which is why we
triggered the bug in the first place).
[0] https://github.com/containers/storage/issues/1779
Extract a new helper `make_fake_tree()` that generalizes the existing
helper `make_fake_input_tree()`. The later will always create the
content under `{basedir}/tree` which is convinient for input tree
based tests but too specialized when using it in different contexts.
The existing `make_fake_input_tree()` is preserved unchanged and
becomes just a tiny wrapper.
This is a convenient way for tests to assert that some nested dicts
(like a parsed json) has a particular key/value somewhere in it.
For example:
assert_dict_has(config, "toplevel.subitem.key", True)
This commit adds `osbuild.testutil.imports.import_module_from_path`
that can be used to import arbitrary python source files. This
allows importing files from the stages directory that have a
non python friendly filename like `org.osbuild.kickstart`.
