/usr/share/doc/cloud-init/examples
Edit: /usr/share/doc/cloud-init/examples/part-handler.txt (2081B)
#part-handler
"""This is a trivial example part-handler that creates a file with the path
specified in the payload. It performs no input checking or error handling.
To use it, first save the file you are currently viewing into your current
working directory. Then run the following:
```
$ echo '/var/tmp/my_path' > part
$ cloud-init devel make-mime -a part-handler.py:part-handler -a part:x-my-path --force > user-data
```
This will create a mime file with the contents of 'part' and the
part-handler. You can now pass 'user-data' to your cloud of choice.
When run, cloud-init will have created an empty file at /var/tmp/my_path.
"""
import pathlib
from typing import Any
from cloudinit.cloud import Cloud
def list_types():
"""Return a list of mime-types that are handled by this module."""
return ["text/x-my-path"]
def handle_part(data: Cloud, ctype: str, filename: str, payload: Any):
"""Handle a part with the given mime-type.
This function will get called multiple times. The first time is
to allow any initial setup needed to handle parts. It will then get
called once for each part matching the mime-type returned by `list_types`.
Finally, it will get called one last time to allow for any final
teardown.
:data: A `Cloud` instance. This will be the same instance for each call
to handle_part.
:ctype: '__begin__', '__end__', or the mime-type
(for this example 'text/x-my-path') of the part
:filename: The filename for the part as defined in the MIME archive,
or dynamically generated part if no filename is given
:payload: The content of the part. This will be
`None` when `ctype` is '__begin__' or '__end__'.
"""
if ctype == "__begin__":
# Any custom setup needed before handling payloads
return
if ctype == "__end__":
# Any custom teardown needed after handling payloads can happen here
return
# If we've made it here, we're dealing with a real payload, so handle
# it appropriately
pathlib.Path(payload.strip()).touch()