I had this after reading #12537 and #9047. Currently `DockerOperator`’s `volumes` argument is passed directly to docker-py’s `bind` (aka `docker -v`). But `-v`’s behaviour has long been problematic, and [Docker has been pushing users to the new `--mount` syntax instead](https://docs.docker.com/storage/bind-mounts/#choose-the--v-or---mount-flag). With #12537, it seems like `-v`’s behaviour is also confusing to some Airflow users, so I want to migrate Airflow’s internals to `--mount`.

However, `--mount` has a different syntax to `-v`, and the behaviour is also slightly different, so for compatibility reasons we can’t just do it under the hood. I can think of two possible solutions to this:

A. Deprecate `volumes` altogether and introduce `DockerOperator(mounts=...)`

This will emit a deprecation warning when the user passes `DockerOperator(volumes=...)` to tell them to convert to `DockerOperator(mounts=...)` instead. `volumes` will stay unchanged otherwise, and continue to be passed to bind mounts.

`mounts` will take a list of [`docker.types.Mount`](https://docker-py.readthedocs.io/en/stable/api.html#docker.types.Mount) to describe the mounts. They will be passed directly to the mounts API. Some shorthands could be useful as well, for example:

```python
DockerOperator(
    ...
    mounts=[
        ('/root/data1', './data1'),  # Source and target, default to volume mount.
        ('/root/data2', './data2', 'bind'),  # Bind mount.
    ],
)
```

B. Reuse `volumes` and do introspection to choose between binds and mounts

The `volumes` argument can be augmented to also accept `docker.types.Mount` instances, and internally we’ll do something like

```python
binds = []
mounts = []
for vol in volumes:
    if isinstance(vol, str):
        binds.append(vol)
    elif isintance(vol, docker.types.Mount):
        mounts.append(vol)
    else:
        raise ValueError('...')
if binds:
    warnings.warn('...', DeprecationWarning)
```

and pass the collected lists to binds and mounts respectively.

I’m very interested in hearing thoughts on this.


**Are you willing to submit a PR?**
Yes

**Related Issues**

* #12537: Confusing on the bind syntax.
* #9047: Implement mounting in `DockerSwarmOperator` (it’s a subclass of `DockerOperator`, but the `volumes` option is currently unused).

docs/conf.py
{
                        "section": section_name,
                        "name": prefixed_name,
                        "description": schema["description"],
                        "default": _format_default(schema["default"]),
                        "examples": _format_examples(param_name, schema),
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                )
            if schema.get("properties"):
                out += _get_params(schema["properties"], prefixed_name, section_name)
        return out
    schema_file = os.path.join(PACKAGE_DIR, "values.schema.json")  # 
    with open(schema_file) as config_file:
        chart_schema = json.load(config_file)
    params = _get_params(chart_schema["properties"])
    # 
    sections: Dict[str, List[Dict[str, str]]] = {}
    for param in params:
        if param["section"] not in sections:
            sections[param["section"]] = []
        sections[param["section"]].append(param)
    # 
    for section in sections.values():  # 
        section.sort(key=lambda i: i["name"])  # 
    # 
    ordered_sections = []
    for name in chart_schema["x-docsSectionOrder"]:
        if name not in sections:
            raise ValueError(f"Unable to find any parameters for section: {name}")
        ordered_sections.append({"name": name, "params": sections.pop(name)})