Common Man Page Options
=======================

This subdirectory contains option (flag) names and descriptions
common to multiple podman man pages. Each file is one option. The
filename does not necessarily need to be identical to the option
name: for instance, `hostname.container.md` and `hostname.pod.md`
exist because the **--hostname** option is sufficiently different
between `podman-{create,run}` and `podman-pod-{create,run}` to
warrant living separately.

How
===

The files here are included in `podman-*.md.in` files using the `@@option`
mechanism:

```
@@option foo           ! includes options/foo.md
@@option quadlet:foo   ! includes options/foo.md with `is_quadlet=True`
                       ! See "Jinja2 Templating" below.
```

The tool that does this is `hack/markdown-preprocess`. It is a python
script because it needs to run on `readthedocs.io`. From a given `.md.in`
file, this script creates a `.md` file that can then be read by
`go-md2man`, `sphinx`, anything that groks markdown. This runs as
part of `make docs`.

Jinja2 Templating
=================

Some options are used as both Podman command line option and Quadlet
option. To reduce the duplication, the Jinja2 templating system can be
used to define parts which should be rendered only in Quadlet man-pages:

```
    << if is_quadlet >>
    ### `DNS=`
    << else >>
    #### **--dns**=*ipaddr*
    << endif >>
```

It is also possible to use in-line condition:

```
    << '**DNS=.**' if is_quadlet else '**--dns**' >>
```

Following variables are available for Jinja2 Templates:

- `is_quadlet`: True if file is imported using `@@option quadlet:foo`.
- `subcommand`: Same as `<<subcommand>>`, see below.
This allows the shared use of examples in the option file:
- `fullcommand`: Same as `<<fullsubcommand>>`, see below.

For more information about Jinja2, check
https://jinja.palletsprojects.com/en/stable/.

Special Substitutions
=====================

Some options are almost identical except for 'pod' vs 'container'
differences. For those, use `<<text for pods|text for containers>>`.
Order is immaterial: the important thing is the presence of the
string "`pod`" in one half but not the other. The correct string
is chosen based on the filename: if the file contains `-pod`,
such as `podman-pod-create`, the string with `pod` (case-insensitive)
in it is chosen.

The string `<<subcommand>>` is replaced with the podman subcommand
as determined from the filename, e.g., `create` for `podman-create.1.md.in`.
This allows the shared use of examples in the option file:
```
    Example: podman <<subcommand>> --foo --bar
```
As a special case, `podman-pod-X` becomes just `X` (the "pod" is removed).
This makes the `pod-id-file` man page more useful. To get the full
subcommand including 'pod', use `<<fullsubcommand>>`.

Restrictions
============

There is a restriction for having a single text line with three
back-ticks in the front and the end of the line.  For instance:

\`\`\`Some man page text\`\`\`

This is currently not allowed and causes a corruption of the
compiled man page.  Instead, put the three back-ticks on separate
lines like:

\`\`\`
Some man page text
\`\`\`