Man pages: refactor common options: --volume

This one is a nightmare, because --volume has been edited
in four different files throughout the years (five if you
count podman-build, which I am not including in this PR).
Those edits have not always been done in sync.

The list of options was reordered 2022-06-28 by Giuseppe in #14734,
but only in podman-create and -run (not in podman-pod-*). No
explanation of why, but I'll assume he knew what he was doing,
and have accepted that for the reference copy.

There was also a big edit in #8519.

The "Propagation property...bind mounted" sentence first appeared
in pod-clone, in #14299 by cdoern, with no obvious source of where
it came from. I choose to include it in the reference copy.

The "**copy**" option seems to work in pod-create, so I'm including
it in the reference copy. Someone please yell loudly if this is
not the case.

The "disables SELinux separation for containers used in the build",
no idea, changed that to just "for the container/pod"

The "advanced users / overlay / upperdir / workdir" paragraph
makes zero sense to me, but hey, I assume it applies to all
the commands, so I put it in the reference copy.

Finally, there's still a mishmash of backticks, asterisks, underscores,
and even quotation marks. Someone is gonna have to perform major
cleanup on this one day, but at least it'll be in only one place.

Signed-off-by: Ed Santiago <santiago@redhat.com>

1 files changed, 2 insertions, 172 deletions

diff --git a/docs/source/markdown/podman-run.1.md.in b/docs/source/markdown/podman-run.1.md.in
index 86066ad9c..493a7494a 100644
--- a/docs/source/markdown/podman-run.1.md.in
+++ b/docs/source/markdown/podman-run.1.md.in
@@ -584,179 +584,9 @@ When a user namespace is not in use, the UID and GID used within the container a
 #### **--variant**=*VARIANT*
 Use _VARIANT_ instead of the default architecture variant of the container image. Some images can use multiple variants of the arm architectures, such as arm/v5 and arm/v7.
 
-#### **--volume**, **-v**=*[[SOURCE-VOLUME|HOST-DIR:]CONTAINER-DIR[:OPTIONS]]*
+@@option volume
 
-Create a bind mount. If you specify _/HOST-DIR_:_/CONTAINER-DIR_, Podman
-bind mounts _host-dir_ in the host to _CONTAINER-DIR_ in the Podman
-container. Similarly, _SOURCE-VOLUME_:_/CONTAINER-DIR_ will mount the volume
-in the host to the container. If no such named volume exists, Podman will
-create one. (Note when using the remote client, including Mac and Windows (excluding WSL2) machines, the volumes will be mounted from the remote server, not necessarily the client machine.)
-
-The _options_ is a comma-separated list and can be: <sup>[[1]](#Footnote1)</sup>
-
-* **rw**|**ro**
-* **z**|**Z**
-* [**O**]
-* [**U**]
-* [**no**]**copy**
-* [**no**]**dev**
-* [**no**]**exec**
-* [**no**]**suid**
-* [**r**]**bind**
-* [**r**]**shared**|[**r**]**slave**|[**r**]**private**[**r**]**unbindable**
-
-The `CONTAINER-DIR` must be an absolute path such as `/src/docs`. The volume
-will be mounted into the container at this directory.
-
-Volumes may specify a source as well, as either a directory on the host
-or the name of a named volume. If no source is given, the volume will be created as an
-anonymously named volume with a randomly generated name, and will be removed when
-the container is removed via the `--rm` flag or `podman rm --volumes`.
-
-If a volume source is specified, it must be a path on the host or the name of a
-named volume. Host paths are allowed to be absolute or relative; relative paths
-are resolved relative to the directory Podman is run in. If the source does not
-exist, Podman will return an error. Users must pre-create the source files or
-directories.
-
-Any source that does not begin with a `.` or `/` will be treated as the name of
-a named volume. If a volume with that name does not exist, it will be created.
-Volumes created with names are not anonymous, and they are not removed by the `--rm`
-option and the `podman rm --volumes` command.
-
-You can specify multiple **-v** options to mount one or more volumes into a
-container.
-
-  `Write Protected Volume Mounts`
-
-You can add **:ro** or **:rw** option to mount a volume in read-only or
-read-write mode, respectively. By default, the volumes are mounted read-write.
-
-  `Chowning Volume Mounts`
-
-By default, Podman does not change the owner and group of source volume
-directories mounted into containers. If a container is created in a new user
-namespace, the UID and GID in the container may correspond to another UID and
-GID on the host.
-
-The `:U` suffix tells Podman to use the correct host UID and GID based on the
-UID and GID within the container, to change recursively the owner and group of
-the source volume.
-
-**Warning** use with caution since this will modify the host filesystem.
-
-  `Labeling Volume Mounts`
-
-Labeling systems like SELinux require that proper labels are placed on volume
-content mounted into a container. Without a label, the security system might
-prevent the processes running inside the container from using the content. By
-default, Podman does not change the labels set by the OS.
-
-To change a label in the container context, you can add either of two suffixes
-**:z** or **:Z** to the volume mount. These suffixes tell Podman to relabel file
-objects on the shared volumes. The **z** option tells Podman that two containers
-share the volume content. As a result, Podman labels the content with a shared
-content label. Shared volume labels allow all containers to read/write content.
-The **Z** option tells Podman to label the content with a private unshared label.
-
-Note: Do not relabel system files and directories. Relabeling system content
-might cause other confined services on your machine to fail.  For these types
-of containers we recommend disabling SELinux separation.  The option
-`--security-opt label=disable` disables SELinux separation for the container.
-For example if a user wanted to volume mount their entire home directory into a
-container, they need to disable SELinux separation.
-
-	   $ podman run --security-opt label=disable -v $HOME:/home/user fedora touch /home/user/file
-
-  `Overlay Volume Mounts`
-
-   The `:O` flag tells Podman to mount the directory from the host as a
-temporary storage using the `overlay file system`. The container processes
-can modify content within the mountpoint which is stored in the
-container storage in a separate directory. In overlay terms, the source
-directory will be the lower, and the container storage directory will be the
-upper. Modifications to the mount point are destroyed when the container
-finishes executing, similar to a tmpfs mount point being unmounted.
-
-  For advanced users overlay option also supports custom non-volatile `upperdir` and `workdir`
-for the overlay mount. Custom `upperdir` and `workdir` can be fully managed by the users themselves
-and `podman` will not remove it on lifecycle completion. Example `:O,upperdir=/some/upper,workdir=/some/work`
-
-  Subsequent executions of the container will see the original source directory
-content, any changes from previous container executions no longer exist.
-
-  One use case of the overlay mount is sharing the package cache from the
-host into the container to allow speeding up builds.
-
-  Note:
-
-     - The `O` flag conflicts with other options listed above.
-Content mounted into the container is labeled with the private label.
-       On SELinux systems, labels in the source directory must be readable
-by the container label. Usually containers can read/execute `container_share_t`
-and can read/write `container_file_t`. If you cannot change the labels on a
-source volume, SELinux container separation must be disabled for the container
-to work.
-     - The source directory mounted into the container with an overlay mount
-should not be modified, it can cause unexpected failures. It is recommended
-that you do not modify the directory until the container finishes running.
-
-Only the current container can use a private volume.
-
-  `Mounts propagation`
-
-By default bind mounted volumes are `private`. That means any mounts done
-inside container will not be visible on host and vice versa. One can change
-this behavior by specifying a volume mount propagation property. Making a
-volume shared mounts done under that volume inside container will be
-visible on host and vice versa. Making a volume **slave** enables only one
-way mount propagation and that is mounts done on host under that volume
-will be visible inside container but not the other way around. <sup>[[1]](#Footnote1)</sup>
-
-To control mount propagation property of a volume one can use the [**r**]**shared**,
-[**r**]**slave**, [**r**]**private** or the [**r**]**unbindable** propagation flag.
-For mount propagation to work the source mount point (the mount point where source dir
-is mounted on) has to have the right propagation properties. For shared volumes, the
-source mount point has to be shared. And for slave volumes, the source mount point
-has to be either shared or slave. <sup>[[1]](#Footnote1)</sup>
-
-If you want to recursively mount a volume and all of its submounts into a
-container, then you can use the **rbind** option. By default the bind option is
-used, and submounts of the source directory will not be mounted into the
-container.
-
-Mounting the volume with the **nosuid** options means that SUID applications on
-the volume will not be able to change their privilege. By default volumes
-are mounted with **nosuid**.
-
-Mounting the volume with the **noexec** option means that no executables on the
-volume will be able to be executed within the container.
-
-Mounting the volume with the **nodev** option means that no devices on the volume
-will be able to be used by processes within the container. By default volumes
-are mounted with **nodev**.
-
-If the _host-dir_ is a mount point, then **dev**, **suid**, and **exec** options are
-ignored by the kernel.
-
-Use **df $hostdir** to figure out the source mount, and then use
-**findmnt -o TARGET,PROPAGATION _source-mount-dir_** to figure out propagation
-properties of source mount. If **findmnt**(1) utility is not available, then one
-can look at mount entry for source mount point in _/proc/self/mountinfo_. Look
-at the "optional fields" and see if any propagation properties are specified.
-In there, **shared:N** means the mount is shared, **master:N** means mount
-is slave, and if nothing is there, the mount is private. <sup>[[1]](#Footnote1)</sup>
-
-To change propagation properties of a mount point, use **mount**(8) command. For
-example, if one wants to bind mount source directory _/foo_, one can do
-**mount --bind /foo /foo** and **mount --make-private --make-shared /foo**. This
-will convert /foo into a shared mount point. Alternatively, one can directly
-change propagation properties of source mount. Say, if _/_ is source mount for
-_/foo_, then use **mount --make-shared /** to convert _/_ into a shared mount.
-
-Note: if the user only has access rights via a group, accessing the volume
-from inside a rootless container will fail. Use the `--group-add keep-groups`
-flag to pass the user's supplementary group access into the container.
+Use the **--group-add keep-groups** option to pass the user's supplementary group access into the container.
 
 #### **--volumes-from**=*CONTAINER[:OPTIONS]*