Allow adjusting number of locks in libpod.conf via an already
available knob we previously didn't expose in the default config
file.
Signed-off-by: Matthew Heon <matthew.heon@pm.me>
There's been a lot of discussion over in [1] about how to support the
NVIDIA folks and others who want to be able to create devices
(possibly after having loaded kernel modules) and bind userspace
libraries into the container. Currently that's happening in the
middle of runc's create-time mount handling before the container
pivots to its new root directory with runc's incorrectly-timed
prestart hook trigger [2]. With this commit, we extend hooks with a
'precreate' stage to allow trusted parties to manipulate the config
JSON before calling the runtime's 'create'.
I'm recycling the existing Hook schema from pkg/hooks for this,
because we'll want Timeout for reliability and When to avoid the
expense of fork/exec when a given hook does not need to make config
changes [3].
[1]: https://github.com/opencontainers/runc/pull/1811
[2]: https://github.com/opencontainers/runc/issues/1710
[3]: https://github.com/containers/libpod/issues/1828#issuecomment-439888059
Signed-off-by: W. Trevor King <wking@tremily.us>
Add support for executing an init binary as PID 1 in a container to
forward signals and reap processes. When the `--init` flag is set for
podman-create or podman-run, the init binary is bind-mounted to
`/dev/init` in the container and "/dev/init --" is prepended to the
container's command.
The default base path of the container-init binary is `/usr/libexec/podman`
while the default binary is catatonit [1]. This default can be changed
permanently via the `init_path` field in the `libpod.conf` configuration
file (which is recommended for packaging) or temporarily via the
`--init-path` flag of podman-create and podman-run.
[1] https://github.com/openSUSE/catatonitFixes: #1670
Signed-off-by: Valentin Rothberg <rothberg@redhat.com>
Part of the motivation for 800eb863 (Hooks supports two directories,
process default and override, 2018-09-17, #1487) was [1]:
> We only use this for override. The reason this was caught is people
> are trying to get hooks to work with CoreOS. You are not allowed to
> write to /usr/share... on CoreOS, so they wanted podman to also look
> at /etc, where users and third parties can write.
But we'd also been disabling hooks completely for rootless users. And
even for root users, the override logic was tricky when folks actually
had content in both directories. For example, if you wanted to
disable a hook from the default directory, you'd have to add a no-op
hook to the override directory.
Also, the previous implementation failed to handle the case where
there hooks defined in the override directory but the default
directory did not exist:
$ podman version
Version: 0.11.2-dev
Go Version: go1.10.3
Git Commit: "6df7409cb5a41c710164c42ed35e33b28f3f7214"
Built: Sun Dec 2 21:30:06 2018
OS/Arch: linux/amd64
$ ls -l /etc/containers/oci/hooks.d/test.json
-rw-r--r--. 1 root root 184 Dec 2 16:27 /etc/containers/oci/hooks.d/test.json
$ podman --log-level=debug run --rm docker.io/library/alpine echo 'successful container' 2>&1 | grep -i hook
time="2018-12-02T21:31:19-08:00" level=debug msg="reading hooks from /usr/share/containers/oci/hooks.d"
time="2018-12-02T21:31:19-08:00" level=warning msg="failed to load hooks: {}%!(EXTRA *os.PathError=open /usr/share/containers/oci/hooks.d: no such file or directory)"
With this commit:
$ podman --log-level=debug run --rm docker.io/library/alpine echo 'successful container' 2>&1 | grep -i hook
time="2018-12-02T21:33:07-08:00" level=debug msg="reading hooks from /usr/share/containers/oci/hooks.d"
time="2018-12-02T21:33:07-08:00" level=debug msg="reading hooks from /etc/containers/oci/hooks.d"
time="2018-12-02T21:33:07-08:00" level=debug msg="added hook /etc/containers/oci/hooks.d/test.json"
time="2018-12-02T21:33:07-08:00" level=debug msg="hook test.json matched; adding to stages [prestart]"
time="2018-12-02T21:33:07-08:00" level=warning msg="implicit hook directories are deprecated; set --hooks-dir="/etc/containers/oci/hooks.d" explicitly to continue to load hooks from this directory"
time="2018-12-02T21:33:07-08:00" level=error msg="container create failed: container_linux.go:336: starting container process caused "process_linux.go:399: container init caused \"process_linux.go:382: running prestart hook 0 caused \\\"error running hook: exit status 1, stdout: , stderr: oh, noes!\\\\n\\\"\""
(I'd setup the hook to error out). You can see that it's silenly
ignoring the ENOENT for /usr/share/containers/oci/hooks.d and
continuing on to load hooks from /etc/containers/oci/hooks.d.
When it loads the hook, it also logs a warning-level message
suggesting that callers explicitly configure their hook directories.
That will help consumers migrate, so we can drop the implicit hook
directories in some future release. When folks *do* explicitly
configure hook directories (via the newly-public --hooks-dir and
hooks_dir options), we error out if they're missing:
$ podman --hooks-dir /does/not/exist run --rm docker.io/library/alpine echo 'successful container'
error setting up OCI Hooks: open /does/not/exist: no such file or directory
I've dropped the trailing "path" from the old, hidden --hooks-dir-path
and hooks_dir_path because I think "dir(ectory)" is already enough
context for "we expect a path argument". I consider this name change
non-breaking because the old forms were undocumented.
Coming back to rootless users, I've enabled hooks now. I expect they
were previously disabled because users had no way to avoid
/usr/share/containers/oci/hooks.d which might contain hooks that
required root permissions. But now rootless users will have to
explicitly configure hook directories, and since their default config
is from ~/.config/containers/libpod.conf, it's a misconfiguration if
it contains hooks_dir entries which point at directories with hooks
that require root access. We error out so they can fix their
libpod.conf.
[1]: https://github.com/containers/libpod/pull/1487#discussion_r218149355
Signed-off-by: W. Trevor King <wking@tremily.us>
Also update some missing fields libpod.conf obtions in man pages.
Fix sort order of security options and add a note about disabling
labeling.
When a process requests a new label. libpod needs to reserve all
labels to make sure that their are no conflicts.
Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>
Closes: #1406
Approved by: mheon
Base heading is level 2, which is identical to the level 1. However
level 3 will be indendet which is used a lot in the `## EXAMPLES`
sections.
Signed-off-by: Valentin Rothberg <vrothberg@suse.com>
Closes: #1375
Approved by: rhatdan
- second heading
- consistent mail addresses <user@domain.com>
- change order with latest changes first
Signed-off-by: Valentin Rothberg <vrothberg@suse.com>
Closes: #1375
Approved by: rhatdan
Format md files to work properly when converted to man pages.
Add sed command to cleanup table in podman man page.
Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>
Closes: #842
Approved by: mheon
Matthew Heon