podman/pkg/hooks
Sascha Grunert a46f798831
pkg: switch to golang native error wrapping
We now use the golang error wrapping format specifier `%w` instead of
the deprecated github.com/pkg/errors package.

[NO NEW TESTS NEEDED]

Signed-off-by: Sascha Grunert <sgrunert@redhat.com>
2022-07-08 08:54:47 +02:00
..
0.1.0 bump go module to version 4 2022-01-18 12:47:07 +01:00
1.0.0 pkg: switch to golang native error wrapping 2022-07-08 08:54:47 +02:00
docs [CI:DOCS] oci-hooks.5.md: fixup section in header 2021-10-10 08:16:42 -04:00
exec pkg: switch to golang native error wrapping 2022-07-08 08:54:47 +02:00
README.md Spelling 2020-12-22 13:34:31 -05:00
hooks.go pkg: switch to golang native error wrapping 2022-07-08 08:54:47 +02:00
hooks_test.go test: use `T.TempDir` to create temporary test directory 2022-05-05 21:09:41 +08:00
monitor.go bump go module to version 4 2022-01-18 12:47:07 +01:00
monitor_test.go test: use `T.TempDir` to create temporary test directory 2022-05-05 21:09:41 +08:00
read.go pkg: switch to golang native error wrapping 2022-07-08 08:54:47 +02:00
read_test.go test: use `T.TempDir` to create temporary test directory 2022-05-05 21:09:41 +08:00
version.go pkg/hooks: Version the hook structure and add 1.0.0 hooks 2018-05-11 16:26:35 +00:00

README.md

OCI Hooks Configuration

For POSIX platforms, the OCI runtime configuration supports hooks for configuring custom actions related to the life cycle of the container. The way you enable the hooks above is by editing the OCI runtime configuration before running the OCI runtime (e.g. runc). CRI-O and podman create create the OCI configuration for you, and this documentation allows developers to configure them to set their intended hooks.

One problem with hooks is that the runtime actually stalls execution of the container before running the hooks and stalls completion of the container, until all hooks complete. This can cause some performance issues. Also a lot of hooks just check if certain configuration is set and then exit early, without doing anything. For example the oci-systemd-hook only executes if the command is init or systemd, otherwise it just exits. This means if we automatically enabled all hooks, every container would have to execute oci-systemd-hook, even if they don't run systemd inside of the container. Performance would also suffer if we executed each hook at each stage (pre-start, post-start, and post-stop).

The hooks configuration is documented in oci-hooks.5.