From 63fd3a3fcaf320a3eede8878aba9b5636b8db6c8 Mon Sep 17 00:00:00 2001 From: Daniel J Walsh <dwalsh@redhat.com> Date: Mon, 26 Apr 2021 06:06:30 -0400 Subject: Add more documentation on conmon Signed-off-by: Daniel J Walsh <dwalsh@redhat.com> --- docs/source/markdown/podman-container-cleanup.1.md | 2 +- docs/source/markdown/podman-create.1.md | 16 +++++++++++++++- docs/source/markdown/podman-generate-systemd.1.md | 2 +- docs/source/markdown/podman-run.1.md | 16 +++++++++++++++- docs/source/markdown/podman.1.md | 2 +- 5 files changed, 33 insertions(+), 5 deletions(-) (limited to 'docs/source') diff --git a/docs/source/markdown/podman-container-cleanup.1.md b/docs/source/markdown/podman-container-cleanup.1.md index bd650c6af..9f9b90fc2 100644 --- a/docs/source/markdown/podman-container-cleanup.1.md +++ b/docs/source/markdown/podman-container-cleanup.1.md @@ -48,7 +48,7 @@ After cleanup, remove the image entirely. `podman container cleanup --latest` ## SEE ALSO -podman(1), podman-container(1) +**podman**(1), **podman-container**(1), **conmon**(8). ## HISTORY Jun 2018, Originally compiled by Dan Walsh <dwalsh@redhat.com> diff --git a/docs/source/markdown/podman-create.1.md b/docs/source/markdown/podman-create.1.md index 229bb82f5..c375f2417 100644 --- a/docs/source/markdown/podman-create.1.md +++ b/docs/source/markdown/podman-create.1.md @@ -1412,6 +1412,20 @@ $ podman start --attach ctr b ``` +## CONMON + +When Podman starts a container it actually executes the conmon program, which +then executes the OCI Runtime. Conmon is the container monitor. It is a small +program whose job is to watch the primary process of the container, and if the +container dies, save the exit code. It also holds open the tty of the +container, so that it can be attached to later. This is what allows Podman to +run in detached mode (backgrounded), so Podman can exit but conmon continues to +run. Each container has their own instance of conmon. Conmon waits for the +container to exit, gathers and saves the exit code, and then launches a Podman +process to complete the container cleanup, by shutting down the network and +storage. For more information on conmon, please reference the conmon(8) man +page. + ## FILES **/etc/subuid** @@ -1421,7 +1435,7 @@ NOTE: Use the environment variable `TMPDIR` to change the temporary storage loca ## SEE ALSO **podman**(1), **podman-secret**(1), **podman-save**(1), **podman-ps**(1), **podman-attach**(1), **podman-pod-create**(1), **podman-port**(1), **podman-start*(1), **podman-kill**(1), **podman-stop**(1), -**podman-generate-systemd**(1) **podman-rm**(1), **subgid**(5), **subuid**(5), **containers.conf**(5), **systemd.unit**(5), **setsebool**(8), **slirp4netns**(1), **fuse-overlayfs**(1), **proc**(5)**. +**podman-generate-systemd**(1) **podman-rm**(1), **subgid**(5), **subuid**(5), **containers.conf**(5), **systemd.unit**(5), **setsebool**(8), **slirp4netns**(1), **fuse-overlayfs**(1), **proc**(5), **conmon**(8). ## HISTORY October 2017, converted from Docker documentation to Podman by Dan Walsh for Podman `<dwalsh@redhat.com>` diff --git a/docs/source/markdown/podman-generate-systemd.1.md b/docs/source/markdown/podman-generate-systemd.1.md index 431163d56..1d427d35b 100644 --- a/docs/source/markdown/podman-generate-systemd.1.md +++ b/docs/source/markdown/podman-generate-systemd.1.md @@ -233,7 +233,7 @@ CONTAINER ID IMAGE COMMAND CREATED STATUS bb310a0780ae docker.io/library/alpine:latest /bin/sh 3 minutes ago Created busy_moser ``` ## SEE ALSO -[podman(1)](podman.1.md), [podman-container(1)](podman-container.1.md), systemctl(1), systemd.unit(5), systemd.service(5) +[**podman**(1)](podman.1.md), [**podman-container**(1)](podman-container.1.md), **systemctl**(1), **systemd.unit**(5), **systemd.service**(5), **conmon**(8). ## HISTORY April 2020, Updated details and added usecase to use generated .service files as root and non-root, by Sujil Shah (sushah at redhat dot com) diff --git a/docs/source/markdown/podman-run.1.md b/docs/source/markdown/podman-run.1.md index 2e6d97a05..74bbf8809 100644 --- a/docs/source/markdown/podman-run.1.md +++ b/docs/source/markdown/podman-run.1.md @@ -1763,6 +1763,20 @@ $ podman run --env ENV*****=b alpine printenv ENV***** b ``` +## CONMON + +When Podman starts a container it actually executes the conmon program, which +then executes the OCI Runtime. Conmon is the container monitor. It is a small +program whose job is to watch the primary process of the container, and if the +container dies, save the exit code. It also holds open the tty of the +container, so that it can be attached to later. This is what allows Podman to +run in detached mode (backgrounded), so Podman can exit but conmon continues to +run. Each container has their own instance of conmon. Conmon waits for the +container to exit, gathers and saves the exit code, and then launches a Podman +process to complete the container cleanup, by shutting down the network and +storage. For more information on conmon, please reference the conmon(8) man +page. + ## FILES **/etc/subuid** @@ -1773,7 +1787,7 @@ NOTE: Use the environment variable `TMPDIR` to change the temporary storage loca ## SEE ALSO **podman**(1), **podman-save**(1), **podman-ps**(1), **podman-attach**(1), **podman-pod-create**(1), **podman-port**(1), **podman-start**(1), **podman-kill**(1), **podman-stop**(1), -**podman-generate-systemd**(1) **podman-rm**(1), **subgid**(5), **subuid**(5), **containers.conf**(5), **systemd.unit**(5), **setsebool**(8), **slirp4netns**(1), **fuse-overlayfs**(1), **proc**(5)**. +**podman-generate-systemd**(1) **podman-rm**(1), **subgid**(5), **subuid**(5), **containers.conf**(5), **systemd.unit**(5), **setsebool**(8), **slirp4netns**(1), **fuse-overlayfs**(1), **proc**(5), **conmon**(8). ## HISTORY September 2018, updated by Kunal Kushwaha `<kushwaha_kunal_v7@lab.ntt.co.jp>` diff --git a/docs/source/markdown/podman.1.md b/docs/source/markdown/podman.1.md index 87bcd8802..3b90a0922 100644 --- a/docs/source/markdown/podman.1.md +++ b/docs/source/markdown/podman.1.md @@ -343,7 +343,7 @@ The Network File System (NFS) and other distributed file systems (for example: L For more information, please refer to the [Podman Troubleshooting Page](https://github.com/containers/podman/blob/master/troubleshooting.md). ## SEE ALSO -`containers-mounts.conf(5)`, `containers-registries.conf(5)`, `containers-storage.conf(5)`, `buildah(1)`, `containers.conf(5)`, `oci-hooks(5)`, `containers-policy.json(5)`, `crun(8)`, `runc(8)`, `subuid(5)`, `subgid(5)`, `slirp4netns(1)` +**containers-mounts.conf**(5), **containers-registries.conf**(5), **containers-storage.conf**(5), **buildah**(1), **containers.conf**(5), **oci-hooks**(5), **containers-policy.json**(5), **crun**(8), **runc**(8), **subuid**(5), **subgid**(5), **slirp4netns**(1), **conmon**(8). ## HISTORY Dec 2016, Originally compiled by Dan Walsh <dwalsh@redhat.com> -- cgit v1.2.3-54-g00ecf