moby--moby/cmd/dockerd
Sebastiaan van Stijn 51c7992928
API: add "prune" events
This patch adds a new "prune" event type to indicate that pruning of a resource
type completed.

This event-type can be used on systems that want to perform actions after
resources have been cleaned up. For example, Docker Desktop performs an fstrim
after resources are deleted (https://github.com/linuxkit/linuxkit/tree/v0.7/pkg/trim-after-delete).

While the current (remove, destroy) events can provide information on _most_
resources, there is currently no event triggered after the BuildKit build-cache
is cleaned.

Prune events have a `reclaimed` attribute, indicating the amount of space that
was reclaimed (in bytes). The attribute can be used, for example, to use as a
threshold for performing fstrim actions. Reclaimed space for `network` events
will always be 0, but the field is added to be consistent with prune events for
other resources.

To test this patch:

Create some resources:

    for i in foo bar baz; do \
        docker network create network_$i \
        && docker volume create volume_$i \
        && docker run -d --name container_$i -v volume_$i:/volume busybox sh -c 'truncate -s 5M somefile; truncate -s 5M /volume/file' \
        && docker tag busybox:latest image_$i; \
    done;

    docker pull alpine
    docker pull nginx:alpine

    echo -e "FROM busybox\nRUN truncate -s 50M bigfile" | DOCKER_BUILDKIT=1 docker build -

Start listening for "prune" events in another shell:

    docker events --filter event=prune

Prune containers, networks, volumes, and build-cache:

    docker system prune -af --volumes

See the events that are returned:

    docker events --filter event=prune
    2020-07-25T12:12:09.268491000Z container prune  (reclaimed=15728640)
    2020-07-25T12:12:09.447890400Z network prune  (reclaimed=0)
    2020-07-25T12:12:09.452323000Z volume prune  (reclaimed=15728640)
    2020-07-25T12:12:09.517236200Z image prune  (reclaimed=21568540)
    2020-07-25T12:12:09.566662600Z builder prune  (reclaimed=52428841)

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
2020-07-28 12:41:14 +02:00
..
README.md Fix readme doc for dockerd 2016-09-01 14:47:51 +08:00
config.go fix --cluster-store-opt deprecation annotation 2020-04-16 14:42:19 +02:00
config_common_unix.go dockerd: fix rootless detection (alternative to #39024) 2019-04-25 16:47:01 +09:00
config_unix.go cmd/dockerd: remove outdated "experimental" annotation 2020-04-29 11:06:11 +09:00
config_unix_test.go bump gotest.tools v3.0.1 for compatibility with Go 1.14 2020-02-11 00:06:42 +01:00
config_windows.go allow running `dockerd` in an unprivileged user namespace (rootless mode) 2019-02-04 00:24:27 +09:00
daemon.go API: add "prune" events 2020-07-28 12:41:14 +02:00
daemon_freebsd.go Windows: Wait for OOBE to prevent crashing during host update 2017-02-15 14:01:54 -08:00
daemon_linux.go vendor containerd, BuildKit, protobuf, grpc, and golang.org/x 2020-03-03 10:25:20 +09:00
daemon_test.go bump gotest.tools v3.0.1 for compatibility with Go 1.14 2020-02-11 00:06:42 +01:00
daemon_unix.go Remove hack MalformedHostHeaderOverride 2019-07-18 21:25:04 +02:00
daemon_unix_test.go bump gotest.tools v3.0.1 for compatibility with Go 1.14 2020-02-11 00:06:42 +01:00
daemon_windows.go Remove hack MalformedHostHeaderOverride 2019-07-18 21:25:04 +02:00
docker.go vendor: spf13/cobra v1.0.0 2020-05-08 10:44:36 +02:00
docker_unix.go Windows:Add ETW logging hook 2019-03-12 18:41:55 -07:00
docker_windows.go Windows:Add ETW logging hook 2019-03-12 18:41:55 -07:00
metrics.go Do not require "experimental" for metrics API 2020-04-20 22:19:00 +02:00
options.go allow running `dockerd` in an unprivileged user namespace (rootless mode) 2019-02-04 00:24:27 +09:00
options_test.go bump gotest.tools v3.0.1 for compatibility with Go 1.14 2020-02-11 00:06:42 +01:00
service_unsupported.go Split daemon service code to _windows file 2018-03-21 12:57:53 +01:00
service_windows.go Use hcsshim osversion package for Windows versions 2019-10-22 02:53:00 +02:00

README.md

docker.go contains Docker daemon's main function.

This file provides first line CLI argument parsing and environment variable setting.