This PR adds support for user-defined health-check probes for Docker
containers. It adds a `HEALTHCHECK` instruction to the Dockerfile syntax plus
some corresponding "docker run" options. It can be used with a restart policy
to automatically restart a container if the check fails.
The `HEALTHCHECK` instruction has two forms:
* `HEALTHCHECK [OPTIONS] CMD command` (check container health by running a command inside the container)
* `HEALTHCHECK NONE` (disable any healthcheck inherited from the base image)
The `HEALTHCHECK` instruction tells Docker how to test a container to check that
it is still working. This can detect cases such as a web server that is stuck in
an infinite loop and unable to handle new connections, even though the server
process is still running.
When a container has a healthcheck specified, it has a _health status_ in
addition to its normal status. This status is initially `starting`. Whenever a
health check passes, it becomes `healthy` (whatever state it was previously in).
After a certain number of consecutive failures, it becomes `unhealthy`.
The options that can appear before `CMD` are:
* `--interval=DURATION` (default: `30s`)
* `--timeout=DURATION` (default: `30s`)
* `--retries=N` (default: `1`)
The health check will first run **interval** seconds after the container is
started, and then again **interval** seconds after each previous check completes.
If a single run of the check takes longer than **timeout** seconds then the check
is considered to have failed.
It takes **retries** consecutive failures of the health check for the container
to be considered `unhealthy`.
There can only be one `HEALTHCHECK` instruction in a Dockerfile. If you list
more than one then only the last `HEALTHCHECK` will take effect.
The command after the `CMD` keyword can be either a shell command (e.g. `HEALTHCHECK
CMD /bin/check-running`) or an _exec_ array (as with other Dockerfile commands;
see e.g. `ENTRYPOINT` for details).
The command's exit status indicates the health status of the container.
The possible values are:
- 0: success - the container is healthy and ready for use
- 1: unhealthy - the container is not working correctly
- 2: starting - the container is not ready for use yet, but is working correctly
If the probe returns 2 ("starting") when the container has already moved out of the
"starting" state then it is treated as "unhealthy" instead.
For example, to check every five minutes or so that a web-server is able to
serve the site's main page within three seconds:
HEALTHCHECK --interval=5m --timeout=3s \
CMD curl -f http://localhost/ || exit 1
To help debug failing probes, any output text (UTF-8 encoded) that the command writes
on stdout or stderr will be stored in the health status and can be queried with
`docker inspect`. Such output should be kept short (only the first 4096 bytes
are stored currently).
When the health status of a container changes, a `health_status` event is
generated with the new status. The health status is also displayed in the
`docker ps` output.
Signed-off-by: Thomas Leonard <thomas.leonard@docker.com>
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
The -f flag on docker tag has been deprecated in docker 1.10 and
is expected to be removed in docker 1.12.
This fix removed the -f flag on docker tag and also updated
deprecated.md.
NOTE: A separate pull request for engine-api has been opened to
cover the related changes.
Signed-off-by: Yong Tang <yong.tang.github@outlook.com>
The Seccomp tests ran 11 tests in parallel and this appears to be
hitting some sort of bug on CI. Splitting into two tests means that
I can no longer repeoduce the failure on the slow laptop where I could
reproduce the failures before.
Obviously this does not fix the underlying issue, which I will
continue to investigate, but not having the tests failing a lot
before the freeze for 1.12 would be rather helpful.
Signed-off-by: Justin Cormack <justin.cormack@docker.com>
This fix tries to address the issue raised in #22420. When
`--tmpfs` is specified with `/tmp`, the default value is
`rw,nosuid,nodev,noexec,relatime,size=65536k`. When `--tmpfs`
is specified with `/tmp:rw`, then the value changed to
`rw,nosuid,nodev,noexec,relatime`.
The reason for such an inconsistency is because docker tries
to add `size=65536k` option only when user provides no option.
This fix tries to address this issue by always pre-progating
`size=65536k` along with `rw,nosuid,nodev,noexec,relatime`.
If user provides a different value (e.g., `size=8192k`), it
will override the `size=65536k` anyway since the combined
options will be parsed and merged to remove any duplicates.
Additional test cases have been added to cover the changes
in this fix.
This fix fixes#22420.
Signed-off-by: Yong Tang <yong.tang.github@outlook.com>
Updating `integration-cli/daemon.go` to use `dockerd` instead of `docker
daemon` to start up the daemon.
Signed-off-by: Vincent Demeester <vincent@sbr.pm>
Add support for two now filter on the `images` command : `before` and
`since`. They work the same as the one on the `ps` command but for
images.
$ docker images --filter before=myimage
# display all images older than myimage
$ docker images --filter since=myimage
# display all images younger than myimage
Signed-off-by: Vincent Demeester <vincent@sbr.pm>
This fix tries to address the issue raised in #21976 and allows
the options of `--add-host` and `--net=host` to work at the same time.
The documentation has been updated and additional tests have been
added to cover this change.
This fix fixes#21976.
Signed-off-by: Yong Tang <yong.tang.github@outlook.com>
The generated profile that we check in is for amd64 and i386 architectures
and does not work correctly on arm as it is missing required syscalls,
and also specifies the architectures that are supported. It works on
ppc64le at the moment but better to skip the test as it is likely to
break in future.
Signed-off-by: Justin Cormack <justin.cormack@docker.com>
This fix tries to address the issue raised in #21976 and allows
the options of `--dns`, `--dns-search`, `--dns-opt` and `--net=host`
to work at the same time.
The documentation has been updated and additional tests have been
added to cover this change.
This fix fixes#21976.
Signed-off-by: Yong Tang <yong.tang.github@outlook.com>
Fixes the test by loading in the architecture specific busybox
image when the test daemon starts.
Signed-off-by: Christopher Jones <tophj@linux.vnet.ibm.com>
Currently, using a custom detach key with an invalid sequence, eats a
part of the sequence, making it weird and difficult to enter some key
sequence.
This fixes by keeping the input read when trying to see if it's the key
sequence or not, and "writing" then is the key sequence is not the right
one, preserving the initial input.
Signed-off-by: Vincent Demeester <vincent@sbr.pm>
This fix tries to cover the issue raised in #22463 by adding
filter for events emitted by docker daemon so that user could
utilize filter to receive events of interest.
Documentations have been updated for this fix.
Additional tests have been added to cover the changes in this fix.
This fix fixes#22463.
Signed-off-by: Yong Tang <yong.tang.github@outlook.com>
This fix tries to cover the issue raised in #22463 by emitting
events for docker daemon so that user could be notified by
scenarios like config reload, etc.
This fix adds the `daemon reload`, and events for docker daemon.
Additional tests have been added to cover the changes in this fix.
This fix fixes#22463.
Signed-off-by: Yong Tang <yong.tang.github@outlook.com>
It appears that on some systems apparmor gets in the way of libc.so.6
shared library being loaded - which means the ping fails.
To get around this if we run ping under `/lib64/ld-linux-x86-64.so.2`
then it works. So we only do this for linux and only if the first attempt
fails. If this 2nd attempt fails then we'll show the original error to
the user for debugging.
Also s/Output/CombinedOutput/ to help debugging in the future. It didn't
show the real error msg.
Signed-off-by: Doug Davis <dug@us.ibm.com>
This was not changed when the additional tests were added.
It may be the reason for occasional test failures.
Signed-off-by: Justin Cormack <justin.cormack@docker.com>
This test is not applicable anymore now that containers are not stopped
when the daemon is restored.
Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
For me when I run the test I see:
```
Downloading from http://nourl/bad
Importing 283 B
Untar re-exec error: exit status 1: output: unexpected EOF
```
and nothing about "dial tcp" so it appears that the output is
system dependent and therefore we can't really check it. I think
checking for non-zero exit code is sufficient so I'm removing this
string check.
Signed-off-by: Doug Davis <dug@us.ibm.com>
