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>
These fields are needed to specify the exact version of Windows that an
image can run on. They may be useful for other platforms in the future.
This also changes image.store.Create to validate that the loaded image is
supported on the current machine. This change affects Linux as well, since
it now validates the architecture and OS fields.
Signed-off-by: John Starks <jostarks@microsoft.com>
Instead of implementing refcounts at each graphdriver, implement this in
the layer package which is what the engine actually interacts with now.
This means interacting directly with the graphdriver is no longer
explicitly safe with regard to Get/Put calls being refcounted.
In addition, with the containerd, layers may still be mounted after
a daemon restart since we will no longer explicitly kill containers when
we shutdown or startup engine.
Because of this ref counts would need to be repopulated.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
Instead of implementing refcounts at each graphdriver, implement this in
the layer package which is what the engine actually interacts with now.
This means interacting directly with the graphdriver is no longer
explicitly safe with regard to Get/Put calls being refcounted.
In addition, with the containerd, layers may still be mounted after
a daemon restart since we will no longer explicitly kill containers when
we shutdown or startup engine.
Because of this ref counts would need to be repopulated.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
Merge was used by builder and daemon. With this commit, the builder
call has been inlined and the function moved to the daemon package,
which is the only other caller.
Signed-off-by: Anusha Ragunathan <anusha@docker.com>
RWLayer will now have more operations and be protected through a referenced type rather than always looked up by string in the layer store.
Separates creation of RWLayer (write capture layer) from mounting of the layer.
This allows mount labels to be applied after creation and allowing RWLayer objects to have the same lifespan as a container without performance regressions from requiring mount.
Signed-off-by: Derek McGowan <derek@mcgstyle.net> (github: dmcgowan)
So other packages don't need to import the daemon package when they
want to use this struct.
Signed-off-by: David Calavera <david.calavera@gmail.com>
Signed-off-by: Tibor Vass <tibor@docker.com>
Closes#9798
@maintainers please note that this is a change to the UX. We no longer
require the -f flag on `docker tag` to move a tag from an existing image.
However, this does make us more consistent across our commands,
see https://github.com/docker/docker/issues/9798 for the history.
Signed-off-by: Doug Davis <dug@us.ibm.com>
Currently, the resources associated with the io.Reader returned by
TarStream are only freed when it is read until EOF. This means that
partial uploads or exports (for example, in the case of a full disk or
severed connection) can leak a goroutine and open file. This commit
changes TarStream to return an io.ReadCloser. Resources are freed when
Close is called.
Signed-off-by: Aaron Lehmann <aaron.lehmann@docker.com>
Add distribution package for managing pulls and pushes. This is based on
the old code in the graph package, with major changes to work with the
new image/layer model.
Add v1 migration code.
Update registry, api/*, and daemon packages to use the reference
package's types where applicable.
Update daemon package to use image/layer/tag stores instead of the graph
package
Signed-off-by: Aaron Lehmann <aaron.lehmann@docker.com>
Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>
Although having a request ID available throughout the codebase is very
valuable, the impact of requiring a Context as an argument to every
function in the codepath of an API request, is too significant and was
not properly understood at the time of the review.
Furthermore, mixing API-layer code with non-API-layer code makes the
latter usable only by API-layer code (one that has a notion of Context).
This reverts commit de41640435, reversing
changes made to 7daeecd42d.
Signed-off-by: Tibor Vass <tibor@docker.com>
Conflicts:
api/server/container.go
builder/internals.go
daemon/container_unix.go
daemon/create.go
This PR adds a "request ID" to each event generated, the 'docker events'
stream now looks like this:
```
2015-09-10T15:02:50.000000000-07:00 [reqid: c01e3534ddca] de7c5d4ca927253cf4e978ee9c4545161e406e9b5a14617efb52c658b249174a: (from ubuntu) create
```
Note the `[reqID: c01e3534ddca]` part, that's new.
Each HTTP request will generate its own unique ID. So, if you do a
`docker build` you'll see a series of events all with the same reqID.
This allow for log processing tools to determine which events are all related
to the same http request.
I didn't propigate the context to all possible funcs in the daemon,
I decided to just do the ones that needed it in order to get the reqID
into the events. I'd like to have people review this direction first, and
if we're ok with it then I'll make sure we're consistent about when
we pass around the context - IOW, make sure that all funcs at the same level
have a context passed in even if they don't call the log funcs - this will
ensure we're consistent w/o passing it around for all calls unnecessarily.
ping @icecrime @calavera @crosbymichael
Signed-off-by: Doug Davis <dug@us.ibm.com>
- some method names were changed to have a 'Locking' suffix, as the
downcased versions already existed, and the existing functions simply
had locks around the already downcased version.
- deleting unused functions
- package comment
- magic numbers replaced by golang constants
- comments all over
Signed-off-by: Morgan Bauer <mbauer@us.ibm.com>
Move some calls to container.LogEvent down lower so that there's
less of a chance of them being missed. Also add a few more events
that appear to have been missed.
Added testcases for new events: commit, copy, resize, attach, rename, top
Signed-off-by: Doug Davis <dug@us.ibm.com>
daemon.Diff already implements mounting for naivegraphdriver and
aufs which does diffing on its owns does not need the container to be mounted.
So new filesystem driver should mount filesystems on their own if it is needed
to implement Diff(). This issue was reported by @kvasdopil while working on a
freebsd port, because freebsd does not allow mount an already mounted
filesystem. Also it saves some cycles for other operating systems as well.
Signed-off-by: Jörg Thalheim <joerg@higgsboson.tk>
In addition to config env, `commit` now will also accepts a `changes` env which
is a string contains new-line separated Dockerfile instructions.
`commit` will evaluate `changes` into `runconfig.Config` and merge it with
`config` env, and then finally commit a new image with the changed config
Docker-DCO-1.1-Signed-off-by: Daniel, Dao Quang Minh <dqminh89@gmail.com> (github: dqminh)
Docker-DCO-1.1-Signed-off-by: Daniel, Dao Quang Minh <dqminh89@gmail.com> (github: rhatdan)
There has been a lot of discussion (issues 4242 and 5262) about making
`FROM scratch` either a special case or making `FROM` optional, implying
starting from an empty file system.
This patch makes the build command `FROM scratch` special cased from now on
and if used does not pull/set the the initial layer of the build to the ancient
image ID (511136ea..) but instead marks the build as having no base image. The
next command in the dockerfile will create an image with a parent image ID of "".
This means every image ever can now use one fewer layer!
This also makes the image name `scratch` a reserved name by the TagStore. You
will not be able to tag an image with this name from now on. If any users
currently have an image tagged as `scratch`, they will still be able to use that
image, but will not be able to tag a new image with that name.
Goodbye '511136ea3c5a64f264b78b5433614aec563103b4d4702f3ba7d4d2698e22c158',
it was nice knowing you.
Fixes#4242
Docker-DCO-1.1-Signed-off-by: Josh Hawn <josh.hawn@docker.com> (github: jlhawn)
This is part of an effort to break apart the deprecated server/ package
Docker-DCO-1.1-Signed-off-by: Solomon Hykes <solomon@docker.com> (github: shykes)
Michael Crosby
John Howard
Thomas Leonard
David Calavera
John Starks
Brian Goff
Tonis Tiigi
Qiang Huang
Vincent Demeester
Anusha Ragunathan
Derek McGowan
Morgan Bauer
Doug Davis
Aaron Lehmann
Alexander Morozov
Tibor Vass
Ma Shimiao
Antonio Murdaca
Jessie Frazelle
Jörg Thalheim
Simei He
Antonio Murdaca
Tibor Vass
Daniel, Dao Quang Minh
Lei Jitang
Andrew C. Bodine
Josh Hawn
Solomon Hykes