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Docker Remote API
Docker's Remote API uses an open schema model. In this model, unknown properties in incoming messages are ignored. Client applications need to take this behavior into account to ensure they do not break when talking to newer Docker daemons.
The API tends to be REST, but for some complex commands, like attach or pull, the HTTP connection is hijacked to transport STDOUT, STDIN, and STDERR.
By default the Docker daemon listens on unix:///var/run/docker.sock
and the
client must have root
access to interact with the daemon. If a group named
docker
exists on your system, docker
applies ownership of the socket to the
group.
The current version of the API is v1.22 which means calling /info
is the same
as calling /v1.22/info
. To call an older version of the API use
/v1.21/info
.
Use the table below to find the API version for a Docker version:
Docker version | API version | Changes |
---|---|---|
1.10.x | 1.22 | API changes |
1.9.x | 1.21 | API changes |
1.8.x | 1.20 | API changes |
1.7.x | 1.19 | API changes |
1.6.x | 1.18 | API changes |
1.5.x | 1.17 | API changes |
1.4.x | 1.16 | API changes |
1.3.x | 1.15 | API changes |
1.2.x | 1.14 | API changes |
Refer to the GitHub repository for older releases.
Authentication
Since API version 1.2, the auth configuration is now handled client side, so the
client has to send the authConfig
as a POST
in /images/(name)/push
. The
authConfig
, set as the X-Registry-Auth
header, is currently a Base64 encoded
(JSON) string with the following structure:
{"username": "string", "password": "string", "email": "string",
"serveraddress" : "string", "auth": ""}
Callers should leave the auth
empty. The serveraddress
is a domain/ip
without protocol. Throughout this structure, double quotes are required.
Using Docker Machine with the API
If you are using docker-machine
, the Docker daemon is on a virtual host that uses an encrypted TCP socket. This means, for Docker Machine users, you need to add extra parameters to curl
or wget
when making test API requests, for example:
curl --insecure --cert ~/.docker/cert.pem --key ~/.docker/key.pem https://YOUR_VM_IP:2376/images/json
wget --no-check-certificate --certificate=$DOCKER_CERT_PATH/cert.pem --private-key=$DOCKER_CERT_PATH/key.pem https://your_vm_ip:2376/images/json -O - -q
Docker Events
The following diagram depicts the container states accessible through the API.
Some container-related events are not affected by container state, so they are not included in this diagram. These events are:
- export emitted by
docker export
- exec_create emitted by
docker exec
- exec_start emitted by
docker exec
after exec_create
Running docker rmi
emits an untag event when removing an image name. The rmi
command may also emit delete events when images are deleted by ID directly or by deleting the last tag referring to the image.
Acknowledgement: This diagram and the accompanying text were used with the permission of Matt Good and Gilder Labs. See Matt's original blog post Docker Events Explained.
Version history
This section lists each version from latest to oldest. Each listing includes a link to the full documentation set and the changes relevant in that release.
v1.22 API changes
Docker Remote API v1.22 documentation
GET /containers/json
supports filterisolation
on Windows.GET /info
Now returnsArchitecture
andOSType
fields, providing information about the host architecture and operating system type that the daemon runs on.GET /networks/(name)
now returns aName
field for each container attached to the network.GET /version
now returns theBuildTime
field in RFC3339Nano format to make it consistent with other date/time values returned by the API.
v1.21 API changes
Docker Remote API v1.21 documentation
GET /volumes
lists volumes from all volume drivers.POST /volumes/create
to create a volume.GET /volumes/(name)
get low-level information about a volume.DELETE /volumes/(name)
remove a volume with the specified name.VolumeDriver
was moved fromconfig
toHostConfig
to make the configuration portable.GET /images/(name)/json
now returns information about an image'sRepoTags
andRepoDigests
.- The
config
option now accepts the fieldStopSignal
, which specifies the signal to use to kill a container. GET /containers/(id)/stats
will return networking information respectively for each interface.- The
HostConfig
option now includes theDnsOptions
field to configure the container's DNS options. POST /build
now optionally takes a serialized map of build-time variables.GET /events
now includes atimenano
field, in addition to the existingtime
field.GET /events
now supports filtering by image and container labels.GET /info
now lists engine version information and return the information ofCPUShares
andCpuset
.GET /containers/json
will returnImageID
of the image used by container.POST /exec/(name)/start
will now return an HTTP 409 when the container is either stopped or paused.GET /containers/(name)/json
now accepts asize
parameter. Setting this parameter to '1' returns container size information in theSizeRw
andSizeRootFs
fields.GET /containers/(name)/json
now returns aNetworkSettings.Networks
field, detailing network settings per network. This field deprecates theNetworkSettings.Gateway
,NetworkSettings.IPAddress
,NetworkSettings.IPPrefixLen
, andNetworkSettings.MacAddress
fields, which are still returned for backward-compatibility, but will be removed in a future version.GET /exec/(id)/json
now returns aNetworkSettings.Networks
field, detailing networksettings per network. This field deprecates theNetworkSettings.Gateway
,NetworkSettings.IPAddress
,NetworkSettings.IPPrefixLen
, andNetworkSettings.MacAddress
fields, which are still returned for backward-compatibility, but will be removed in a future version.- The
HostConfig
option now includes theOomScoreAdj
field for adjusting the badness heuristic. This heuristic selects which processes the OOM killer kills under out-of-memory conditions.
v1.20 API changes
Docker Remote API v1.20 documentation
GET /containers/(id)/archive
get an archive of filesystem content from a container.PUT /containers/(id)/archive
upload an archive of content to be extracted to an existing directory inside a container's filesystem.POST /containers/(id)/copy
is deprecated in favor of the abovearchive
endpoint which can be used to download files and directories from a container.- The
hostConfig
option now accepts the fieldGroupAdd
, which specifies a list of additional groups that the container process will run as.
v1.19 API changes
Docker Remote API v1.19 documentation
- When the daemon detects a version mismatch with the client, usually when the client is newer than the daemon, an HTTP 400 is now returned instead of a 404.
GET /containers/(id)/stats
now acceptsstream
bool to get only one set of stats and disconnect.GET /containers/(id)/logs
now accepts asince
timestamp parameter.GET /info
The fieldsDebug
,IPv4Forwarding
,MemoryLimit
, andSwapLimit
are now returned as boolean instead of as an int. In addition, the end point now returns the new boolean fieldsCpuCfsPeriod
,CpuCfsQuota
, andOomKillDisable
.- The
hostConfig
option now accepts the fieldsCpuPeriod
andCpuQuota
POST /build
acceptscpuperiod
andcpuquota
options
v1.18 API changes
Docker Remote API v1.18 documentation
GET /version
now returnsOs
,Arch
andKernelVersion
.POST /containers/create
andPOST /containers/(id)/start
allow you to set ulimit settings for use in the container.GET /info
now returnsSystemTime
,HttpProxy
,HttpsProxy
andNoProxy
.GET /images/json
added aRepoDigests
field to include image digest information.POST /build
can now set resource constraints for all containers created for the build.CgroupParent
can be passed in the host config to setup container cgroups under a specific cgroup.POST /build
closing the HTTP request cancels the buildPOST /containers/(id)/exec
includesWarnings
field to response.
v1.17 API changes
Docker Remote API v1.17 documentation
- The build supports
LABEL
command. Use this to add metadata to an image. For example you could add data describing the content of an image.LABEL "com.example.vendor"="ACME Incorporated"
POST /containers/(id)/attach
andPOST /exec/(id)/start
- The Docker client now hints potential proxies about connection hijacking using HTTP Upgrade headers.
POST /containers/create
sets labels on container create describing the container.GET /containers/json
returns the labels associated with the containers (Labels
).GET /containers/(id)/json
returns the list current execs associated with the container (ExecIDs
). This endpoint now returns the container labels (Config.Labels
).POST /containers/(id)/rename
renames a containerid
to a new name.*POST /containers/create
andPOST /containers/(id)/start
callers can passReadonlyRootfs
in the host config to mount the container's root filesystem as read only.GET /containers/(id)/stats
returns a live stream of a container's resource usage statistics.GET /images/json
returns the labels associated with each image (Labels
).
v1.16 API changes
GET /info
returns the number of CPUs available on the machine (NCPU
), total memory available (MemTotal
), a user-friendly name describing the running Docker daemon (Name
), a unique ID identifying the daemon (ID
), and a list of daemon labels (Labels
).POST /containers/create
callers can set the new container's MAC address explicitly.- Volumes are now initialized when the container is created.
POST /containers/(id)/copy
copies data which is contained in a volume.
v1.15 API changes
Docker Remote API v1.15 documentation
POST /containers/create
you can set a container's HostConfig
when creating a
container. Previously this was only available when starting a container.
v1.14 API changes
Docker Remote API v1.14 documentation
DELETE /containers/(id)
when usingforce
, the container will be immediately killed with SIGKILL.POST /containers/(id)/start
theHostConfig
option accepts the fieldCapAdd
, which specifies a list of capabilities to add, and the fieldCapDrop
, which specifies a list of capabilities to drop.POST /images/create
thfromImage
andrepo
parameters support therepo:tag
format. Consequently, thetag
parameter is now obsolete. Using the new format and thetag
parameter at the same time will return an error.