erldocker

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erldocker

erldocker is an Erlang application that implements Docker Remote API v1.4.

Public modules are: docker, docker_container and docker_image.

Setting up

To get started, add erldocker app to your release applications list. If you don't use releases, check out the Makefile.

Configuration

Check out run/sys.config. By default, docker listens on a unix socket serving HTTP. Since Erlang releases before OTP 19.0 don't have anything like gen_unix out of the box, I'm using erldocker_unixbridge that spawns socat to bridge AF_UNIX to AF_INET.

    {erldocker, [
            {unixbridge_port, 32133},
            {docker_http, <<"http://localhost:32133">>}
    ]}

In newer versions you can set the scheme to http+unix:

    {erldocker, [
            {docker_http, <<"http+unix://%2Fvar%2Frun%2Fdocker.sock">>}
    ]}

If your docker is configured to listen on a TCP port, you may use the following configuration:

    {erldocker, [
            {docker_http, <<"http://localhost:4243">>}
    ]}

Erlang APIs

The APIs are pretty straightforward in general. Please note that the library is under heavy development and some of the APIs (namely the ones that use POST bodies) are not very nice as of right now. This will change without further notice.

Check out the examples:

> docker_container:containers().
{ok,[[{'Id',<<"6274938616c28e82b49b3ab120f9e9b9d96592d3b5bb95b53e91f740aca76243">>},
      {'Image',<<"base:latest">>},
      {'Command',<<"/bin/bash -c while true; do sleep 1; date; done">>},
      {'Created',1378278965},
      {'Status',<<"Up About an hour">>},
      {'Ports',<<>>},
      {'SizeRw',0},
      {'SizeRootFs',0}],
     [{'Id',<<"a574cdc01fa64e9b7e359d8d76f734505a4d9d121e39af877fab8c14a5d93baf">>},
      {'Image',<<"base:latest">>},
      {'Command',<<"/bin/bash -c while true; do sleep 1; date; done">>},
      {'Created',1378278960},
      {'Status',<<"Up About an hour">>},
      {'Ports',<<>>},
      {'SizeRw',0},
      {'SizeRootFs',0}]]}

> docker_container:attach_stream("687264242").
{ok,<0.167.0>}

> flush().
Shell got {<0.167.0>,{data,<<"Wed Sep  4 08:52:18 UTC 2013\n">>}}
Shell got {<0.167.0>,{data,<<"Wed Sep  4 08:52:19 UTC 2013\n">>}}
Shell got {<0.167.0>,{data,<<"Wed Sep  4 08:52:20 UTC 2013\n">>}}
ok

> exit(pid(0,167,0), kill).
** exception exit: killed

> docker_container:kill("687264242").
{ok,{204,<<>>}}

> {ok, Info} = docker_container:container("687264242"),
  {_, Image} = lists:keyfind('Image', 1, Info).
{'Image',<<"b750fe79269d2ec9a3c593ef05b4332b1d1a02a62b4accb2c21d589ff2f5f2dc">>}

> docker_image:image(Image).
{ok,[{id,<<"b750fe79269d2ec9a3c593ef05b4332b1d1a02a62b4accb2c21d589ff2f5f2dc">>},
     {parent,<<"27cf784147099545">>},
     {created,<<"2013-03-23T22:24:18.818426-07:00">>},
     {container,<<"3d67245a8d72ecf13f33dffac9f79dcdf70f75acb84d308770391510e0c23ad0">>},
     {container_config,[{'Hostname',<<>>},
                        {'User',<<>>},
                        {'Memory',0},
                        {'MemorySwap',0},
                        {'CpuShares',0},
                        {'AttachStdin',false},
                        {'AttachStdout',false},
                        {'AttachStderr',false},
                        {'PortSpecs',null},
                        {'Tty',true},
                        {'OpenStdin',true},
                        {'StdinOnce',false},
                        {'Env',null},
                        {'Cmd',[<<"/bin/bash">>]},
                        {'Dns',null},
                        {'Image',<<"base">>},
                        {'Volumes',null},
                        {'VolumesFrom',<<>>},
                        {'WorkingDir',...},
                        {...}|...]},
     {'Size',24653}]}