docker-registry-client

node-docker-registry-client

A Docker Registry API client for node.js.

Limitations: Currently only support for Registry API v1 (https://docs.docker.com/v1.6/reference/api/registry_api/) pull support (i.e. excluding API endpoints for push) and Registry API v2 pull support. Support for v2 push endpoints is coming.

Note: This repository is part of the Joyent Triton project. See the contribution guidelines and general documentation at the main Triton project page.

Install

npm install docker-registry-client

Overview

Most usage of this package involves creating a Registry API client for a specific repository and calling its methods.

A Registry client requires a repository name (called a repo in the code):

[INDEX/]NAME                # a "repo name"

Examples:

mongo                       # implies default index (docker.io) and namespace (library)
docker.io/mongo             # same thing
docker.io/library/mongo     # same thing

myreg.example.com:5000/busybox   # a "busybox" repo on a private registry

quay.io/trentm/foo          # trentm's "foo" repo on the quay.io service

The parseRepo function is used to parse these. See "examples/parseRepo.js" to see how they are parsed:

$ node examples/parseRepo.js mongo
{
    "index": {
        "name": "docker.io",
        "official": true
    },
    "official": true,
    "remoteName": "library/mongo",
    "localName": "mongo",
    "canonicalName": "docker.io/mongo"
}

Commonly, a "repo name and tag" string is used for working with a Docker registry, e.g. docker pull busybox:latest. The v2 API adds support for using "repo name and digest" to stably identify images, e.g. docker pull alpine@sha256:fb9f16730ac6316afa4d97caa5130219927bfcecf0b0ce35c01dcb612f449739. This package provides a parseRepoAndRef (and the synonym parseRepoAndTag) for that, e.g.:

$ node examples/parseRepoAndRef.js myreg.example.com:5000/busybox:foo
{
    "index": {
        "name": "myreg.example.com:5000",
        "official": false
    },
    "official": false,
    "remoteName": "busybox",
    "localName": "myreg.example.com:5000/busybox",
    "canonicalName": "myreg.example.com:5000/busybox",
    "tag": "foo"
}

Slightly different than docker.git's parsing, this package allows the scheme to be given on the index:

$ node examples/parseRepoAndRef.js https://quay.io/trentm/foo
{
    "index": {
        "scheme": "https",              // <--- scheme
        "name": "quay.io",
        "official": false
    },
    "official": false,
    "remoteName": "trentm/foo",
    "localName": "quay.io/trentm/foo",
    "canonicalName": "quay.io/trentm/foo",
    "tag": "latest"                     // <--- default to 'latest' tag
}

If a scheme isn't given, then "https" is assumed.

Usage

If you know, for example, that you are only dealing with a v2 Docker Registry, then simple usage will look like this:

var drc = require('docker-registry-client');
var REPO = 'alpine';
var client = drc.createClientV2({name: REPO});

client.listTags(function (err, tags) {
    // ...
    console.log(JSON.stringify(tags, null, 4));

    /*
     * Because the client is typically using Keep-Alive, it will maintain
     * open connections. Therefore you should call `.close()` to close
     * those when finished.
     */
    client.close();
});

A more complete example (showing logging, auth, etc.):

var bunyan = require('bunyan');
var drc = require('docker-registry-client');

// This package uses https://github.com/trentm/node-bunyan for logging.
var log = bunyan.createLogger({
    name: 'regplay',
    // TRACE-level logging will show you all request/response activity
    // with the registry. This isn't suggested for production usage.
    level: 'trace'
});

var REPO = 'alpine';
var client = drc.createClientV2({
    name: REPO,
    log: log,
    // Optional basic auth to the registry
    username: <username>,
    password: <password>,
    // Optional, for a registry without a signed TLS certificate.
    insecure: <true|false>,
    // ... see the source code for other options
});

This package also supports the nominal technique for pinging the registry to see if it supports v2, otherwise falling back to v1:

var drc = require('docker-registry-client');

var REPO = 'alpine';
drc.createClient({name: REPO, /* ... */}, function (err, client) {
    console.log('Got a Docker Registry API v%d client', client.version);
    // ...
});

v2 API

A mapping of the Docker Registry API v2 endpoints to the API equivalents in this client lib. "NYI" means the endpoint is not yet implemented by this client lib.

Name	Endpoint	Description
ping	GET /v2/	Check that the endpoint implements Docker Registry API V2.
listTags	GET /v2/<name>/tags/list	Fetch the tags under the repository identified by name.
getManifest	GET /v2/<name>/manifests/<reference>	Fetch the manifest identified by name and reference where reference can be a tag or digest.
putManifest	PUT /v2/<name>/manifests/<reference>	NYI. Put the manifest identified by name and reference where reference can be a tag or digest.
deleteManifest	DELETE /v2/<name>/manifests/<reference>	NYI. Delete the manifest identified by name and reference where reference can be a tag or digest.
createBlobReadStream	GET /v2/<name>/blobs/<digest>	Retrieve the blob from the registry identified by digest.
headBlob	HEAD /v2/<name>/blobs/<digest>	Retrieve the blob from the registry identified by digest -- just the headers.
startBlobUpload	POST /v2/<name>/blobs/uploads/	NYI. Initiate a resumable blob upload. If successful, an upload location will be provided to complete the upload. Optionally, if the digest parameter is present, the request body will be used to complete the upload in a single request.
getBlobUploadStatus	GET /v2/<name>/blobs/uploads/<uuid>	NYI. Retrieve status of upload identified by uuid. The primary purpose of this endpoint is to resolve the current status of a resumable upload.
uploadBlobChunk	PATCH /v2/<name>/blobs/uploads/<uuid>	NYI. Upload a chunk of data for the specified upload.
completeBlobUpload	PUT /v2/<name>/blobs/uploads/<uuid>	NYI. Complete the upload specified by uuid, optionally appending the body as the final chunk.
cancelBlobUpload	DELETE /v2/<name>/blobs/uploads/<uuid>	NYI. Cancel outstanding upload processes, releasing associated resources. If this is not called, the unfinished uploads will eventually timeout.
deleteBlob	DELETE /v2/<name>/blobs/<digest>	NYI. Delete the blob identified by name and digest. Warning: From the Docker spec I'm not sure that deleteBlob doesn't corrupt images if you delete a shared blob.
listRepositories	GET /v2/_catalog/	NYI List all repositories in this registry. Spec.

See "examples/v2/*.js" for short code examples one can run from the CLI for each API endpoint. E.g.:

$ npm install   # install dependencies for this module
$ node examples/v2/listTags.js busybox
{
    "name": "library/busybox",
    "tags": [
        "buildroot-2013.08.1",
        "buildroot-2014.02",
        "latest",
        "ubuntu-12.04",
        "ubuntu-14.04"
    ]
}

You can also get logging on processing and HTTP requests/responses via the -v option to the example scripts. This library uses Bunyan for logging, so you'll want to pipe the log output (on stderr) through the bunyan command for pretty output:

$ node examples/v2/listTags.js -v busybox 2>&1 | ./node_modules/.bin/bunyan
[2015-06-01T22:26:44.065Z] TRACE: v2.listTags/registry/23400 on grape.local: request sent
    GET /v2/ HTTP/1.1
    Host: registry-1.docker.io
    accept: application/json
    user-agent: node-docker-registry-client/2.0.0 (x64-darwin; node/0.10.28)
    date: Mon, 01 Jun 2015 22:26:44 GMT
[2015-06-01T22:26:44.480Z] TRACE: v2.listTags/registry/23400 on grape.local: Response received (client_res={})
    HTTP/1.1 401 Unauthorized
    content-type: application/json; charset=utf-8
    docker-distribution-api-version: registry/2.0
    www-authenticate: Bearer realm="https://auth.docker.io/token",service="registry.docker.io"
    date: Mon, 01 Jun 2015 22:26:44 GMT
    content-length: 114
    connection: close
    strict-transport-security: max-age=3153600
[2015-06-01T22:26:44.482Z] TRACE: v2.listTags/registry/23400 on grape.local:
    body received:
    {"errors":[{"code":"UNAUTHORIZED","message":"access to the requested resource is not authorized","detail":null}]}
[2015-06-01T22:26:44.485Z] TRACE: v2.listTags/registry/23400 on grape.local: login
[2015-06-01T22:26:44.487Z] DEBUG: v2.listTags/registry/23400 on grape.local: login: get Bearer auth token
...
[2015-06-01T22:26:45.680Z] TRACE: v2.listTags/registry/23400 on grape.local:
    body received:
    {"name":"library/busybox","tags":["buildroot-2013.08.1","buildroot-2014.02","latest","ubuntu-12.04","ubuntu-14.04"]}
{
    "name": "library/busybox",
    "tags": [
        "buildroot-2013.08.1",
        "buildroot-2014.02",
        "latest",
        "ubuntu-12.04",
        "ubuntu-14.04"
    ]
}

v1 API

A mapping of the Docker Registry API v1 endpoints to the API equivalents in this client lib.

Limitation: Only the read endpoints of the v1 API are implement. I.e. putting layers, deleting repositories, setting/deleting tags are all not implemented.

Name	Endpoint	Description
ping	GET /v1/_ping	Check status of the registry.
search	GET /v1/search	Search the index.
listRepoImgs	GET /v1/repositories/$repo/images	List all images in this repo. This is actually against the "Index API" (aka "Hub API").
listRepoTags	GET /v1/repositories/$repo/tags	List all tags for a repo.
getImgAncestry	GET /v1/images/$imgId/ancestry	Get the ancestry of an image.
getImgJson	GET /v1/images/$imgId/json	Get the metadata (sometimes called the "image JSON") for an image.
getImgLayerStream	GET /v1/images/$imgId/layer	Download the image layer file.
-	PUT /v1/images/$imgId/layer	Not implemented. Put image layer.
-	DELETE /v1/repositories/$repo/tags/$tag	Not implemented. Delete a repo tag.
-	PUT /v1/repositories/$repo/tags/$tag	Not implemented. Set a repo tag.
-	DELETE /v1/repositories/$repo	Not implemented. Delete a repo.

See "examples/v1/*.js" for short code examples one can run from the CLI for each API endpoint. E.g.:

$ npm install   # install dependencies for this module
$ node examples/v1/listRepoTags.js busybox
{
    "buildroot-2013.08.1": "3dba22db9896eb5f020691e1f8cda46735de533ca7b6b1b3b072272752935bad",
    "buildroot-2014.02": "8c2e06607696bd4afb3d03b687e361cc43cf8ec1a4a725bc96e39f05ba97dd55",
    "latest": "8c2e06607696bd4afb3d03b687e361cc43cf8ec1a4a725bc96e39f05ba97dd55",
    "ubuntu-12.04": "faf804f0e07b2936e84c9fe4ca7c60a6246cc669cf2ff70969f14a9eab6efb48",
    "ubuntu-14.04": "32e97f5f5d6bd15b9cc293b38a5102a7ddac736852811110043992b20553177a"
}

You can also get logging on processing and HTTP requests/responses via the -v option to the example scripts. This library uses Bunyan for logging, so you'll want to pipe the log output (on stderr) through the bunyan command for pretty output:

$ node listRepoTags.js -v busybox 2>&1 | bunyan
[2015-09-02T22:14:35.790Z] TRACE: listRepoTags/registry/13388 on danger0.local: get session token/cookie
[2015-09-02T22:14:35.836Z] TRACE: listRepoTags/registry/13388 on danger0.local: request sent
    GET /v1/repositories/library/busybox/images HTTP/1.1
    Host: index.docker.io
    X-Docker-Token: true
    accept: application/json
    user-agent: node-docker-registry-client/2.0.0 (x64-darwin; node/0.10.40)
    date: Wed, 02 Sep 2015 22:14:35 GMT
[2015-09-02T22:14:36.374Z] TRACE: listRepoTags/registry/13388 on danger0.local: Response received (client_res={})
    HTTP/1.1 200 OK
    server: nginx/1.6.2
    date: Wed, 02 Sep 2015 22:14:36 GMT
...
[2015-09-02T22:14:37.888Z] TRACE: listRepoTags/registry/13388 on danger0.local:
    body received:
    {"buildroot-2013.08.1": "3dba22db9...
[2015-09-02T22:14:37.888Z] TRACE: listRepoTags/registry/13388 on danger0.local: close http client (host=index.docker.io)
[2015-09-02T22:14:37.889Z] TRACE: listRepoTags/registry/13388 on danger0.local: close http client (host=registry-1.docker.io)
{
    "buildroot-2013.08.1": "3dba22db9896eb5f020691e1f8cda46735de533ca7b6b1b3b072272752935bad",
    "buildroot-2014.02": "8c2e06607696bd4afb3d03b687e361cc43cf8ec1a4a725bc96e39f05ba97dd55",
    "latest": "8c2e06607696bd4afb3d03b687e361cc43cf8ec1a4a725bc96e39f05ba97dd55",
    "ubuntu-12.04": "faf804f0e07b2936e84c9fe4ca7c60a6246cc669cf2ff70969f14a9eab6efb48",
    "ubuntu-14.04": "32e97f5f5d6bd15b9cc293b38a5102a7ddac736852811110043992b20553177a"
}

V1 client usage:

var repo = 'alpine';
var client = drc.createClientV1({
    name: repo,
    // ...
});
client.listRepoTags(function (err, repoTags) {
    client.close();
    if (err) {
        console.log(err);
        process.exit(1);
    }
    console.log(JSON.stringify(repoTags, null, 4));
});

Development

Naming convensions

For naming this package attempts to consistently use repo for repository, img for image, etc.

Commits

Before commit, ensure that the following checks are clean:

make prepush

Releases

Changes with possible user impact should:

• Add a note to the changelog (CHANGES.md).

• Bump the package version appropriately.

• Once merged to master, the new version should be tagged and published to npm via:

   make cutarelease
  

  To list to npm accounts that have publish access:

   npm owner ls docker-registry-client
  

The desire is that users of this package use published versions in their package.json dependencies, rather than depending on git shas.