distribution/docs/configuration.md

Registry Configuration Reference

You configure a registry server using a YAML file. This page explains the configuration options and the values they can take. You'll also find examples of middleware and development environment configurations.

List of configuration options

This section lists all the registry configuration options. Some options in the list are mutually exclusive. So, make sure to read the detailed reference information about each option that appears later in this page.

version: 0.1
log:
	level: debug
	formatter: text
	fields:
		service: registry
		environment: staging
	hooks:
		- type: mail
		  disabled: true
		  levels:
			- panic
		  options:
			smtp:
				addr: mail.example.com:25
				username: mailuser
				password: password
				insecure: true
			from: sender@example.com
			to: 
				- errors@example.com
loglevel: debug # deprecated: use "log"
storage:
	filesystem:
		rootdirectory: /tmp/registry
	azure:
		accountname: accountname
		accountkey: base64encodedaccountkey
		container: containername
	s3:
		accesskey: awsaccesskey
		secretkey: awssecretkey
		region: us-west-1
		bucket: bucketname
		encrypt: true
		secure: true
		v4auth: true
		chunksize: 5242880
		rootdirectory: /s3/object/name/prefix
	cache:
		blobdescriptor: redis
	maintenance:
		uploadpurging:
			enabled: true
			age: 168h
			interval: 24h
			dryrun: false
auth:
	silly:
		realm: silly-realm
		service: silly-service
	token:
		realm: token-realm
		service: token-service
		issuer: registry-token-issuer
		rootcertbundle: /root/certs/bundle
middleware:
	registry:
		- name: ARegistryMiddleware
		  options:
			foo: bar
	repository:
		- name: ARepositoryMiddleware
		  options:
			foo: bar
	storage:
		- name: cloudfront
		  options:
			baseurl: https://my.cloudfronted.domain.com/
			privatekey: /path/to/pem
			keypairid: cloudfrontkeypairid
			duration: 3000
reporting:
	bugsnag:
		apikey: bugsnagapikey
		releasestage: bugsnagreleasestage
		endpoint: bugsnagendpoint
	newrelic:
		licensekey: newreliclicensekey
		name: newrelicname
		verbose: true
http:
	addr: localhost:5000
	prefix: /my/nested/registry/
	secret: asecretforlocaldevelopment
	tls:
		certificate: /path/to/x509/public
		key: /path/to/x509/private
    clientcas:
      - /path/to/ca.pem
      - /path/to/another/ca.pem
	debug:
		addr: localhost:5001
notifications:
	endpoints:
		- name: alistener
		  disabled: false
		  url: https://my.listener.com/event
		  headers: <http.Header>
		  timeout: 500
		  threshold: 5
		  backoff: 1000
redis:
	addr: localhost:6379
	password: asecret
	db: 0
	dialtimeout: 10ms
	readtimeout: 10ms
	writetimeout: 10ms
	pool:
		maxidle: 16
		maxactive: 64
		idletimeout: 300s

In some instances a configuration option is optional but it contains child options marked as required. This indicates that you can omit the parent with all its children. However, if the parent is included, you must also include all the children marked required.

Override configuration options

You can use environment variables to override most configuration parameters. The exception is the version variable which cannot be overridden. You can set environment variables on the command line using the -e flag on docker run or from within a Dockerfile using the ENV instruction.

To override a configuration option, create an environment variable named REGISTRY\variable_ where variable is the name of the configuration option and the _ (underscore) represents indention levels. For example, you can configure the rootdirectory of the filesystem storage backend:

storage:
	filesystem:
		rootdirectory: /tmp/registry

To override this value, set an environment variable like this:

REGISTRY_STORAGE_FILESYSTEM_ROOTDIRECTORY=/tmp/registry/test

This variable overrides the /tmp/registry value to the /tmp/registry/test directory.

Note

: If an environment variable changes a map value into a string, such as replacing the storage driver type with REGISTRY_STORAGE=filesystem, then all sub-fields will be erased. As such, specifying the storage type in the environment will remove all parameters related to the old storage configuration.

version

version: 0.1

The version option is required. It specifies the configuration's version. It is expected to remain a top-level field, to allow for a consistent version check before parsing the remainder of the configuration file.

log

The log subsection configures the behavior of the logging system. The logging system outputs everything to stdout. You can adjust the granularity and format with this configuration section.

log:
	level: debug
	formatter: text
	fields:
		service: registry
		environment: staging

Parameter	Required	Description
level	no	Sets the sensitivity of logging output. Permitted values are error, warn, info and debug. The default is info.
formatter	no	This selects the format of logging output. The format primarily affects how keyed attributes for a log line are encoded. Options are text, json or logstash. The default is text.
fields	no	A map of field names to values. These are added to every log line for the context. This is useful for identifying log messages source after being mixed in other systems.

hooks

hooks:
  - type: mail
    levels:
      - panic
    options:
      smtp:
        addr: smtp.sendhost.com:25
        username: sendername
        password: password
        insecure: true
      from: name@sendhost.com
      to:
        - name@receivehost.com

The hooks subsection configures the logging hooks' behavior. This subsection includes a sequence handler which you can use for sending mail, for example. Refer to loglevel to configure the level of messages printed.

loglevel

DEPRECATED: Please use log instead.

loglevel: debug

Permitted values are error, warn, info and debug. The default is info.

storage

storage:
	filesystem:
		rootdirectory: /tmp/registry
	azure:
		accountname: accountname
		accountkey: base64encodedaccountkey
		container: containername
	s3:
		accesskey: awsaccesskey
		secretkey: awssecretkey
		region: us-west-1
		bucket: bucketname
		encrypt: true
		secure: true
		v4auth: true
		chunksize: 5242880
		rootdirectory: /s3/object/name/prefix
	cache:
		blobdescriptor: inmemory
	maintenance:
		uploadpurging:
			enabled: true
			age: 168h
			interval: 24h
			dryrun: false

The storage option is required and defines which storage backend is in use. You must configure one backend; if you configure more, the registry returns an error.

If you are deploying a registry on Windows, be aware that a Windows volume mounted from the host is not recommended. Instead, you can use a S3, or Azure, backing data-store. If you do use a Windows volume, you must ensure that the PATH to the mount point is within Window's MAX_PATH limits. Failure to do so can result in the following error message:

mkdir /XXX protocol error and your registry will not function properly.

cache

Use the cache subsection to enable caching of data accessed in the storage backend. Currently, the only available cache provides fast access to layer metadata. This, if configured, uses the blobdescriptor field.

You can set blobdescriptor field to redis or inmemory. The redis value uses a Redis pool to cache layer metadata. The inmemory value uses an in memory map.

NOTE: Formerly, blobdescriptor was known as layerinfo. While these are equivalent, layerinfo has been deprecated, in favor or blobdescriptor.

filesystem

The filesystem storage backend uses the local disk to store registry files. It is ideal for development and may be appropriate for some small-scale production applications.

This backend has a single, required rootdirectory parameter. The parameter specifies the absolute path to a directory. The registry stores all its data here so make sure there is adequate space available.

azure

This storage backend uses Microsoft's Azure Storage platform.

Parameter	Required	Description
accountname	yes	Azure account name.
accountkey	yes	Azure account key.
container	yes	Name of the Azure container into which to store data.

S3

This storage backend uses Amazon's Simple Storage Service (S3).

Parameter	Required	Description
accesskey	yes	Your AWS Access Key.
secretkey	yes	Your AWS Secret Key.
region	yes	The AWS region in which your bucket exists. For the moment, the Go AWS library in use does not use the newer DNS based bucket routing.
bucket	yes	The bucket name in which you want to store the registry's data.
encrypt	no	Specifies whether the registry stores the image in encrypted format or not. A boolean value. The default is false.
secure	no	Indicates whether to use HTTPS instead of HTTP. A boolean value. The default is false.
v4auth	no	Indicates whether the registry uses Version 4 of AWS's authentication. Generally, you should set this to true. By default, this is false.
chunksize	no	The S3 API requires multipart upload chunks to be at least 5MB. This value should be a number that is larger than 5*1024*1024.
rootdirectory	no	This is a prefix that will be applied to all S3 keys to allow you to segment data in your bucket if necessary.

Maintenance

Currently the registry can perform one maintenance function: upload purging. This and future maintenance functions which are related to storage can be configured under the maintenance section.

Upload Purging

Upload purging is a background process that periodically removes orphaned files from the upload directories of the registry. Upload purging is enabled by default. To configure upload directory purging, the following parameters must be set.

Parameter	Required	Description
enabled	yes	Set to true to enable upload purging. Default=true.
age	yes	Upload directories which are older than this age will be deleted. Default=168h (1 week)
interval	yes	The interval between upload directory purging. Default=24h.
dryrun	yes	dryrun can be set to true to obtain a summary of what directories will be deleted. Default=false.

Note: age and interval are strings containing a number with optional fraction and a unit suffix: e.g. 45m, 2h10m, 168h (1 week).

auth

auth:
	silly:
		realm: silly-realm
		service: silly-service
	token:
		realm: token-realm
		service: token-service
		issuer: registry-token-issuer
		rootcertbundle: /root/certs/bundle

The auth option is optional as there are use cases (i.e. a mirror that only permits pulls) for which authentication may not be desired. There are currently 2 possible auth providers, silly and token. You can configure only one auth provider.

silly

The silly auth is only for development purposes. It simply checks for the existence of the Authorization header in the HTTP request. It has no regard for the header's value. If the header does not exist, the silly auth responds with a challenge response, echoing back the realm, service, and scope that access was denied for.

The following values are used to configure the response:

Parameter	Required	Description
realm	yes	The realm in which the registry server authenticates.
service	yes	The service being authenticated.

token

Token based authentication allows the authentication system to be decoupled from the registry. It is a well established authentication paradigm with a high degree of security.

Parameter	Required	Description
realm	yes	The realm in which the registry server authenticates.
service	yes	The service being authenticated.
issuer	yes	The name of the token issuer. The issuer inserts this into the token so it must match the value configured for the issuer.
rootcertbundle	yes	The absolute path to the root certificate bundle. This bundle contains the public part of the certificates that is used to sign authentication tokens.

For more information about Token based authentication configuration, see the [specification.]

middleware

The middleware option is optional. Use this option to inject middleware at named hook points. All middlewares must implement the same interface as the object they're wrapping. This means a registry middleware must implement the distribution.Namespace interface, repository middleware must implement distribution.Respository, and storage middleware must implement driver.StorageDriver.

Currently only one middleware, cloudfront, a storage middleware, is supported in the registry implementation.

middleware:
	registry:
		- name: ARegistryMiddleware
		  options:
			foo: bar
	repository:
		- name: ARepositoryMiddleware
		  options:
			foo: bar
	storage:
		- name: cloudfront
		  options:
			baseurl: https://my.cloudfronted.domain.com/
			privatekey: /path/to/pem
			keypairid: cloudfrontkeypairid
			duration: 3000

Each middleware entry has name and options entries. The name must correspond to the name under which the middleware registers itself. The options field is a map that details custom configuration required to initialize the middleware. It is treated as a map[string]interface{}. As such, it supports any interesting structures desired, leaving it up to the middleware initialization function to best determine how to handle the specific interpretation of the options.

cloudfront

Parameter	Required	Description
baseurl	yes	SCHEME://HOST[/PATH] at which Cloudfront is served.
privatekey	yes	Private Key for Cloudfront provided by AWS.
keypairid	yes	Key pair ID provided by AWS.
duration	no	Duration for which a signed URL should be valid.

reporting

reporting:
	bugsnag:
		apikey: bugsnagapikey
		releasestage: bugsnagreleasestage
		endpoint: bugsnagendpoint
	newrelic:
		licensekey: newreliclicensekey
		name: newrelicname
		verbose: true

The reporting option is optional and configures error and metrics reporting tools. At the moment only two services are supported, New Relic and Bugsnag, a valid configuration may contain both.

bugsnag

Parameter	Required	Description
apikey	yes	API Key provided by Bugsnag
releasestage	no	Tracks where the registry is deployed, for example, production,staging, or development.
endpoint	no	Specify the enterprise Bugsnag endpoint.

newrelic

Parameter	Required	Description
licensekey	yes	License key provided by New Relic.
name	no	New Relic application name.
verbose	no	Enable New Relic debugging output on stdout.

http

http:
	addr: localhost:5000
	net: tcp
	prefix: /my/nested/registry/
	secret: asecretforlocaldevelopment
	tls:
		certificate: /path/to/x509/public
		key: /path/to/x509/private
    clientcas:
      - /path/to/ca.pem
      - /path/to/another/ca.pem
	debug:
		addr: localhost:5001

The http option details the configuration for the HTTP server that hosts the registry.

Parameter	Required	Description
addr	yes	The address for which the server should accept connections. The form depends on a network type (see net option): HOST:PORT for tcp and FILE for a unix socket.
net	no	The network which is used to create a listening socket. Known networks are unix and tcp. The default empty value means tcp.
prefix	no	If the server does not run at the root path use this value to specify the prefix. The root path is the section before v2. It should have both preceding and trailing slashes, for example /path/.
secret	yes	A random piece of data. This is used to sign state that may be stored with the client to protect against tampering. For production environments you should generate a random piece of data using a cryptographically secure random generator.

tls

The tls struct within http is optional. Use this to configure TLS for the server. If you already have a server such as Nginx or Apache running on the same host as the registry, you may prefer to configure TLS termination there and proxy connections to the registry server.

Parameter	Required	Description
certificate	yes	Absolute path to x509 cert file
key	yes	Absolute path to x509 private key file.
clientcas	no	An array of absolute paths to a x509 CA file

debug

The debug option is optional . Use it to configure a debug server that can be helpful in diagnosing problems. The debug endpoint can be used for monitoring registry metrics and health, as well as profiling. Sensitive information may be available via the debug endpoint. Please be certain that access to the debug endpoint is locked down in a production environment.

The debug section takes a single, required addr parameter. This parameter specifies the HOST:PORT on which the debug server should accept connections.

notifications

notifications:
	endpoints:
		- name: alistener
		  disabled: false
		  url: https://my.listener.com/event
		  headers: <http.Header>
		  timeout: 500
		  threshold: 5
		  backoff: 1000

The notifications option is optional and currently may contain a single option, endpoints.

endpoints

Endpoints is a list of named services (URLs) that can accept event notifications.

Parameter	Required	Description
name	yes	A human readable name for the service.
disabled	no	A boolean to enable/disable notifications for a service.
url	yes	The URL to which events should be published.
headers	yes	Static headers to add to each request.
timeout	yes	An HTTP timeout value. This field takes a positive integer and an optional suffix indicating the unit of time. Possible units are: ns (nanoseconds) us (microseconds) ms (milliseconds) s (seconds) m (minutes) h (hours) If you omit the suffix, the system interprets the value as nanoseconds.
threshold	yes	An integer specifying how long to wait before backing off a failure.
backoff	yes	How long the system backs off before retrying. This field takes a positive integer and an optional suffix indicating the unit of time. Possible units are: ns (nanoseconds) us (microseconds) ms (milliseconds) s (seconds) m (minutes) h (hours) If you omit the suffix, the system interprets the value as nanoseconds.

redis

redis:
	addr: localhost:6379
	password: asecret
	db: 0
	dialtimeout: 10ms
	readtimeout: 10ms
	writetimeout: 10ms
	pool:
		maxidle: 16
		maxactive: 64
		idletimeout: 300s

Declare parameters for constructing the redis connections. Registry instances may use the Redis instance for several applications. The current purpose is caching information about immutable blobs. Most of the options below control how the registry connects to redis. You can control the pool's behavior with the pool subsection.

Parameter	Required	Description
addr	yes	Address (host and port) of redis instance.
password	no	A password used to authenticate to the redis instance.
db	no	Selects the db for each connection.
dialtimeout	no	Timeout for connecting to a redis instance.
readtimeout	no	Timeout for reading from redis connections.
writetimeout	no	Timeout for writing to redis connections.

pool

pool:
	maxidle: 16
	maxactive: 64
	idletimeout: 300s

Configure the behavior of the Redis connection pool.

Parameter	Required	Description
maxidle	no	Sets the maximum number of idle connections.
maxactive	no	sets the maximum number of connections that should be opened before blocking a connection request.
idletimeout	no	sets the amount time to wait before closing inactive connections.

Example: Development configuration

The following is a simple example you can use for local development:

version: 0.1
log:
	level: debug
storage:
    filesystem:
        rootdirectory: /tmp/registry-dev
http:
    addr: localhost:5000
    secret: asecretforlocaldevelopment
    debug:
        addr: localhost:5001

The above configures the registry instance to run on port 5000, binding to localhost, with the debug server enabled. Registry data storage is in the /tmp/registry-dev directory. Logging is in debug mode, which is the most verbose.

A similar simple configuration is available at config.yml. Both are generally useful for local development.

Example: Middleware configuration

This example illustrates how to configure storage middleware in a registry. Middleware allows the registry to serve layers via a content delivery network (CDN). This is useful for reducing requests to the storage layer.

Currently, the registry supports Amazon Cloudfront. You can only use Cloudfront in conjunction with the S3 storage driver.

Parameter	Description
name	The storage middleware name. Currently cloudfront is an accepted value.
disabled	Set to false to easily disable the middleware.
options:	A set of key/value options to configure the middleware. baseurl: The Cloudfront base URL. privatekey: The location of your AWS private key on the filesystem. keypairid: The ID of your Cloudfront keypair. duration: The duration in minutes for which the URL is valid. Default is 20.

The following example illustrates these values:

middleware:
    storage:
        - name: cloudfront
          disabled: false
          options:
             baseurl: http://d111111abcdef8.cloudfront.net
             privatekey: /path/to/asecret.pem
             keypairid: asecret
             duration: 60

Note

: Cloudfront keys exist separately to other AWS keys. See the documentation on AWS credentials for more information.