README.md

Overview

This plugin provides the ability for your RabbitMQ server to perform authentication (determining who can log in) and authorisation (determining what permissions they have) by making requests to an HTTP server.

This plugin can put a significant amount of load on its backing service. We recommend using it together with rabbitmq_auth_backend_cache with a reasonable caching interval (e.g. 1-3 minutes).

RabbitMQ Version Requirements

This plugin is distributed with RabbitMQ.

Enabling the Plugin

Like all RabbitMQ plugins, this plugin must be enabled before it can be used:

rabbitmq-plugins enable rabbitmq_auth_backend_http

Configuring the Plugin

To use this backend exclusively, use the following snippet in rabbitmq.conf (currently in master)

auth_backends.1 = http

Or, in the classic config format (rabbitmq.config, prior to 3.7.0) or advanced.config:

[{rabbit, [{auth_backends, [rabbit_auth_backend_http]}]}].

See RabbitMQ Configuration guide and Access Control guide for more information.

You need to configure the plugin to know which URIs to point at and which HTTP method to use.

Below is a minimal configuration file example.

In rabbitmq.conf:

auth_backends.1 = http
auth_http.http_method   = post
auth_http.user_path     = http://some-server/auth/user
auth_http.vhost_path    = http://some-server/auth/vhost
auth_http.resource_path = http://some-server/auth/resource
auth_http.topic_path    = http://some-server/auth/topic

In the advanced.config format:

[
    {rabbit, [{auth_backends, [rabbit_auth_backend_http]}]},
    {rabbitmq_auth_backend_http,
    [{http_method,   post},
    {user_path,     "http(s)://some-server/auth/user"},
    {vhost_path,    "http(s)://some-server/auth/vhost"},
    {resource_path, "http(s)://some-server/auth/resource"},
    {topic_path,    "http(s)://some-server/auth/topic"}]}
].

By default http_method configuration is GET for backwards compatibility. It's recommended to use POST requests to avoid credentials logging.

What Must My Web Server Do?

This plugin requires that your web server respond to requests in a certain predefined format. It will make GET (by default) or POST requests against the URIs listed in the configuration file. It will add query string (for GET requests) or a URL-encoded request body (for POST requests) parameters as follows:

user_path

• username: the name of the user
• password: the password provided (may be missing if e.g. rabbitmq-auth-mechanism-ssl is used)

Note: This request may include additional http request parameters in addition to the ones listed above. For instance, if the user accessed RabbitMQ via the MQTT protocol, it is expected client_id and vhost request parameters too.

vhost_path

• username: the name of the user
• vhost: the name of the virtual host being accessed
• ip: the client ip address

Note that you cannot create arbitrary virtual hosts using this plugin; you can only determine whether your users can see / access the ones that exist.

resource_path

• username: the name of the user
• vhost: the name of the virtual host containing the resource
• resource: the type of resource (exchange, queue, topic)
• name: the name of the resource
• permission:the access level to the resource (configure, write, read): see the Access Control guide for their meaning

Note: This request may include additional http request parameters in addition to the ones listed above. For instance, if the user accessed RabbitMQ via the MQTT protocol, it is expected client_id request parameter too.

topic_path

• username: the name of the user
• vhost: the name of the virtual host containing the resource
• resource: the type of resource (topic in this case)
• name: the name of the exchange
• permission: the access level to the resource (write or read)
• routing_key: the routing key of a published message (when the permission is write) or routing key of the queue binding (when the permission is read)

See topic authorisation for more information about topic authorisation.

Your web server should always return HTTP 200 OK, with a body containing:

• deny: deny access to the user / vhost / resource
• allow: allow access to the user / vhost / resource
• allow [list of tags] (for user_path only): allow access, and mark the user as an having the tags listed

Using TLS/HTTPS

If your Web server uses HTTPS and certificate verification, you need to configure the plugin to use a CA and client certificate/key pair using the rabbitmq_auth_backend_http.ssl_options config variable:

[
    {rabbit, [{auth_backends, [rabbit_auth_backend_http]}]},
    {rabbitmq_auth_backend_http,
    [{http_method,   post},
    {user_path,     "https://some-server/auth/user"},
    {vhost_path,    "https://some-server/auth/vhost"},
    {resource_path, "https://some-server/auth/resource"},
    {topic_path,    "https://some-server/auth/topic"},
    {ssl_options,
        [{cacertfile, "/path/to/cacert.pem"},
        {certfile,   "/path/to/client/cert.pem"},
        {keyfile,    "/path/to/client/key.pem"},
        {verify,     verify_peer},
        {fail_if_no_peer_cert, true}]}]}
].

It is recommended to use TLS for authentication and enable peer verification.

Wildcard Certificates

If the certificate of your Web Server should be matched against a wildcard certificate in your cacertfile, the following option must be added to the ssl_options:

{customize_hostname_check, [{match_fun,public_key:pkix_verify_hostname_match_fun(https)}]}

Debugging

Enable debug logging to see what the backend service receives. Look for log messages containing "rabbit_auth_backend_http failed".

Example Apps

There are example backend services available in Python, PHP, Spring Boot, ASP.NET Web API.

See examples README for more information.