Readonly REST Elasticsearch Plugin

Expose the high performance HTTP server embedded in Elasticsearch directly to the public, safely blocking any attempt to delete or modify your data.

In other words... no more proxies! Yay Ponies!

Getting started

1. Install the plugin

List of other supported Elasticsearch versions: releases tab. If you need a build for a specific ES version, just open an issue!

ES_VERSION=2.4.1
bin/plugin install https://github.com/sscarduzio/elasticsearch-readonlyrest-plugin/releases/download/v1.10.0_es-v$ES_VERSION/elasticsearch-readonlyrest-v1.11.0_es-v$ES_VERSION.zip

2. Configuration

Append either of these snippets to conf/elasticsearch.yml

USE CASE 0: Enable SSL globally

Remember to enable SSL whenever you use HTTP basic auth or API keys so your credentials can't be stolen.

readonlyrest:
    enable: true
    
    ssl:
      enable: true
      keystore_file: "/elasticsearch/plugins/readonlyrest/keystore.jks"
      keystore_pass: readonlyrest
      key_pass: readonlyrest

USE CASE 1: Full access from localhost + RO to catalogue-* indices from elsewhere

readonlyrest:
    enable: true
    response_if_req_forbidden: Sorry, your request is forbidden.
    
    access_control_rules:

    - name: Accept all requests from localhost
      type: allow
      hosts: [127.0.0.1]

    - name: Just certain indices, and read only
      type: allow
      actions: ["indices:data/read/*"]
      indices: ["<no-index>", "product_catalogue-*"] # index aliases are taken in account!

The <no-index> is for matching those generic requests that don't actually involve an index (e.g. get cluster state). More about this in the wiki.

USE CASE 2: Multiuser Kibana + Authenticated Logstash (various permission levels)

# remember to set the right CORS origin (or disable it, if you're brave). See https://github.com/elastic/kibana/issues/6719
http.cors.enabled: true
http.cors.allow-origin: /https?:\/\/localhost(:[0-9]+)?/

readonlyrest:
    enable: true
    
    response_if_req_forbidden: Forbidden by ReadonlyREST ES plugin
    
    access_control_rules:

    - name: "Logstash can write and create its own indices"
      # auth_key is good for testing, but replace it with `auth_key_sha1`!
      auth_key: logstash:logstash
      type: allow
      actions: ["indices:data/read/*","indices:data/write/*","indices:admin/template/*","indices:admin/create"]
      indices: ["logstash-*", "<no-index>"]

    - name: Kibana Server (we trust this server side component, full access granted via HTTP authentication)
      # auth_key is good for testing, but replace it with `auth_key_sha1`!
      auth_key: admin:passwd3
      type: allow

    - name: Developer (reads only logstash indices, but can create new charts/dashboards)
      # auth_key is good for testing, but replace it with `auth_key_sha1`!
      auth_key: dev:dev
      type: allow
      kibana_access: ro+
      indices: ["<no-index>", ".kibana*", "logstash*", "default"]

Now activate authentication in Kibana server: let the Kibana daemon connect to ElasticSearch in privileged mode.

• edit the kibana configuration file: kibana.yml and add the following:

elasticsearch.username: "admin"
elasticsearch.password: "passwd3"

This is secure because the users connecting from their browsers will be asked to login separately anyways.

Now activate authenticatoin in Logstash: (follow the docs, it's very similar to Kibana!)

USE CASE 3: Group-based access control

readonlyrest:
    enable: true
    response_if_req_forbidden: Forbidden by ReadonlyREST ES plugin
    
    access_control_rules:

    - name: Accept requests from users in group team1 on index1
      type: allow
      groups: ["team1"]
      uri_re: ^/index1/.*

    - name: Accept requests from users in group team2 on index2
      type: allow
      groups: ["team2"]
      uri_re: ^/index2/.*

    - name: Accept requests from users in groups team1 or team2 on index3
      type: allow
      groups: ["team1", "team2"]
      uri_re: ^/index3/.*
    
    users:
    
    - username: alice
      auth_key: alice:p455phrase
      groups: ["team1"]
      
    - username: bob
      auth_key: bob:s3cr37
      groups: ["team2", "team4"]
      
    - username: claire
      auth_key_sha1: 2bc37a406bd743e2b7a4cb33efc0c52bc2cb03f0 #claire:p455key
      groups: ["team1", "team5"]

3. Restart Elasticsearch

For other use cases and finer access control have a look at the full list of supported rules

Important!

Before going to production, read this.

disallow explicit indices

When you want to restrict access to certain indices, in order to prevent the user from overriding the index which has been specified in the URL, add this setting to the config.yml file:

rest.action.multi.allow_explicit_index: false

The default value is true, but when set to false, Elasticsearch will reject requests that have an explicit index specified in the request body.

Use hashed credentials

Plain text auth_key is is great for testing, but remember to replace it with auth_key_sha1!

Key Features

Zero external dependencies: tiny memory overhead, blazing fast networking 🚀

Other security plugins are replacing the high performance, Netty based, embedded REST API of Elasticsearch with Tomcat, Jetty or other cumbersome XML based JEE madness.

This plugin instead is just a lightweight pure-Java filtering layer. Even the SSL layer is provided as an extra Netty transport handler.

Less moving parts

Some suggest to spin up a new HTTP proxy (Varnish, NGNix, HAProxy) between ES and clients to prevent malicious access. This is a bad idea for two reasons:

• You're introducing more complexity in your architecture.
• Reasoning about security at HTTP level is risky, flaky and less granular than controlling access at the internal ElasticSearch protocol level.

The only clean way to do the access control is AFTER ElasticSearch has parsed the queries.

Just set a few rules with this plugin and confidently open it up to the external world.

An easy, flexible access control list

Build your ACL from simple building blocks (rules) i.e.:

IP level Rules

• hosts a list of origin IP addresses or subnets

HTTP level rules

• api_keys a list of api keys passed in via header X-Api-Key
• methods a list of HTTP methods
• accept_x-forwarded-for_header interpret the X-Forwarded-For header as origin host (useful for AWS ELB and other reverse proxies)
• auth_key_sha1 HTTP Basic auth (credentials stored as hashed strings).
• uri_re Match the URI path as a regex.

ElasticSearch internal protocol level rules

• indices indices (aliases and wildcards work)
• actions list of ES actions (e.g. "cluster:" , "indices:data/write/", "indices:data/read*")

ElasticSearh level macro-rules

• kibana_access captures the read-only, read-only + new visualizations/dashboards, read-write use cases of Kibana.

All the available rules in detail

• List of ACL block rules supported
• List of Actions and their meaning

History

This project was incepted in this StackOverflow thread.

Credits

Thanks Ivan Brusic for publishing this guide