AWS Cloud Plugin for Elasticsearch

The Amazon Web Service (AWS) Cloud plugin allows to use AWS API for the unicast discovery mechanism and add S3 repositories.

In order to install the plugin, simply run: bin/plugin -install elasticsearch/elasticsearch-cloud-aws/2.0.0.RC1.

• For master elasticsearch versions, look at master branch.
• For 1.2.x elasticsearch versions, look at es-1.2 branch.
• For 1.1.x elasticsearch versions, look at es-1.1 branch.
• For 1.0.x elasticsearch versions, look at es-1.0 branch.
• For 0.90.x elasticsearch versions, look at es-0.90 branch.

AWS Cloud Plugin	elasticsearch	Release date
3.0.0-SNAPSHOT	master	XXXX-XX-XX

Please read documentation relative to the version you are using:

• 3.0.0-SNAPSHOT

Generic Configuration

The plugin will automatically use the instance level security credentials (as of 1.7.0), but they can be provided explicitly using cloud.aws.access_key and cloud.aws.secret_key:

cloud:
    aws:
        access_key: AKVAIQBF2RECL7FJWGJQ
        secret_key: vExyMThREXeRMm/b/LRzEB8jWwvzQeXgjqMX+6br

Region

The cloud.aws.region can be set to a region and will automatically use the relevant settings for both ec2 and s3. The available values are:

• us-east (us-east-1)
• us-west (us-west-1)
• us-west-1
• us-west-2
• ap-southeast (ap-southeast-1)
• ap-southeast-1
• ap-southeast-2
• ap-northeast (ap-northeast-1)
• eu-west (eu-west-1)
• sa-east (sa-east-1).

EC2 Discovery

ec2 discovery allows to use the ec2 APIs to perform automatic discovery (similar to multicast in non hostile multicast environments). Here is a simple sample configuration:

cloud:
    aws:
        access_key: AKVAIQBF2RECL7FJWGJQ
        secret_key: vExyMThREXeRMm/b/LRzEB8jWwvzQeXgjqMX+6br

discovery:
    type: ec2

The following are a list of settings (prefixed with discovery.ec2) that can further control the discovery:

• groups: Either a comma separated list or array based list of (security) groups. Only instances with the provided security groups will be used in the cluster discovery. (NOTE: You could provide either group NAME or group ID.)
• host_type: The type of host type to use to communicate with other instances. Can be one of private_ip, public_ip, private_dns, public_dns. Defaults to private_ip.
• availability_zones: Either a comma separated list or array based list of availability zones. Only instances within the provided availability zones will be used in the cluster discovery.
• any_group: If set to false, will require all security groups to be present for the instance to be used for the discovery. Defaults to true.
• ping_timeout: How long to wait for existing EC2 nodes to reply during discovery. Defaults to 3s. If no unit like ms, s or m is specified, milliseconds are used.

Filtering by Tags

The ec2 discovery can also filter machines to include in the cluster based on tags (and not just groups). The settings to use include the discovery.ec2.tag. prefix. For example, setting discovery.ec2.tag.stage to dev will only filter instances with a tag key set to stage, and a value of dev. Several tags set will require all of those tags to be set for the instance to be included.

One practical use for tag filtering is when an ec2 cluster contains many nodes that are not running elasticsearch. In this case (particularly with high ping_timeout values) there is a risk that a new node's discovery phase will end before it has found the cluster (which will result in it declaring itself master of a new cluster with the same name - highly undesirable). Tagging elasticsearch ec2 nodes and then filtering by that tag will resolve this issue.

Automatic Node Attributes

Though not dependent on actually using ec2 as discovery (but still requires the cloud aws plugin installed), the plugin can automatically add node attributes relating to ec2 (for example, availability zone, that can be used with the awareness allocation feature). In order to enable it, set cloud.node.auto_attributes to true in the settings.

S3 Repository

The S3 repository is using S3 to store snapshots. The S3 repository can be created using the following command:

$ curl -XPUT 'http://localhost:9200/_snapshot/my_s3_repository' -d '{
    "type": "s3",
    "settings": {
        "bucket": "my-bucket-name",
        "region": "us-west"
    }
}'

The following settings are supported:

• bucket: The name of the bucket to be used for snapshots. (Mandatory)
• region: The region where bucket is located. Defaults to US Standard
• base_path: Specifies the path within bucket to repository data. Defaults to root directory.
• access_key: The access key to use for authentication. Defaults to value of cloud.aws.access_key.
• secret_key: The secret key to use for authentication. Defaults to value of cloud.aws.secret_key.
• concurrent_streams: Throttles the number of streams (per node) preforming snapshot operation. Defaults to 5.
• chunk_size: Big files can be broken down into chunks during snapshotting if needed. The chunk size can be specified in bytes or by using size value notation, i.e. 1g, 10m, 5k. Defaults to 100m.
• compress: When set to true metadata files are stored in compressed format. This setting doesn't affect index files that are already compressed by default. Defaults to false.

The S3 repositories are using the same credentials as the rest of the S3 services provided by this plugin (discovery and gateway). They can be configured the following way:

cloud:
    aws:
        access_key: AKVAIQBF2RECL7FJWGJQ
        secret_key: vExyMThREXeRMm/b/LRzEB8jWwvzQeXgjqMX+6br

Multiple S3 repositories can be created. If the buckets require different credentials, then define them as part of the repository settings.

Recommended S3 Permissions

In order to restrict the Elasticsearch snapshot process to the minimum required resources, we recommend using Amazon IAM in conjunction with pre-existing S3 buckets. Here is an example policy which will allow the snapshot access to an S3 bucket named "snaps.example.com". This may be configured through the AWS IAM console, by creating a Custom Policy, and using a Policy Document similar to this (changing snaps.example.com to your bucket name).

{
    "Statement": [
        {
            "Action": [
                "s3:ListBucket"
            ],
            "Effect": "Allow",
            "Resource": [
                "arn:aws:s3:::snaps.example.com"
            ]
        },
        {
            "Action": [
                "s3:GetObject",
                "s3:PutObject",
                "s3:DeleteObject"
            ],
            "Effect": "Allow",
            "Resource": [
                "arn:aws:s3:::snaps.example.com/*"
            ]
        }
    ],
    "Version": "2012-10-17"
}

You may further restrict the permissions by specifying a prefix within the bucket, in this example, named "foo".

{
    "Statement": [
        {
            "Action": [
                "s3:ListBucket"
            ],
            "Condition": {
                "StringLike": {
                    "s3:prefix": [
                        "foo/*"
                    ]
                }
            },
            "Effect": "Allow",
            "Resource": [
                "arn:aws:s3:::snaps.example.com"
            ]
        },
        {
            "Action": [
                "s3:GetObject",
                "s3:PutObject",
                "s3:DeleteObject"
            ],
            "Effect": "Allow",
            "Resource": [
                "arn:aws:s3:::snaps.example.com/foo/*"
            ]
        }
    ],
    "Version": "2012-10-17"
}

The bucket needs to exist to register a repository for snapshots. If you did not create the bucket then the repository registration will fail. If you want elasticsearch to create the bucket instead, you can add the permission to create a specific bucket like this:

{
   "Action": [
      "s3:CreateBucket"
   ],
   "Effect": "Allow",
   "Resource": [
      "arn:aws:s3:::snaps.example.com"
   ]
}

Testing

Integrations tests in this plugin require working AWS configuration and therefore disabled by default. Three buckets and two iam users have to be created. The first iam user needs access to two buckets in different regions and the final bucket is exclusive for the other iam user. To enable tests prepare a config file elasticsearch.yml with the following content:

cloud:
    aws:
        access_key: AKVAIQBF2RECL7FJWGJQ
        secret_key: vExyMThREXeRMm/b/LRzEB8jWwvzQeXgjqMX+6br

repositories:
    s3:
        bucket: "bucket-name"
        region: "us-west-2"
        private-bucket:
            bucket: <bucket not accessible by default key>
            access_key: <access key>
            secret_key: <access key>
        remote-bucket:
            bucket: <bucket in other region>
            region: <region>

Replace all occurrences of access_key, secret_key, bucket and region with your settings. Please, note that the test will delete all snapshot/restore related files in the specified buckets.

To run test:

mvn -Dtests.aws=true -Des.config=/path/to/config/file/elasticsearch.yml clean test

License

This software is licensed under the Apache 2 license, quoted below.

Copyright 2009-2014 Elasticsearch <http://www.elasticsearch.org>

Licensed under the Apache License, Version 2.0 (the "License"); you may not
use this file except in compliance with the License. You may obtain a copy of
the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
License for the specific language governing permissions and limitations under
the License.