Fluent::AwsElasticsearchServiceOutput
This output plugin to post to "Amazon Elasticsearch Service".
Installation
Add this line to your application's Gemfile:
gem 'fluent-plugin-aws-elasticsearch-service'
Usage
In your fluentd configration, use type aws-elasticsearch-service
.
example:
<source>
type tail
format apache
time_format "%d/%b/%Y:%T %z"
path "/var/log/nginx/access.log"
pos_file "/var/log/td-agent/nginx.access.pos"
tag "es.nginx.access"
</source>
<match es.**>
type "aws-elasticsearch-service"
type_name "access_log"
logstash_format true
include_tag_key true
tag_key "@log_name"
flush_interval 1s
<endpoint>
url https://CLUSTER_ENDPOINT_URL
region eu-west-1
# access_key_id "secret"
# secret_access_key "seekret"
</endpoint>
</match>
IAM
If you do not wish to use credentials in your configuration via the access_key_id
and secret_access_key
options you should use IAM policies.
The first step is to assign an IAM instance role ROLE
to your EC2 instances. Name it appropriately. The role should contain no policy: we're using the possession of the role as the authenticating factor and placing the policy against the ES cluster.
You should then configure a policy for the ES cluster policy thus, with appropriate substitutions for the capitalized terms:
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Principal": {
"AWS": "arn:aws:iam::ACCOUNT:role/ROLE"
},
"Action": "es:*",
"Resource": "arn:aws:es:eu-west-1:ACCOUNT:domain/ES_DOMAIN/*"
},
{
"Effect": "Allow",
"Principal": {
"AWS": "*"
},
"Action": "es:*",
"Resource": "arn:aws:es:eu-west-1:ACCOUNT:domain/ES_DOMAIN/*",
"Condition": {
"IpAddress": {
"aws:SourceIp": [
"1.2.3.4/32",
"5.6.7.8/32"
]
}
}
}
]
}
This will allow your fluentd hosts (by virtue of the possession of the role) and any traffic coming from the specified IP addresses (you querying Kibana) to access the various endpoints. Whilst not ideally secure (both the fluentd and Kibana boxes should ideally be restricted to the verbs they require) it should allow you to get up and ingesting logs without anything getting in your way, before you tighten down the policy.
Additionally, you can use an STS assumed role as the authenticating factor and instruct the plugin to assume this role. This is useful for cross-account access and when assigning a standard role is not possible. The endpoint configuration looks like:
<endpoint>
url https://CLUSTER_ENDPOINT_URL
region eu-west-1
assume_role_arn arn:aws:sts::ACCOUNT:role/ROLE
assume_role_session_name SESSION_ID
</endpoint>
The policy attached to your AWS Elasticsearch cluster then becomes something like:
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Principal": {
"AWS": "arn:aws:sts::ACCOUNT:assumed-role/ROLE/SESSION_ID"
},
"Action": "es:*",
"Resource": "arn:aws:es:eu-west-1:ACCOUNT:domain/ES_DOMAIN/*"
}
]
}
You'll need to ensure that the environment in which the fluentd plugin runs has the capability to assume this role, by attaching a policy something like this to the instance profile:
{
"Version": "2012-10-17",
"Statement": {
"Effect": "Allow",
"Action": "sts:AssumeRole",
"Resource": "arn:aws:iam::ACCOUNT:role/ROLE"
}
}
Troubleshooting
-
"Elasticsearch::Transport::Transport::Errors::Forbidden" error="[403]" even after verifying the access keys/roles/policies.
- Ensure you don't have a trailing slash on the endpoint URL in your fluentd configuration file (see CLUSTER_ENDPOINT_URL above).
-
"ElasticsearchIllegalArgumentException[explicit index in bulk is not allowed]"
Development
After checking out the repo, run bin/setup
to install dependencies. You can also run bin/console
for an interactive prompt that will allow you to experiment.
To install this gem onto your local machine, run bundle exec rake install
. To release a new version, update the version number in version.rb
, and then run bundle exec rake release
, which will create a git tag for the version, push git commits and tags, and push the .gem
file to rubygems.org.
Contributing
Bug reports and pull requests are welcome on GitHub at https://github.com/atomita/fluent-plugin-aws-elasticsearch-service. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.
License
The gem is available as open source under the terms of the MIT License.