The Ansible AWS S3 core module now supports Ceph RGW S3. The patch was upstream today and it will be included in Ansible 2.2

This post will introduce the new RGW S3 support in Ansible together with the required bits to run Ansible playbooks handling S3 use cases in Ceph Jewel.

The Ansible project

Ansible is a simple IT automation engine that automates cloud provisioning, configuration management, application deployment and intra-service orchestration among many other IT needs.

Ansible works by connecting to nodes (SSH/WinRM) and pushing out small programs, called 'Ansible modules' to them. These programs are written to be resource models of the desired state of the system. Ansible then executes these modules and removes them when finished.

Ansible uses playbooks to orchestrate the infrastructure with very detailed control. Those playbooks define configuration policies and orchestration workflows. They are a YAML definition of automation tasks that describe how a particular piece of automation should be done.

Playbooks are modeled as a collection of plays, each of which defines a set of tasks to be executed on a group of remote hosts. A play also defines the environment where the tasks will be executed.

Ansible modules ensure indempotence so it is possible running the same tasks over and over without affecting the final result.

Using the Ansible AWS S3 core module with Ceph

The Ceph RGW S3 support is part of the Amazon S3 core module in Ansible. The AWS S3 core module allows the user to manage S3 buckets and the objects within them. It includes support for creating and deleting both objects and buckets, retrieving objects as files or strings and generating download links.

The patch leverages the AWS S3 use cases without any restriction or limitation with regions, URLs, etc.

To enable the RGW S3 flavour in the S3 core module you set the 'rgw' boolean option to 'true' and the 's3_url' string option to the RGW S3 server.

controller:~$ ansible rgw.test.node -m s3 -a \
"mode=list bucket=my-bucket s3_url=http://rgw.test.server:8000 rgw=true"

The 's3_url' option is mandatory in the RGW S3 flavour.

Testing the RGW S3 core module flavour via Playbook

This Playbook example tests the RGW S3 flavour in a simple three boxes network ('controller', 'rgw.test.node' and 'rgw.test.server')

The 'controller' host is the box running the Ansible engine.

The 'rgw.test.node' is the host connecting to the Ceph RGW server and running the S3 use cases.

The 'rgw.test.server' is the Ceph RGW S3 server.

Running the testing Playbook...

controller:~$ ansible-playbook playbook-test-rgw-s3-core-module.yml

PLAY [all] *********************************************************************

TASK [setup] *******************************************************************
ok: [rgw.test.node]

TASK [create test_file test-file.txt] ******************************************
changed: [rgw.test.node]

TASK [put s3_bucket_items my-test-object-1] ************************************
changed: [rgw.test.node] => (item=my-test-object-1.txt)
changed: [rgw.test.node] => (item=my-test-object-2.txt)

TASK [get s3_bucket_items] *****************************************************
ok: [rgw.test.node]

TASK [download s3_bucket_items] ************************************************
changed: [rgw.test.node] => (item=my-test-object-1.txt)
changed: [rgw.test.node] => (item=my-test-object-2.txt)

TASK [remove s3_bucket_and_content] ********************************************
changed: [rgw.test.node]

PLAY RECAP *********************************************************************
rgw.test.node              : ok=6    changed=4    unreachable=0    failed=0

As expected, the Playbook runs the 'create', 'upload', 'list', 'download' and 'remove' S3 use cases for buckets and objects. Adding the '-v' switch will show a more verbose output.


All examples, modules and playbooks related to RGW S3 were tested on the new Ceph Jewel release.

Beyond of the RGW S3 support in the AWS S3 core module you could be interested in Ansible Playbooks to set up and configure Ceph clusters automatically. You can find those Playbooks in ceph/ceph-ansible with general support for Monitors, OSDs, MDSs and RGW.

The primary documentation for Ansible is available here. I found the Ansible whitepapers a great resource too.


My work in Ansible is sponsored by Outscale and has been made possible by Igalia and the invaluable help of the Ansible community. Thank you all!


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