Ansistrano

ansistrano.deploy and ansistrano.rollback are Ansible roles to easily manage the deployment process for scripting applications such as PHP, Python and Ruby. It's an Ansible port for Capistrano.

History

Capistrano is a remote server automation tool and it's currently in Version 3. Version 2.0 was originally thought in order to deploy RoR applications. With additional plugins, you were able to deploy non Rails applications such as PHP and Python, with different deployment strategies, stages and much more. I loved Capistrano v2. I have used it a lot. I developed a plugin for it.

Capistrano 2 was a great tool and it still works really well. However, it is not maintained anymore since the original team is working in v3. This new version does not have the same set of features so it is less powerful and flexible. Besides that, other new tools are becoming easier to use in order to deploy applications, such as Ansible.

So, I have decided to stop using Capistrano because v2 is not maintained, v3 does not have enough features, and I can do everything Capistrano was doing with Ansible. If you are looking for alternatives, check Fabric or Chef Solo.

Project name

Ansistrano comes from Ansible + Capistrano, easy, isn't it?

Early adopters

If you were an early adopter, you should know we have broken BC by moving from using ansistrano_custom_tasks_path to individual and specific files per step. See "Role Variables". The role displays a warning if the variable is defined and although your old playbooks may still run with no errors, you will see that your code is uploaded but custom tasks are not run.

Ansistrano anonymous usage stats

We have recently added an extra optional step in Ansistrano so that we can know how many people are deploying their applications with our project. Unfortunately, Ansible Galaxy does not provide any numbers on usage or downloads so this is one of the only ways we have to measure how many users we really have.

You can check the code we use to store your anonyomus stats at the ansistrano.com repo and anyway, if you are not comfortable with this, you will always be able to disable this extra step by setting ansistrano_allow_anonymous_stats to false in your playbooks.

Who is using Ansistrano?

Is Ansistrano ready to be used? Here are some companies currently using it:

If you are also using it, please let us know via a PR to this document.

Requirements

In order to deploy your apps with Ansistrano, you will need:

Ansible in your deployer machine

Installation

Ansistrano is an Ansible role distributed globally using Ansible Galaxy. In order to install Ansistrano role you can use the following command.

$ ansible-galaxy install carlosbuenosvinos.ansistrano-deploy carlosbuenosvinos.ansistrano-rollback

Update

If you want to update the role, you need to pass --force parameter when installing. Please, check the following command:

$ ansible-galaxy install --force carlosbuenosvinos.ansistrano-deploy carlosbuenosvinos.ansistrano-rollback

Features

Rollback in seconds (with ansistrano.rollback role)
Customize your deployment with hooks before and after critical steps
Save disk space keeping a maximum fixed releases in your hosts
Choose between SCP (push), RSYNC (push), GIT (pull) or S3 (get) deployment strategies

Main workflow

Ansistrano deploys applications following the Capistrano flow.

Setup phase: Creates the folder structure to hold your releases
Code update phase: Puts the new release into your hosts
Symlink phase: After deploying the new release into your hosts, this step changes the current softlink to new the release
Cleanup phase: Removes any old version based in the ansistrano_keep_releases parameter (see "Role Variables")

Role Variables

- vars:
  ansistrano_deploy_from: "{{ playbook_dir }}" # Where my local project is (relative or absolute path)
  ansistrano_deploy_to: "/var/www/my-app" # Base path to deploy to.
  ansistrano_version_dir: "releases" # Releases folder name
  ansistrano_current_dir: "current" # Softlink name. You should rarely changed it.
  ansistrano_shared_paths: [] # Shared paths to symlink to release dir
  ansistrano_keep_releases: 0 # Releases to keep after a new deployment. See "Pruning old releases".
  ansistrano_deploy_via: "rsync" # Method used to deliver the code to the server. Options are copy, rsync, git or s3
  ansistrano_allow_anonymous_stats: yes

  # Variables used in the rsync deployment strategy
  ansistrano_rsync_extra_params: "" # Extra parameters to use when deploying with rsync in a single string. Although Ansible allows an array this can cause problems if we try to add multiple --include args as it was reported in https://github.com/ansistrano/deploy/commit/e98942dc969d4e620313f00f003a7ea2eab67e86
  ansistrano_rsync_set_remote_user: yes # See [ansible synchronize module](http://docs.ansible.com/ansible/synchronize_module.html). Options are yes, no.

  # Variables used in the Git deployment strategy
  ansistrano_git_repo: [email protected]:USERNAME/REPO.git # Location of the git repository
  ansistrano_git_branch: master # What version of the repository to check out. This can be the full 40-character SHA-1 hash, the literal string HEAD, a branch name, or a tag name
  ansistrano_git_identity_key_path: "" # If specified this file is copied over and used as the identity key for the git commands, path is relative to the playbook in which it is used

  # Variables used in the download deployment strategy
  ansistrano_get_url: https://github.com/someproject/somearchive.tar.gz

  # Variables used in the S3 deployment strategy
  ansistrano_s3_bucket: s3bucket
  ansistrano_s3_object: s3object.tgz
  ansistrano_s3_region: eu-west-1
  # Optional variables, omitted by default
  ansistrano_s3_aws_access_key: YOUR_AWS_ACCESS_KEY
  ansistrano_s3_aws_secret_key: YOUR_AWS_SECRET_KEY

  # Hooks: custom tasks if you need them
  ansistrano_before_setup_tasks_file: "{{ playbook_dir }}/<your-deployment-config>/my-before-setup-tasks.yml"
  ansistrano_after_setup_tasks_file: "{{ playbook_dir }}/<your-deployment-config>/my-after-setup-tasks.yml"
  ansistrano_before_update_code_tasks_file: "{{ playbook_dir }}/<your-deployment-config>/my-before-update-code-tasks.yml"
  ansistrano_after_update_code_tasks_file: "{{ playbook_dir }}/<your-deployment-config>/my-after-update-code-tasks.yml"
  ansistrano_before_symlink_shared_tasks_file: "{{ playbook_dir }}/<your-deployment-config>/my-before-symlink-shared-tasks.yml"
  ansistrano_after_symlink_shared_tasks_file: "{{ playbook_dir }}/<your-deployment-config>/my-after-symlink-shared-tasks.yml"
  ansistrano_before_symlink_tasks_file: "{{ playbook_dir }}/<your-deployment-config>/my-before-symlink-tasks.yml"
  ansistrano_after_symlink_tasks_file: "{{ playbook_dir }}/<your-deployment-config>/my-after-symlink-tasks.yml"
  ansistrano_before_cleanup_tasks_file: "{{ playbook_dir }}/<your-deployment-config>/my-before-cleanup-tasks.yml"
  ansistrano_after_cleanup_tasks_file: "{{ playbook_dir }}/<your-deployment-config>/my-after-cleanup-tasks.yml"

{{ playbook_dir }} is an Ansible variable that holds the path to the current playbook.

Deploying

In order to deploy with Ansistrano, you need to perform some steps:

Create a new hosts file. Check ansible inventory documentation if you need help. This file will identify all the hosts where to deploy to. For multistage environments check Multistage environments.
Create a new playbook for deploying your app, for example, deploy.yml
Set up role variables (see Role Variables)
Include the carlosbuenosvinos.ansistrano-deploy role as part of a play
Run the deployment playbook

ansible-playbook -i hosts deploy.yml

If everything has been set up properly, this command will create the following approximate directory structure on your server. Check how the hosts folder structure would look like after one, two and three deployments.

-- /var/www/my-app.com
|-- current -> /var/www/my-app.com/releases/20100509145325
|-- releases
|   |-- 20100509145325
|-- shared

-- /var/www/my-app.com
|-- current -> /var/www/my-app.com/releases/20100509150741
|-- releases
|   |-- 20100509150741
|   |-- 20100509145325
|-- shared

-- /var/www/my-app.com
|-- current -> /var/www/my-app.com/releases/20100512131539
|-- releases
|   |-- 20100512131539
|   |-- 20100509150741
|   |-- 20100509145325
|-- shared

Serial deployments

To prevent different timestamps when deploying to several servers using the serial option, you should set the ansistrano_release_version variable.

ansible-playbook -i hosts -e "ansistrano_release_version=`date -u +%Y%m%d%H%M%SZ`" deploy.yml

Rolling back

In order to rollback with Ansistrano, you need to set up the deployment and run the rollback playbook.

ansible-playbook -i hosts rollback.yml

If you try to rollback with zero or one releases deployed, an error will be raised and no actions performed.

Variables you can tune in rollback role are less than in deploy one:

- vars:
  ansistrano_deploy_to: "/var/www/my-app" # Base path to deploy to.
  ansistrano_version_dir: "releases" # Releases folder name
  ansistrano_current_dir: "current" # Softlink name. You should rarely changed it.

  # Hooks: custom tasks if you need them
  ansistrano_before_symlink_tasks_file: "{{ playbook_dir }}/<your-deployment-config>/my-before-symlink-tasks.yml"
  ansistrano_after_symlink_tasks_file: "{{ playbook_dir }}/<your-deployment-config>/my-after-symlink-tasks.yml"
  ansistrano_before_cleanup_tasks_file: "{{ playbook_dir }}/<your-deployment-config>/my-before-cleanup-tasks.yml"
  ansistrano_after_cleanup_tasks_file: "{{ playbook_dir }}/<your-deployment-config>/my-after-cleanup-tasks.yml"

Multistage environment (devel, preprod, prod, etc.)

If you want to deploy to different environments such as devel, preprod and prod, it's recommended to create different hosts files. When done, you can specify a different host file when running the deployment playbook using the -i parameter. On every host file, you can specify different users, password, connection parameters, etc.

ansible-playbook -i hosts_devel deploy.yml

ansible-playbook -i hosts_preprod deploy.yml

ansible-playbook -i hosts_prod deploy.yml

Hooks: Custom tasks

You will typically need to reload your webserver after the Symlink step, or download your dependencies before Code update or even do it in production before the Symlink. So, in order to perform your custom tasks you have some hooks that Ansistrano will execute before and after each of the main 3 steps. This is the main benefit against other similar deployment roles.

-- /my-local-machine/my-app.com
|-- hosts
|-- deploy.yml
|-- my-custom-tasks
|   |-- before-code-update.yml
|   |-- after-code-update.yml
|   |-- before-symlink.yml
|   |-- after-symlink.yml
|   |-- before-cleanup.yml
|   |-- after-cleanup.yml

For example, in order to restart apache after Symlink step, we'll add in the after-symlink.yml

- name: Restart Apache
  service: name=httpd state=reloaded

Q: Where would you add sending email notification after a deployment?
Q: (for PHP and Symfony developers) Where would you clean the cache?

You can specify a custom tasks file for before and after every step using ansistrano_before_*_tasks_file and ansistrano_after_*_tasks_file role variables. See "Role Variables" for more information.

Variables in custom tasks

When writing your custom tasks files you may need some variables that Ansistrano makes available to you:

{{ ansistrano_release_path.stdout }}: Path to current deployment release (probably the one you are going to use the most)
{{ ansistrano_releases_path.stdout }}: Path to releases folder
{{ ansistrano_shared_path.stdout }}: Path to shared folder (where common releases assets can be stored)
{{ ansistrano_release_version }}: Relative directory name for the release (by default equals to the current timestamp in UTC timezone)

Pruning old releases

In continuous delivery environments, you will possibly have a high number of releases in production. Maybe you have tons of space and you don't mind, but it's common practice to keep just a custom number of releases.

After the deployment, if you want to remove old releases just set the ansistrano_keep_releases variable to the total number of releases you want to keep.

Let's see three deployments with an ansistrano_keep_releases: 2 configuration:

-- /var/www/my-app.com
|-- current -> /var/www/my-app.com/releases/20100509145325
|-- releases
|   |-- 20100509145325
|-- shared

-- /var/www/my-app.com
|-- current -> /var/www/my-app.com/releases/20100509150741
|-- releases
|   |-- 20100509150741
|   |-- 20100509145325
|-- shared

-- /var/www/my-app.com
|-- current -> /var/www/my-app.com/releases/20100512131539
|-- releases
|   |-- 20100512131539
|   |-- 20100509150741
|-- shared

See how the release 20100509145325 has been removed.

Example Playbook

In the folder, example you can check an example project that shows how to deploy with Ansistrano. In order to run it, you should:

$ cd example
$ ansible-playbook -i hosts deploy.yml

Sample projects

We have added Ansistrano support for other projects we are working on.

LastWishes: Domain-Driven Design PHP Sample App: https://github.com/dddinphp/last-wishes

As an example, see the execution log of the LastWishes deployment:

PLAY [Deploy last wishes app to my server] ************************************

GATHERING FACTS ***************************************************************
ok: [quepimquepam.com]

TASK: [carlosbuenosvinos.ansistrano-deploy | Ensure deployment base path exists] ***
ok: [quepimquepam.com]

TASK: [carlosbuenosvinos.ansistrano-deploy | Ensure releases folder exists] ***
ok: [quepimquepam.com]

TASK: [carlosbuenosvinos.ansistrano-deploy | Ensure shared elements folder exists] ***
ok: [quepimquepam.com]

TASK: [carlosbuenosvinos.ansistrano-deploy | Get release timestamp] ***********
changed: [quepimquepam.com]

TASK: [carlosbuenosvinos.ansistrano-deploy | Get release path] ****************
changed: [quepimquepam.com]

TASK: [carlosbuenosvinos.ansistrano-deploy | Get releases path] ***************
changed: [quepimquepam.com]

TASK: [carlosbuenosvinos.ansistrano-deploy | Get shared path (in rsync case)] ***
changed: [quepimquepam.com]

TASK: [carlosbuenosvinos.ansistrano-deploy | Rsync application files to remote shared copy (in rsync case)] ***
changed: [quepimquepam.com -> 127.0.0.1]

TASK: [carlosbuenosvinos.ansistrano-deploy | Deploy existing code to servers] ***
changed: [quepimquepam.com]

TASK: [carlosbuenosvinos.ansistrano-deploy | Deploy existing code to remote servers] ***
skipping: [quepimquepam.com]

TASK: [carlosbuenosvinos.ansistrano-deploy | Update remote repository] ********
skipping: [quepimquepam.com]

TASK: [carlosbuenosvinos.ansistrano-deploy | Export a copy of the repo] *******
skipping: [quepimquepam.com]

TASK: [carlosbuenosvinos.ansistrano-deploy | Deploy code from to servers] *****
skipping: [quepimquepam.com]

TASK: [carlosbuenosvinos.ansistrano-deploy | Copy release version into REVISION file] ***
changed: [quepimquepam.com]

TASK: [carlosbuenosvinos.ansistrano-deploy | Touches up the release code] *****
changed: [quepimquepam.com]

TASK: [carlosbuenosvinos.ansistrano-deploy | Change softlink to new release] ***
changed: [quepimquepam.com]

TASK: [carlosbuenosvinos.ansistrano-deploy | Reload Apache] *******************
changed: [quepimquepam.com]

TASK: [carlosbuenosvinos.ansistrano-deploy | Clean up releases] ***************
skipping: [quepimquepam.com]

PLAY RECAP ********************************************************************
quepimquepam.com           : ok=14   changed=10   unreachable=0    failed=0

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