oliverdavies.uk/source/_posts/automating-sculpin-jenkins.md

---
title: Automating Sculpin Builds with Jenkins CI
date: 2015-07-21
excerpt: How to use Jenkins to automate building Sculpin websites.
tags:
  - jenkins
  - sculpin
---

As part of re-building this site with [Sculpin](http://sculpin.io), I wanted to
automate the deployments, as in I wouldn't need to run a script like
[publish.sh](https://raw.githubusercontent.com/sculpin/sculpin-blog-skeleton/master/publish.sh)
locally and have that deploy my code onto my server. Not only did that mean that
my local workflow was simpler (update, commit and push, rather than update,
commit, push and deploy), but if I wanted to make a quick edit or hotfix, I
could log into GitHub or Bitbucket (wherever I decided to host the source code)
from any computer or my phone, make the change and have it deployed for me.

I'd started using [Jenkins CI](http://jenkins-ci.org) during my time at the
Drupal Association, and had since built my own Jenkins server to handle
deployments of Drupal websites, so that was the logical choice to use.

## Installing Jenkins and Sculpin

If you don’t already have Jenkins installed and configured, I'd suggest using
[Jeff Geerling](http://jeffgeerling.com/) (aka geerlingguy)'s
[Ansible role for Jenkins CI](https://galaxy.ansible.com/list#/roles/440).

I've also released an
[Ansible role for Sculpin](https://galaxy.ansible.com/list#/roles/4063) that
installs the executable so that the Jenkins server can run Sculpin commands.

## Triggering a Build from a Git Commit

I created a new Jenkins item for this task, and restricted where it could be run
to `master` (i.e. the Jenkins server rather than any of the nodes).

### Polling from Git

I entered the url to the
[GitHub repo](https://github.com/opdavies/oliverdavies.uk) into the **Source
Code Management** section (the Git option _may_ have been added by the
[Git plugin](https://wiki.jenkins-ci.org/display/JENKINS/Git+Plugin) that I have
installed).

As we don’t need any write access back to the repo, using the HTTP URL rather
than the SSH one was fine, and I didn’t need to provide any additional
credentials.

Also, as I knew that I’d be working a lot with feature branches, I entered
`*/master` as the only branch to build. This meant that pushing changes or
making edits on any other branches would not trigger a build.

![Defining the Git repository in Jenkins](/images/blog/oliverdavies-uk-jenkins-git-repo.png)

I also checked the **Poll SCM** option so that Jenkins would be routinely
checking for updated code. This essentially uses the same syntax as cron,
specifying minutes, hours etc. I entered `* * * * *` so that Jenkins would poll
each minute, knowing that I could make this less frequent if needed.

This now that Jenkins would be checking for any updates to the repo each minute,
and could execute tasks if needed.

### Building and Deploying

Within the **Builds** section of the item, I added an _Execute Shell_ step,
where I could enter a command to execute. Here, I pasted a modified version of
the original publish.sh script.

```bash
#!/bin/bash

set -uex

sculpin generate --env=prod --quiet
if [ $? -ne 0 ]; then echo "Could not generate the site"; exit 1; fi

rsync -avze 'ssh' --delete output_prod/ prodwww2:/var/www/html/oliverdavies.uk/htdocs
if [ $? -ne 0 ]; then echo "Could not publish the site"; exit 1; fi
```

This essentially is the same as the original file, in that Sculpin generates the
site, and uses rsync to deploy it somewhere else. In my case, `prodwww2` is a
Jenkins node (this alias is configured in `/var/lib/jenkins/.ssh/config`), and
`/var/www/html/oliverdavies.uk/htdocs` is the directory from where my site is
served.

## Building Periodically

There is some dynamic content on my site, specifically on the Talks page. Each
talk has a date assigned to it, and within the Twig template, the talk is
positoned within upcoming or previous talks based on whether this date is less
or greater than the time of the build.

The YAML front matter:

```yaml
---
...
talks:
    - title: Test Drive Twig with Sculpin
            location: DrupalCamp North
---
```

The Twig layout:

```twig
{% verbatim %}
{% for talk in talks|reverse if talk.date >= now %}
    {# Upcoming talks #}
{% endfor %}

{% for talk in talks if talk.date < now %}
    {# Previous talks #}
{% endfor %}
{% endverbatim %}
```

I also didn’t want to have to push an empty commit or manually trigger a job in
Jenkins after doing a talk in order for it to be positioned in the correct place
on the page, so I also wanted Jenkins to schedule a regular build regardless of
whether or not code had been pushed, so ensure that my talks page would be up to
date.

After originally thinking that I'd have to split the build steps into a separate
item and trigger that from a scheduled item, and amend my git commit item
accordingly, I found a **Build periodically** option that I could use within the
same item, leaving it intact and not having to make amends.

I set this to `@daily` (the same `H H * * *` - `H` is a Jenkins thing), so that
the build would be triggered automatically each day without a commit, and deploy
any updates to the site.

![Setting Jenkins to periodically build a new version of the site.](/images/blog/oliverdavies-uk-jenkins-git-timer.png)

## Next Steps

This workflow works great for one site, but as I roll out more Sculpin sites,
I'd like to reduce duplication. I see this mainly as I’ll end up creating a
separate `sculpin_build` item that’s decoupled from the site that it’s building,
and instead passing variables such as environment, server name and docroot path
as parameters in a parameterized build.

I'll probably also take the raw shell script out of Jenkins and save it in a
text file that's stored locally on the server, and execute that via Jenkins.
This means that I’d be able to store this file in a separate Git repository with
my other Jenkins scripts and get the standard advantages of using version
control.

## Update

Since publishing this post, I've added some more items to the original build
script.

### Updating Composer

```bash
if [ -f composer.json ]; then
    /usr/local/bin/composer install
fi
```

Updates project dependencies via
[Composer](https://getcomposer.org/doc/00-intro.md#introduction) if
composer.json exists.

### Updating Sculpin Dependencies

```bash
if [ -f sculpin.json ]; then
  sculpin install
fi
```

Runs `sculpin install` on each build if the sculpin.json file exists, to ensure
that the required custom bundles and dependencies are installed.

### Managing Redirects

```bash
if [ -f scripts/redirects.php ]; then
    /usr/bin/php scripts/redirects.php
fi
```

I've been working on a `redirects.php` script that generates redirects from a
.csv file, after seeing similar things in the
[Pantheon Documentation](https://github.com/pantheon-systems/documentation) and
[That Podcast](https://github.com/thatpodcast/thatpodcast.io) repositories. This
checks if that file exists, and if so, runs it and generates the source file
containing each redirect.