---
title: Deployment and CI/CD Process
---

# Deployment and CI/CD Process

## Overview

DEV relies on GitHub and Travis to deploy continuously to Heroku. If a Pull
Request is merged with a `[deploy]` in its title, it will be automatically
deployed to production once the build steps complete successfully. The process
currently takes about 20 minutes to complete and will need a few additional
minutes before the change goes live.

## Travis steps

The following steps can be explored in our
[.travis.yml](https://github.com/thepracticaldev/dev.to/blob/master/.travis.yml)
and [Procfile](https://github.com/thepracticaldev/dev.to/blob/master/Procfile).
Some of the steps will be parallelized in the future:

1. Travis runs the test portion of Rails code.
1. Travis runs the test portion of Preact code.
1. CodeClimate-test-reporter combines the test result and coverage from Ruby and
   JavaScript code then uploads it to our CodeClimate dashboard.
1. `bundle-audit` checks for any known vulnerability.
1. Travis builds Storybook to ensure its integrity.
1. Travis deploys code to Heroku.
   - Heroku runs the database migrations and Elasticsearch updates before
     deployment.
1. Travis notifies the team that the process completed.

## Deploying to Heroku

We use Heroku's
[Release Phase](https://devcenter.heroku.com/articles/release-phase) feature.
Upon deploy, the app installs dependencies, bundles assets, and gets the app
ready for launch. However, before it launches and releases the app Heroku runs a
release script on a one-off dyno. If that release script/step succeeds the new
app is released on all of the dynos. If that release script/step fails then the
deploy is halted and we are notified.

The name of the script we use is `release-tasks.sh` and its in our root
directory. During this release step we do a few checks.

1. We first check the DEPLOY_STATUS environment variable. In the event that we
   want to prevent deploys, for example after a rollback, we will set
   DEPLOY_STATUS to "blocked". This will cause the release script to exit with a
   code of 1 which will halt the deploy. This ensures that we don't accidentally
   push out code while we are waiting for a fix or running other tasks.
2. We run any outstanding migrations. This ensures that a migration finishes
   successfully before the code that uses it goes live.
3. We run any data update scripts that need to be run. A data update script is
   one that allows us to update data in the background separate from a
   migration. For example, if we add a new field to Elasticsearch and need to
   reindex all of our documents we would use a data update script.
4. We update Elasticsearch. Elasticsearch contains indexes which have mappings.
   Mappings are similar to database schema. The same way we run a migration to
   update our database we have to run a setup task to update any Elasticsearch
   mappings.
5. Following updating all of our datastores we use the Rails runner to output a
   simple string. Executing a Rails runner command ensures that we can boot up
   the entire app successfully before it is deployed. We deploy asynchronously,
   so the website is running the new code a few minutes after deploy. A new
   instance of Heroku Rails console will immediately run a new code.

![](https://devcenter0.assets.heroku.com/article-images/1494371187-release-phase-diagram-3.png)