COMP1531

Continuous Integration

Presented by Atlassian

In this lecture

What is Continuous Integration?
Building Continuous Integration pipelines

What is it?

Continuous Integration is...

Tools (pipelines)?
Testing?
A process?
Or all of the above?

Continuous Integration

Continuous integration (CI) is the practice of automating the integration of code changes from multiple contributors into a single software project. It’s a primary DevOps best practice, allowing developers to frequently merge code changes into a central repository where builds and tests then run. Automated tools are used to assert the new code’s correctness before integration.

- Atlassian

Let's build a Continuous Integration pipeline in GitLab.

image: comp1531/basic:latest
cache:
	paths:
		- node_modules

stages:
	- checks

sanity:
	stage: checks
	script:
		- echo 'Hello!'

Continuous Integration

DevOps

"Traditional" Software Development

DevOps & Continuous Integration

DevOps

DevOps: The consolidation of "development" and "operations"
Continuous Integration forms one part of the DevOps process

DevOps is a set of practices, tools, and a cultural philosophy that automate and integrate the processes between software development and IT teams. It emphasizes team empowerment, cross-team communication and collaboration, and technology automation.

- Atlassian

DevOps

Why Continuous Integration?

Answer: Risk
Automates layers of quality checks (testing, type checking, linting) on code
Ensures that master/main remains a "safe source of truth"
Provides quality assurance
"But miss, it works on my computer!" - CI is run in a standardised environment
Minimises risk by continuously integrating small changes, rather than making lots of changes at once

Minimising Risk with CI

Minimises risk by continuously integrating small changes, rather than making lots of changes at once
Generally, the more lines changed, the greater the risk
- More accurately: The more areas of the code that your change impacts, the greater the risk (e.g. Crowdstrike)
Nick's advice for merge requests/pull requests:
- Keep them as small as possible - if in doubt, split it up