Docker e git lab

Docker & GitLabDocker & GitLab as a Continuous Integration platform

GPad

Born to be a developer with an interest in “system admin”

I develop using many languages like C++, C#, js and ruby. I have recently fallen in love with functional programming, especially with elixir, erlang, clojure and haskell.

CTO & founder of coders51

We develop web and mobile solutions for the entire galaxy

We don’t develop web sites

At least not simple ones ...

Every time there is something new and interesting, we want to be there!!

Technologies

Continuous Integration https://en.wikipedia.org/wiki/Continuous_integration:

Continuous integration (CI) is the practice, in software engineering, of merging all developer working copies to a shared mainline several times a day. It was first named and proposed by Grady Booch in his 1991 method, although Booch did not advocate integrating several times a day. It was adopted as part of extreme programming (XP), which did advocate integrating more than once per day, perhaps as many as tens of times per day.

Continuous Integration http://www.martinfowler.com/articles/continuousIntegration.html:

Continuous Integration is a software development practice where members of a team integrate their work frequently, usually each person integrates at least daily - leading to multiple integrations per day. Each integration is verified by an automated build (including test) to detect integration errors as quickly as possible. Many teams find that ….

Install Install InstallEach software should be installed on a CI computer

Each software with its own dependencies

Each software has different dependencies

Each software has different dependencies with different versions

This is a mess ...

How we used to do it ...

It works on my computer ...One test fails on the CI computer, but not on the developer’s computer

The CI environment is different from the production environment

The CI environment is different from the development environment

Who cleans up this mess ?!?After running the tests we have some dirty data

Dirty data in the database

Dirty data in the file system

Some dirty states on the external services

GitLab

GitLab as CI

GitLab as CI

GitLab as CI

GitLab as CI

Why Docker?!?If we use Docker:

- We can create an isolated environment

- It’s not necessary to clean data after the tests

- It’s “simple” to put together all the necessary external services

- It’s easy to replicate on different computers

Install becomes DeclareIt’s not necessary to install all software on the CI computer

We can “declare” external dependencies

In .gitlab-ci.yml we can declare everything regarding the software under test:

- which images we require

- which services we depend on

- which scripts we want to execute

Install becomes Declare

Install becomes Declare

Install becomes Declare

Install becomes Declare

Install becomes Declare

Install becomes Declare

Install becomes Declare

Install becomes Declare

Install becomes Declare

Auto-cleaning system ...The images are stored in cache on the CI server

At every restart the state of the container is known

It’s simple to avoid a corrupted situation

If the test fails we don’t have any “garbage data” left over

Easily replicableLocal:

Easily replicable ...GitLab:

Easily replicable ...GitLab:

Easily replicable ...Run mongo:

sudo docker run --name mongo-dockerops -d mongo

Run node:

sudo docker run -it --link mongo-dockerops:mongo -v `pwd`:/opt/app node:0.12 /bin/bash

root@9b71e87dfd1c:/# grunt test

Pros & ConsPROS

No need to install all software on the CI computer

The environment is always clean at every restart

The CI environment can be replicated on every computer

CONS

It’s slow when there are a lot of dependencies to download

We need to manage new technologies (Docker)

Evolution ?!?Start to use Docker on development machine with Compose

Evolution ?!?Start to use Docker in production ...

Thank you!!!!

Q&A!!!