Skip to content

Latest commit

 

History

History
111 lines (89 loc) · 3.58 KB

02_44-set-up-git-pulls-from-mock-envs.md

File metadata and controls

111 lines (89 loc) · 3.58 KB

Configuring CI/CD pipelines

Continuous Delivery

Deploy via Git

Now, instead of pushing changes to the system, let's build a distributed system; where runners push successfully tested changes to special Git branches; and environments pulls changes from its respective Git.

We'll just use the Prod environment. Let's set up the deploy-to-prod job to push to the "prod" branch in Git; and let's set up the Prod environment to pull from the "prod" branch (while development continues on the "master" branch).

Addition of feature 'b' triggers CI/CD 
            \

         a---b---c---d  branch 'master'
             |
             v
    branch 'prod' 

CI/CD pushes 'b' code to 'prod' branch

Configuring CI/CD pipelines

Continuous Delivery

Deploy via Git

Let's initialize the "prod" branch and ensure Prod can pull from it.

Initialize "prod" branch (off "master"):

sudo su - gitlab-runner
GIT_SSH_COMMAND="ssh -i ~gitlab-runner/.ssh/push_to_git" git clone [email protected]:root/www.git 
cd www
git checkout -b prod
GIT_SSH_COMMAND="ssh -i ~gitlab-runner/.ssh/push_to_git" git push origin prod   
cd ..
rm -rf www
exit

Configuring CI/CD pipelines

Continuous Delivery

Deploy via Git

Check that Prod can pull from "prod" branch:

sudo su - root -c "GIT_SSH_COMMAND='ssh -i ~/.ssh/pull_from_git' git archive [email protected]:root/www.git prod | tar -t"

You should see the list of file in the "prod" branch:

ubuntu@ip-172-31-23-12:~$ sudo su - root -c "GIT_SSH_COMMAND='ssh -i ~root/.ssh/pull_from_git' git archive [email protected]:root/www.git prod | tar -t"
.gitlab-ci.yml
Hello.php
HelloTest.php
README.md
index.php
ubuntu@ip-172-31-23-12:~$

Configuring CI/CD pipelines

Continuous Delivery

Deploy via Git

Go ahead and install the files once manually, just to make sure it all works:

sudo su - root -c 'GIT_SSH_COMMAND="ssh -i ~root/.ssh/pull_from_git" git archive [email protected]:root/www.git prod | tar -xv -C /var/www/prod-html --exclude=.gitlab-ci.yml'

Example output:

ubuntu@ip-172-31-23-12:~$ sudo su - root -c 'GIT_SSH_COMMAND="ssh -i ~root/.ssh/pull_from_git" git archive [email protected]:root/www.git prod | tar -xv -C /var/www/prod-html --exclude=.gitlab-ci.yml'
Hello.php
HelloTest.php
README.md
index.php
ubuntu@ip-172-31-23-12:~$

Configuring CI/CD pipelines

Continuous Delivery

Deploy via Git

Set up Production environment to track the "prod" branch with a root cron job:

echo '* * * * * root GIT_SSH_COMMAND="ssh -i ~root/.ssh/pull_from_git" git archive [email protected]:root/www.git prod 2>/dev/null| tar -xv -C /var/www/prod-html --exclude=.gitlab-ci.yml 2>/dev/null' | sudo tee -a /etc/crontab

Configuring CI/CD pipelines

Continuous Delivery

Side notes

  1. You may want to look into a tool like dpl which can deploy to a wide variety of service providers.

  2. The way CFEngine's contrib/masterfiles-stage.sh handles Git is, it stages the changes in a side directory, validates them, and then does the tablecloth pull trick where it swaps out the old content and swaps in the new (with two back-to-back calls to mv) so you never get half old and half new.

  3. Next best thing after that is instantiating a new environment with the new code.