Categories
microservices patterns

GitOps workflow

I have been using GitOps in my last project and I like the way it changed my workflow. It had to change as in the world of microservices old ways have to go. It is not a post if this is good or bad, I may write one someday. This post is about GitOps, if you do not know what GitOps is read here. TLDR version: in practice, each commit deploys a new version of a service to one’s cluster.

Going back to the subject of the workflow. I’ll focus on the microservices workflow as here in my opinion GitOps is extremely useful. One of the main pain points of microservices architecture is deployment. When deployments are mentioned you instinctively think about deploying the application. It may be difficult but it is not as difficult as creating developer environments and QA environments.

Here comes GitOps. When applied to your project you immediately get new service per each commit. This applies to each service you have. Having this at your disposal you can set up your application in numerous combinations of versions. You can also easily replace one of the services in your stack. Sounds good but nothing beats a demo, so here we go.

Demo

Let’s say I have a task of verifying if our changes to one of the microservices are correct. I’m using Rio to manage my Kubernetes cluster as it makes things smoother. Change in one service affects another service, and I have to verify it using UI. This adds up to 3 services deployed in one namespace and configured so they talk to each other. After I add commit in the service repository there is a namespace already created on a cluster. Each commit creates a new version of the service.

% rio -n bugfix ps -q
bugfix:app

Now I need to add missing services, and I can do it by branching off from master. The name of the branch must match in all services involved.

% cd other_services && git checkout -b bugfix 
% git push

After pushing the changes Rio adds them to the same namespace.

% rio -n bugfix ps -q
bugfix:app
bugifx:web
bugfix:other_app

One thing left is to wire them up so services talk to each other. As I’m using recommendations from https://12factor.net/config so it is dead easy, and I can use Rio to do it. Edit command allows me to modify the environment variables of each service.

% rio -n bugfix edit web

This opens up your favourite text editor where you can edit the variables and setup where the web app can find other services. You can do the same changes in other services if necessary.

I have wired up services, they are talking to each other and I can proceed with my work. This my workflow using GitOps, Rio, and microservices.