September 2022

This article details my findings when comparing ArgoCD and Flux. As a heavy Flux user at Hopin the motivation behind this assessment was to understand if ArgoCD could replace Flux, thus I’m going to set Flux as the baseline.

First time I heard of GitOps I shrugged and thought to myself: What’s the big deal, my infra is in code and I already use github actions to deploy. I’m ahead of my time. 🤡

Like any self-centered thought it lacked context and a bit of research. Back then I wasn’t using Kubernetes, not even containers. Puppet or Ansible would take care of maintaining the state of my VM’s. It worked and we were happy to have IaC, CaC and automation.

However according to the industry: CaC + automation ≠ GitOps

Flux v2

When it comes to GitOps, the first thing that usually comes up is Kubernetes and operators. In 2017 a blogpost coined the term GitOps. It also named the first GitOps operator: Flux. Eventually this was completely rewritten as Flux v2.

• Although GitOps is not exclusively applicable to Kubernetes, the core principles align well with the underlying design principles of Kubernetes, which is why GitOps and Kubernetes work well together. Today the most popular GitOps tools are Flux and ArgoCD, both Kubernetes operators.
• The GitOps operator is used to run the reconciliation loop, which syncs the target state declared in Git with the actual state of the cluster. In the event of differences, the operator takes care of convergence to the target state.

This said Flux came first 🥇 and that’s possible the reason your company uses it.

How to install

Concepts

ArgoCD

ArgoCD offers an alternative to Flux. It belongs to the Argo project, which just like Flux was accepted to CNCF incubator phase. It was created in 2018 and since then managed to get 10k stars in github while Flux v2 has 4k 🥵 It’s not a popularity contest but a quick look at last month commits shows a bigger activity in ArgoCD.

• ArgoCD has a rich UI and was built with it in mind, so it’s been there from the beginning. It also integrates with ArgoCD’s access control policies and has the ability to show a “read-only” dashboard.
  • To be honest the UI is ArgoCD’s biggest trade secret. Several articles will tell you in detail where both tools match and diverge, but in the end ask anyone using ArgoCD and the UI is top of their minds. And it’s a fair reason, thanks to that, features like SSO and dashboards are available out of the shelf.