flux2 VS atlantis

Given the team had already adopted GitOps and were familiar with deployments powered by Helm Releases and Flux, we wanted to move the provisioning of the infrastructure to be part of the same process of creating the service and its continuous deployment.

Your GitHub action can trigger a helm chart, or series thereof, or other infra tools. Declarative specifications, triggered procedurally with the context of the branch’s latest build. We use this pattern quite extensively for preview app workflows.

As of a year ago this is possible in a fully declarative way with Flux 2, but there’s a lot more moving parts and security footguns - and the idea that the maintenance of this project has lost one of its primary sponsors is worrying at best.

https://github.com/fluxcd/flux2/discussions/831

https://blog.kluctl.io/introducing-the-template-controller-a...

FluxCD - FluxCD is another popular GitOps tool that allows developers to use a Git repository as the sole source of configuration. Flux automatically ensures that the state of the Kubernetes cluster is synchronized with the configuration in the Git repository. It supports automatic updates, meaning Flux can monitor Docker image repositories for new images and push updates to the cluster.

#!/bin/bash aws eks update-kubeconfig --name $CLUSTER_NAME --region $AWS_REGION flux_installed=$(kubectl api-resources | grep flux) if [ -z "$flux_installed" ]; then echo "flux is not installed" curl -s https://fluxcd.io/install.sh | sudo bash flux bootstrap github \ --owner=$GH_USER_NAME \ --repository=$FLUX_REPO_NAME \ --path="clusters/$ENVIRONMENT/$CLUSTER_NAME/bootstrap" \ --branch=main \ --personal else echo "flux is installed" fi

Flux CD enables continuous deployment to Kubernetes through GitOps by syncing Git repositories with Kubernetes clusters. Flux CD enables GitOps for Kubernetes through source control integration. It manages Kubernetes manifests as code and syncs git repo changes to clusters. Flux automates checks, deployments, and updates within clusters.

FluxCD is a GitOps tool developed by Weaveworks that allows you to implement continuous and progressive delivery of your applications on Kubernetes. It is a CNCF graduated project that offers a set of controllers to monitor Git repositories and reconciles the cluster's actual state with the desired state defined by manifests committed in the repo.

From here, we can explore other developments and tutorials on Kubernetes, such as o11y or observability (PLG, ELK, ELF, TICK, Jaeger, Pyroscope), service mesh (Linkerd, Istio, NSM, Consul Connect, Cillium), and progressive delivery (ArgoCD, FluxCD, Spinnaker).

Instead, we will create a single long-lived cluster, and deploy our application in different namespaces. There are a bunch of ways to do that - see ArgoCD, Flux, custom internal tooling, or other solutions (we use our own product). That way, we:

One is to make sure configurations in both clusters is same. And for that there are many tools like fluxcd or projectsveltos

None of these are a replacement of Terraform Cloud (recently rebranded to HCP Terraform). For example, when you create a PR, it could affect multiple workspaces. The new experimental version of TFC/TFE (I refuse to call it HCP!) implements Stacks, which is something like a workflow, and links one workspace output to other workspace inputs. None of the open-source solutions, including the paid Digger [0], support this - only the paid one, such as Spacelift [1] (which is the closest to TFC if you ask me). Having a monorepo of Terraform is a common design pattern, so, if I change an embedded module, it could trigger changes it many workspaces. As far as I know, Atlantis [2] can't really help in this case.

By the way, the reason I singled-out Spacelift is due to its quality, and the great Terraform provider it has. Scalr [3], for example, has a really low-quality Terraform provider. I extensively use the hashicorp/tfe provider to manage TFC itself.

[0]: https://digger.dev/

[1]: https://spacelift.io/

[2]: https://www.runatlantis.io/

[3]: https://www.scalr.com/

Atlantis is a pull request automation tool that works well with plain Terraform right away. But what if we're already using Terramate to generate Terraform code?

Atlantis automates reviewing and deploying Terraform via pull requests, streamlining collaboration and ensuring consistency across Terraform deployments.

For example, Atlantisgo for Terraform, Zapier’s Kubechecks for Argo CD, Quizlet’s GitHub action all do something similar to this. But a generic, extensible tool for IaC providers doesn’t seem to exist. Additionally, many of them require exposing your Kubernetes cluster or other infrastructure to third-party access, webhooks, etc.

Our first attempt was to introduce other engineering teams to Terraform - the Platform team was already using it extensively with Terragrunt, and using Atlantis to automate plan and apply operations in a Git flow to ensure infrastructure was consistent. We'd written modules, with documentation, and an engineer would simply need to raise a PR to use the module and provide the right values, and Atlantis (once the PR was approved by Platform) would go ahead and set it up for them.

Alternatively, you can look at solutions like Atlantis or spacelift.

Atlantis: https://www.runatlantis.io/

Looking at the commits at https://github.com/runatlantis/atlantis, it looks like 1.6.5. Am I right?

We use Atlantis [0] for CI/CD automation of Terraform pull requests to a centralized repository. It's pretty good too, especially for a self-hosted solution. I can't see how Terraform Cloud's costs would be justifiable for us without a custom contract.

[0] https://www.runatlantis.io/