gitops-playground

Reproducible infrastructure to showcase GitOps workflows with Kubernetes.
Derived from our experiences in consulting and operating the myCloudogu platform.

We are working on distilling the logic used in the example application pipelines into a reusable library for Jenkins: cloudogu/gitops-build-lib.

If you have any questions, remarks or ideas regarding the gitops-playground, feel free to visit our community.
Or if you want to chat with us about gitops in general, visit us here.

TLDR; You can run a local k8s cluster with the GitOps playground installed with only one command (on Linux)

bash <(curl -s \
  https://raw.githubusercontent.com/cloudogu/gitops-playground/main/scripts/init-cluster.sh) \
  && sleep 2 && docker run --rm -it -v ~/.k3d/kubeconfig-gitops-playground.yaml:/home/.kube/config \
    --net=host \
    ghcr.io/cloudogu/gitops-playground --yes

This command will also print URLs of the applications inside the cluster to get you started.

Table of contents

• What is the GitOps Playground?
• Installation
  • Create Cluster
  • Apply playground
    • Apply via Docker (local cluster)
    • Apply via kubectl (remote cluster)
    • Additional parameters
  • Remove playground
• Applications
  • Credentials
  • Jenkins
  • SCM-Manager
  • ArgoCD UI
  • Demo applications
    • Flux V1
    • Flux V2
    • ArgoCD
• Testing

What is the GitOps Playground?

The GitOps Playground provides an reproducible environment for trying out GitOps. Is consists of Infra As Code and scripts for automatically setting up a Kubernetes Cluster including CI-server (Jenkins), source code management (SCM-Manager) and several GitOps operators (Flux V1, Flux V2, ArgoCD). CI-Server, SCM and operators are pre-configured with a number of demo applications.

The GitOps Playground lowers the barriers for getting your hands on GitOps. No need to read lots of books and operator docs, getting familiar with CLIs, ponder about GitOps Repository folder structures and staging, etc. The GitOps Playground is a pre-configured environment to see GitOps in motion.

Installation

There a several options for running the GitOps playground

• on a local k3d cluster
  NOTE: Currently runs only on linux!
  Running on Windows or Mac is possible in general, but we would need to bind all needed ports to k3d container.
  See our POC. Let us know if this feature is of interest to you.
• on a remote k8s cluster
• each with the option
  • to use an external Jenkins, SCM-Manager and registry (this can be run in production, e.g. with a Cloudogu Ecosystem) or
  • to run everything inside the cluster (for demo only)

The diagrams bellow show an overview of the playground's architecture and three scenarios for running the playground.

Note that running Jenkins inside the cluster is meant for demo purposes only. The third graphic shows our production scenario with the Cloudogu EcoSystem (CES). Here better security and build performance is achieved using ephemeral Jenkins build agents spawned in the cloud.

Demo on local machine	Demo on remote cluster	Production environment with CES

Create Cluster

If you don't have a demo cluster at hand we provide scripts to create either

• a local k3d cluster (see docs or script for more details):

  bash <(curl -s \
    https://raw.githubusercontent.com/cloudogu/gitops-playground/main/scripts/init-cluster.sh)

• a remote k8s cluster on Google Kubernetes Engine (e.g. via Terraform, see our docs),
• or almost any k8s cluster.
  Note that if you want to deploy Jenkins inside the cluster, Docker is required as container runtime.

Apply playground

You can apply the playground to your cluster using our container image ghcr.io/cloudogu/gitops-playground.
On success, the container prints a little intro on how to get started with the GitOps playground.

There are several options for running the container:

• For local k3d cluster, we recommend running the image as a local container via docker
• For remote clusters (e.g. on GKE) you can run the image inside a pod of the target cluster via kubectl.

All options offer the same parameters, see bellow.

Apply via Docker (local cluster)

When connecting to k3d it is easiest to apply the playground via a local container in the host network and pass k3d's kubeconfig.

CLUSTER_NAME=gitops-playground
docker run --rm -it -v ~/.k3d/kubeconfig-${CLUSTER_NAME}.yaml:/home/.kube/config \
  --net=host \
  ghcr.io/cloudogu/gitops-playground # additional parameters go here

Using the host network makes it possible to determine localhost and to use k3d's kubeconfig without altering, as it access the API server via a port bound to localhost.

Apply via kubectl (remote cluster)

For remote clusters it is easiest to apply the playground via kubectl.

# Create a temporary ServiceAccount and authorize via RBAC. This is needed to install CRDs, etc.
kubectl create serviceaccount gitops-playground-job-executer -n default
kubectl create clusterrolebinding gitops-playground-job-executer \
  --clusterrole=cluster-admin \
  --serviceaccount=default:gitops-playground-job-executer

# Then start apply the playground with the following command
# The --remote parameter exposes Jenkins, SCMM and argo on well-known ports for example, 
# so you don't have to remember the individual ports
kubectl run gitops-playground -i --tty --restart=OnFailure \
  --overrides='{ "spec": { "serviceAccount": "gitops-playground-job-executer" } }' \
  --image ghcr.io/cloudogu/gitops-playground \
  -- --yes --remote # additional parameters go here

# If everything succeeded, remove the objects
kubectl delete clusterrolebinding/gitops-playground-job-executer \
  sa/gitops-playground-job-executer pods/gitops-playground -n default  

In general docker run should work here as well. But GKE, for example, uses gcloud and python in their kubeconfig. Running inside the cluster avoids these kinds of issues.

Additional parameters

The following describes more parameters and use cases.

You can get a full list of all options like so:

docker run --rm ghcr.io/cloudogu/gitops-playground --help

Deploy specific GitOps operators only

• --argocd - deploy only argoCD GitOps operator
• --fluxv1 - deploy only Flux v1 GitOps operator
• --fluxv2 - deploy only Flux v2 GitOps operator

Deploy with local Cloudogu Ecosystem

See our Quickstart Guide on how to set up the instance.
Then set the following parameters.

# Note: 
# * In this case --password only sets the argocd admin password (Jenkins and SCMM are external)
# * Insecure is needed, because the local instance will not have a valid cert
--jenkins-url=https://192.168.56.2/jenkins \ 
--scmm-url=https://192.168.56.2/scm \
--jenkins-username=admin \
--jenkins-password=yourpassword \
--scmm-username=admin \
--scmm-password=yourpassword \
--password=yourpassword \
--insecure

Deploy with productive Cloudogu Ecosystem and GCR

Using Google Container Registry (GCR) fits well with our cluster creation example via Terraform on Google Kubernetes Engine (GKE), see our docs.

Note that you can get a free CES demo instance set up with a Kubernetes Cluster as GitOps Playground here.

# Note:
# In this case --password only sets the argocd admin password (Jenkins and SCMM are external) 
--jenkins-url=https://your-ecosystem.cloudogu.net/jenkins \ 
--scmm-url=https://your-ecosystem.cloudogu.net/scm \
--jenkins-username=admin \
--jenkins-password=yourpassword \
--scmm-username=admin \
--scmm-password=yourpassword \
--password=yourpassword \
--registry-url=eu.gcr.io \
--registry-path=yourproject \
--registry-username=_json_key \ 
--registry-password="$( cat account.json | sed 's/"/\\"/g' )" 

Override default images used in the gitops-build-lib

Images used by the gitops-build-lib are set in the gitopsConfig in each Jenkinsfile of an application like that:

def gitopsConfig = [
    ...
    buildImages          : [
            helm: 'ghcr.io/cloudogu/helm:3.5.4-1',
            kubectl: 'lachlanevenson/k8s-kubectl:v1.19.3',
            kubeval: 'ghcr.io/cloudogu/helm:3.5.4-1',
            helmKubeval: 'ghcr.io/cloudogu/helm:3.5.4-1',
            yamllint: 'cytopia/yamllint:1.25-0.7'
    ],...

To override each image in all the applications you can use following parameters:

• --kubectl-image someRegistry/someImage:1.0.0
• --helm-image someRegistry/someImage:1.0.0
• --kubeval-image someRegistry/someImage:1.0.0
• --helmkubeval-image someRegistry/someImage:1.0.0
• --yamllint-image someRegistry/someImage:1.0.0

Remove playground

For k3d, you can just k3d cluster delete gitops-playground.

On remote clusters there is a script inside this repo:

bash <(curl -s \
  https://raw.githubusercontent.com/cloudogu/gitops-playground/main/scripts/destroy.sh) 

Applications

As described above the GitOps playground comes with a number of applications. Some of them can be accessed via web.

• Jenkins
• SCM-Manager
• ArgoCD
• Demo applications for each GitOps operator, each with staging and production instance.

The URLs of the applications depend on the environment the playground is deployed to. The following lists all application and how to find out their respective URLs for a GitOps playground being deployed to local or remote cluster.

For remote clusters you need the external IP, no need to specify the port (everything running on port 80). Basically, you can get the IP address as follows:

kubectl -n "${namespace}" get svc "${serviceName}" \
  --template="{{range .status.loadBalancer.ingress}}{{.ip}}{{end}}"

There is also a convenience script scripts/get-remote-url. The script waits, if externalIP is not present, yet. You could use this conveniently like so:

bash <(curl -s \
  https://raw.githubusercontent.com/cloudogu/gitops-playground/main/scripts/get-remote-url) \
  jenkins default

You can open the application in the browser right away, like so for example:

xdg-open $(bash <(curl -s \
  https://raw.githubusercontent.com/cloudogu/gitops-playground/main/scripts/get-remote-url) \
   jenkins default)

Credentials

If deployed within the cluster Jenkins, SCM-Manager and ArgoCD can be accessed via: admin/admin

Note that you can change (an should for a remote cluster!) the password with apply.sh's --password argument.

Jenkins

Jenkins is available at

• http://localhost:9090 (k3d)
• scripts/get-remote-url jenkins default (remote k8s)

You can enable browser notifications about build results via a button in the lower right corner of Jenkins Web UI.

Note that this only works when using localhost or https://.

External Jenkins

You can set an external jenkins server via the following parameters when applying the playground. See Parameters for examples.

• --jenkins-url,
• --jenkins-username,
• --jenkins-password

Note that the demo applications pipelines will only run on a Jenkins that uses agents that provide a docker host. That is, Jenkins must be able to run e.g. docker ps successfully on the agent.

The user has to have the following privileges:

• install plugins
• set credentials
• create jobs
• restarting

SCM-Manager

SCM-Manager is available at

• http://localhost:9091 (k3d)
• scripts/get-remote-url scmm-scm-manager default (remote k8s)

External SCM-Manager

You can set an external SCM-Manager via the following parameters when applying the playground. See Parameters for examples.

• --scmm-url,
• --scmm-username,
• --scmm-password

The user on the scm has to have privileges to:

• add / edit users
• add / edit permissions
• add / edit repositories
• add / edit proxy
• install plugins

ArgoCD UI

ArgoCD's web UI is available at

• http://localhost:9092 (k3d)
• scripts/get-remote-url argocd-server argocd (remote k8s)

Demo applications

Each GitOps operator comes with a couple of demo applications that allow for experimenting with different GitOps features.

All applications are deployed via separated application and GitOps repos:

• Separation of app repo and GitOps repo
• Infrastructure as Code is maintained in app repo,
• CI Server writes to GitOps repo and creates PullRequests.

The applications implement a simple staging mechanism:

• After a successful Jenkins build, the staging application will be deployed into the cluster by the GitOps operator.
• Deployment of production applications can be triggered by accepting pull requests.

Note that we are working on moving the GitOps-related logic into a gitops-build-lib for Jenkins. See the README there for more options like

• staging,
• resource creation,
• validation (fail early / shift left).

Please note that it might take about a minute after the pull request has been accepted for the GitOps operator to start deploying. Alternatively you can trigger the deployment via the respective GitOps operator's CLI (flux) or UI (argo CD)

Flux V1

PetClinic with plain k8s resources

Jenkinsfile for plain k8s deployment

• Staging:
  • local: localhost:30001
  • remote: scripts/get-remote-url spring-petclinic-plain fluxv1-staging
• Production:
  • local: localhost:30002
  • remote: scripts/get-remote-url spring-petclinic-plain fluxv1-production
• QA (example for a 3rd stage)
  • local: localhost:30003
  • remote: scripts/get-remote-url spring-petclinic-plain fluxv1-qa

PetClinic with helm

Jenkinsfile for helm deployment

• Staging
  • local: localhost:30004
  • remote: scripts/get-remote-url spring-petclinic-helm-springboot fluxv1-staging
• Production
  • local: localhost:30005
  • remote: scripts/get-remote-url spring-petclinic-helm-springboot fluxv1-production

3rd Party app (NGINX) with helm

Jenkinsfile

• Staging
  • local: localhost:30006
  • remote: scripts/get-remote-url nginx fluxv1-staging
• Production
  • local: localhost:30007
  • remote: scripts/get-remote-url nginx fluxv1-production

Flux V2

PetClinic with plain k8s resources

Jenkinsfile

• Staging
  • local: localhost:30010
  • remote: scripts/get-remote-url spring-petclinic-plain fluxv2-staging
• Production
  • local: localhost:30011
  • remote: scripts/get-remote-url spring-petclinic-plain fluxv2-production

ArgoCD

PetClinic with plain k8s resources

Jenkinsfile for plain deployment

• Staging
  • local localhost:30020
  • remote: scripts/get-remote-url spring-petclinic-plain argocd-staging
• Production
  • local localhost:30021
  • remote: scripts/get-remote-url spring-petclinic-plain argocd-production

PetClinic with helm

Jenkinsfile for helm deployment

• Staging
  • local localhost:30022
  • remote: scripts/get-remote-url spring-petclinic-helm argocd-staging
• Production
  • local localhost:30023
  • remote: scripts/get-remote-url spring-petclinic-helm argocd-production

3rd Party app (NGINX) with helm

Jenkinsfile

• Staging
  • local: localhost:30006
  • remote: scripts/get-remote-url nginx fluxv1-staging
• Production
  • local: localhost:30007
  • remote: scripts/get-remote-url nginx fluxv1-production

Testing

There is an end to end testing script inside the ./scripts folder. It scans for builds and starts them, waits until their finished or fail and returns the result.

Usage

You can use it by executing groovy ./scripts/e2e.groovy --url http://localhost:9090 --user admin --password admin

Options

• help - Print this help text and exit
• url - The Jenkins-URL to connect to
• user- The Jenkins-User for login
• password - Jenkins-Password for login
• fail - Exit on first build failure
• interval - Interval for waits while scanning for builds
• debug - Set log level to debug