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gitops-playground

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Reproducible infrastructure to showcase GitOps workflows with Kubernetes.

In fact, this rolls out a complete DevOps stack with different features including

  • GitOps (with different controllers to choose from: Argo CD, Flux v1 and v2),
  • example applications and CI-pipelines (using Jenkins and our GitOps library),
  • Notifications/Alerts (using Mailhog for Demo purposes)
  • Monitoring (using Prometheus and Grafana),
  • Secrets management (using Vault).

The gitops-playground is derived from our experiences in consulting, operating the myCloudogu platform and is used in our GitOps trainings for both Flux and ArgoCD.
For questions or suggestions you are welcome to join us at our myCloudogu community forum.

Discuss it on myCloudogu

Playground features

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 --pull=always -u $(id -u) \
    -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.
Note that you can append --argocd, --fluxv1 and --fluxv2 to select specific operators. This will also speed up the progress.

We recommend running this command as an unprivileged user, that is inside the docker group.

Table of contents

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, Argo CD). 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, including more advanced use cases like notifications and monitoring.

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 below show an overview of the playground's architecture and three scenarios for running the playground. For a simpler overview including all optional features such as monitoring and secrets management see intro at the very top.

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
Playground on local machine
Demo on remote cluster
Playground on remote cluster
Production environment with CES
A possible production environment

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 below.

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

Note:

  • docker pull in advance makes sure you have the newest image, even if you ran this command before.
    Of course, you could also specify a specific version of the image.
  • 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.
  • We run as the local user in order to avoid file permission issues with the kubeconfig-${CLUSTER_NAME}.yaml.
  • If you experience issues and want to access the full log files, use the following command while the container is running:
docker exec -it \
  $(docker ps -q  --filter ancestor=ghcr.io/cloudogu/gitops-playground) \
  bash -c -- 'tail -f  -n +1 /tmp/playground-log-*'

Apply via kubectl (remote cluster)

For remote clusters it is easiest to apply the playground via kubectl. You can find info on how to install kubectl here.

# 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=Never \
  --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 Argo CD 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 Argo CD 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 Argo CD 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
Argo CD-Notifications

If you are using a remote cluster you can set the --argocd-url parameter so that argocd-notification messages have a link to the corresponding application.

Monitoring

Set the parameter --monitoring to enable deployment of monitoring and alerting tools like prometheus, grafana and mailhog.

See Monitoring tools for details.

Secrets Management

Set the parameter --vault=[dev|prod] to enable deployment of secret management tools hashicorp vault and external secrets operator. See Secrets management tools for details.

Remove playground

For k3d, you can just k3d cluster delete gitops-playground. This will delete the whole cluster. If you just want to remove the playground from the cluster, use this script: './scripts/destroy.sh'

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
  • Argo CD
  • Demo applications for each GitOps operator, each with staging and production instance.

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

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, Argo CD and others can be accessed via: admin/admin

Note that you can change (an should for a remote cluster!) the password with the --password argument. There also is a --username parameter, which is ignored for argocd. That is, for now argos username ist always admin.

Jenkins

Jenkins is available at

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://.

Enable Jenkins Notifications

Example of a Jenkins browser notifications

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

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

Monitoring tools

Set the parameter --monitoring so the kube-prometheus-stack via its helm-chart is being deployed including Argo CD dashboards.

This leads to the following tools to be exposed:

Grafana can be used to query and visualize metrics via prometheus. Prometheus is not exposed by default.

In addition, argocd-notifications is set up. Applications deployed with Argo CD now will alert via email to mailhog the sync status failed, for example.

Note that this only works with Argo CD so far

Secrets Management Tools

Via the vault parameter, you can deploy Hashicorp Vault and the External Secrets Operator into your GitOps playground.

With this, the whole flow from secret value in Vault to kubernetes Secret via External Secrets Operator can be seen in action:

External Secret Operator <-> Vault - flow

For this to work, the GitOps playground configures the whole chain in Kubernetes and vault (when dev mode is used):

External Secret Operator Custom Resources

  • In k8s namespaces argocd-staging and argocd-production:
    • Creates SecretStore and ServiceAccount (used to authenticate with vault)
    • Creates ExternalSecrets
  • In Vault:
    • Create secrets for staging and prod
    • Create a human user for changing the secrets
    • Authorizes the service accounts on those secrets
  • Creates an example app that uses the secrets

dev mode

For testing you can set the parameter --vault=dev to deploy vault in development mode. This will lead to

  • vault being transient, i.e. all changes during runtime are not persisted. Meaning a restart will reset to default.
  • Vault is initialized with some fixed secrets that are used in the example app, see bellow.
  • Vault authorization is initialized with service accounts used in example SecretStores for external secrets operator
  • Vault is initialized with the usual admin/admin account (can be overriden with --username and --password)

The secrets are then picked up by the vault-backend SecretStores (connects External Secrets Operator with Vault) in the namespace argocd-staging and argocd-production namespaces

You can reach the vault UI on

  • http://localhost:8200 (k3d)
  • scripts/get-remote-url vault-ui secrets (remote k8s)
  • You can log in vie the user account mentioned above.
    If necessary, the root token can be found on the log:
    kubectl logs -n secrets vault-0 | grep 'Root Token'

prod mode

When using vault=prod you'll have to initialize vault manually but on the other hand it will persist changes.

If you want the example app to work, you'll have to manually

  • set up vault, unseal it and
  • authorize the vault service accounts in argocd-production and argocd-staging namspaces. See SecretStores and dev-post-start.sh for an example.

Example app

With vault in dev mode and ArgoCD enabled, the demo app applications/nginx/argocd/helm-jenkins will be deployed in a way that exposes the vault secrets secret/<stage>/nginx-secret via HTTP on the URL http://<host>/secret, for example http://localhost:30024/secret.

While exposing secrets on the web is a very bad practice, it's very good for demoing auto reload of a secret changed in vault.

To demo this, you could

  • change the staging secret
  • Wait for the change to show on the web, e.g. like so
while ; do echo -n "$(date '+%Y-%m-%d %H:%M:%S'): " ; curl http://localhost:30024/secret/ ; echo; sleep 1; done

This usually takes between a couple of seconds and 1-2 minutes.
This time consists of ExternalSecret's refreshInterval, as well as the kubelet sync period (defaults to 1 Minute)

  • cache propagation delay

Argo CD UI

Argo CD's web UI is available at

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

Argo CD

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, templated in Jenkins

Jenkinsfile

  • Staging
    • local: localhost:30024
    • remote: scripts/get-remote-url nginx argocd-staging
  • Production
    • local: localhost:30025
    • remote: scripts/get-remote-url nginx argocd-production
3rd Party app (NGINX) with helm, using Helm dependency mechanism
  • local: localhost:30026
  • remote: scripts/get-remote-url nginx argocd-staging

Development

See docs/developers.md