flux2/docs/get-started/index.md

# Get started with GitOps Toolkit

## Prerequisites

You will need a Kubernetes cluster version 1.14 or newer and kubectl version 1.18.
For a quick local test, you can use `minikube`, `kubeadm` or `kind`.
Any other Kubernetes setup will work as well though.

In order to follow the guide you'll need a GitHub account and a 
[personal access token](https://help.github.com/en/github/authenticating-to-github/creating-a-personal-access-token-for-the-command-line)
that can create repositories.

Export your GitHub personal access token and username:

```sh
export GITHUB_TOKEN=<your-token>
export GITHUB_USER=<your-username>
```

## Install the toolkit CLI

To install the latest `tk` release run:

```bash
curl -s https://toolkit.fluxcd.io/install.sh | sudo bash
```

The install script downloads the tk binary to `/usr/local/bin`.
Binaries for macOS and Linux AMD64 are available for download on the 
[release page](https://github.com/fluxcd/toolkit/releases).

To configure your shell to load tk completions add to your bash profile:

```sh
# ~/.bashrc or ~/.bash_profile
. <(tk completion)
```

## GitOps workflow

You'll be using a dedicated Git repository e.g. `fleet-infra` to manage one or more Kubernetes clusters.
This guide assumes that you have two clusters, one for staging and one for production.

Using the toolkit CLI you'll do the following:

- configure each cluster to synchronise with a directory inside the fleet repository
- register app sources (git repositories) that contain plain Kubernetes manifests or Kustomize overlays
- configure app deployments on both clusters (pre-releases on staging, semver releases on production)

## Staging bootstrap

Verify that your staging cluster satisfies the prerequisites with:

```text
$ tk check --pre

► checking prerequisites
✔ kubectl 1.18.3 >=1.18.0
✔ kubernetes 1.16.8-eks-e16311 >=1.14.0
✔ prerequisites checks passed
```

Run the bootstrap command:

```sh
tk bootstrap github \
  --owner=$GITHUB_USER \
  --repository=fleet-infra \
  --path=staging-cluster \
  --personal
```

The bootstrap command creates a repository if one doesn't exist and
commits the toolkit components manifests to the master branch at the specified path.
Then it configures the target cluster to synchronize with the specified path inside the repository.

If you wish to create the repository under a GitHub organization:

```sh
tk bootstrap github \
  --owner=<organization> \
  --repository=<repo-name> \
  --team=<team1-slug> \
  --team=<team2-slug> \
  --path=staging-cluster
```

Example output:

```text
$ tk bootstrap github --owner=gitopsrun --repository=fleet-infra --path=staging-cluster --team=devs

► connecting to github.com
✔ repository created
✔ devs team access granted
✔ repository cloned
✚ generating manifests
✔ components manifests pushed
► installing components in gitops-system namespace
namespace/gitops-system created
customresourcedefinition.apiextensions.k8s.io/gitrepositories.source.fluxcd.io created
customresourcedefinition.apiextensions.k8s.io/helmcharts.source.fluxcd.io created
customresourcedefinition.apiextensions.k8s.io/helmrepositories.source.fluxcd.io created
customresourcedefinition.apiextensions.k8s.io/kustomizations.kustomize.fluxcd.io created
customresourcedefinition.apiextensions.k8s.io/profiles.kustomize.fluxcd.io created
role.rbac.authorization.k8s.io/crd-controller-gitops-system created
rolebinding.rbac.authorization.k8s.io/crd-controller-gitops-system created
clusterrolebinding.rbac.authorization.k8s.io/cluster-reconciler-gitops-system created
service/source-controller created
deployment.apps/kustomize-controller created
deployment.apps/source-controller created
networkpolicy.networking.k8s.io/deny-ingress created
Waiting for deployment "source-controller" rollout to finish: 0 of 1 updated replicas are available...
deployment "source-controller" successfully rolled out
deployment "kustomize-controller" successfully rolled out
✔ install completed
► configuring deploy key
✔ deploy key configured
► generating sync manifests
✔ sync manifests pushed
► applying sync manifests
◎ waiting for cluster sync
✔ bootstrap finished
```

If you prefer GitLab, export `GITLAB_TOKEN` env var and use the command [tk bootstrap gitlab](../cmd/tk_bootstrap_gitlab.md).

!!! hint
    It is safe to run the bootstrap command as many times as you want.
    If the toolkit components are present on the cluster,
    the bootstrap command will perform an upgrade if needed.

## Staging workflow

Clone the repository with:

```sh
git clone https://github.com/$GITHUB_USER/fleet-infra
cd fleet-infra
```

Create a git source pointing to a public repository master branch:

```sh
tk create source git webapp \
  --url=https://github.com/stefanprodan/podinfo \
  --branch=master \
  --interval=30s \
  --export > ./staging-cluster/webapp-source.yaml
```

Create a kustomization for synchronizing the common manifests on the cluster:

```sh
tk create kustomization webapp-common \
  --source=webapp \
  --path="./deploy/webapp/common" \
  --prune=true \
  --validate=client \
  --interval=1h \
  --export > ./staging-cluster/webapp-common.yaml
```

Create a kustomization for the backend service that depends on common: 

```sh
tk create kustomization webapp-backend \
  --depends-on=webapp-common \
  --source=webapp \
  --path="./deploy/webapp/backend" \
  --prune=true \
  --validate=client \
  --interval=10m \
  --health-check="Deployment/backend.webapp" \
  --health-check-timeout=2m \
  --export > ./staging-cluster/webapp-backend.yaml
```

Create a kustomization for the frontend service that depends on backend: 

```sh
tk create kustomization webapp-frontend \
  --depends-on=webapp-backend \
  --source=webapp \
  --path="./deploy/webapp/frontend" \
  --prune=true \
  --validate=client \
  --interval=10m \
  --health-check="Deployment/frontend.webapp" \
  --health-check-timeout=2m \
  --export > ./staging-cluster/webapp-frontend.yaml
```

Push changes to origin:

```sh
git add -A && git commit -m "add staging webapp" && git push
```

In about 30s the synchronization should start:

```text
$ watch tk get kustomizations

✔ gitops-system last applied revision master/35d5765a1acb9e9ce66cad7274c6fe03eee1e8eb
✔ webapp-backend reconciling
✔ webapp-common last applied revision master/f43f9b2eb6766e07f318d266a99d2ec7c940b0cf
✗ webapp-frontend dependency 'gitops-system/webapp-backend' is not ready
```

When the synchronization finishes you can check that the webapp services are running:

```text
$ kubectl -n webapp get deployments,services

NAME                       READY   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/backend    1/1     1            1           4m1s
deployment.apps/frontend   1/1     1            1           3m31s

NAME               TYPE        CLUSTER-IP    EXTERNAL-IP   PORT(S)             AGE
service/backend    ClusterIP   10.52.10.22   <none>        9898/TCP,9999/TCP   4m1s
service/frontend   ClusterIP   10.52.9.85    <none>        80/TCP              3m31s
```

!!! note
    From this moment forward, any changes made to the webapp
    master branch will be synchronised with the cluster.

If a Kubernetes manifest is removed from source, the reconclier will remove it from your cluster. If you
delete a kustomization from the fleet infra repo, the reconciler will remove all Kubernetes objects that
were previously applied from that kustomization.

If you alter the webapp deployment using `kubectl edit`, the changes will be reverted to match
the state described in git. When dealing with an incident, you can pause the recitation of a
kustomization with `tk suspend kustomization <name>`. Once the debugging session
is over, you can re-enable the reconciliation with `tk resume kustomization <name>`.

## Production bootstrap 

On production clusters, you may wish to deploy stable releases of an application.
When creating a git source instead of a branch, you can specify a git tag or a semver expression. 

Change your kubectl context to a different cluster and run the bootstrap for the production environment:

```sh
tk bootstrap github \
  --owner=$GITHUB_USER \
  --repository=fleet-infra \
  --path=prod-cluster \
  --personal
```

Pull the changes locally:

```sh
git pull
```

## Production workflow

Create a git source using a semver range to target stable releases:

```sh
tk create source git webapp \
  --url=https://github.com/stefanprodan/podinfo \
  --tag-semver=">=4.0.0 <4.0.2" \
  --interval=30s \
  --export > ./prod-cluster/webapp-source.yaml
```

Create a kustomization for webapp pointing to the production overlay:

```sh
tk create kustomization webapp \
  --source=webapp \
  --path="./deploy/overlays/production" \
  --prune=true \
  --validate=client \
  --interval=10m \
  --health-check="Deployment/frontend.production" \
  --health-check="Deployment/backend.production" \
  --health-check-timeout=2m \
  --export > ./prod-cluster/webapp-production.yaml
``` 

Push changes to origin:

```sh
git add -A && git commit -m "add prod webapp" && git push
```

List git sources:

```text
$ tk get sources git

✔ gitops-system last fetched revision master/99072ee132abdead8b7799d7891eae2f524eb73d
✔ webapp last fetched revision 4.0.1/113360052b3153e439a0cf8de76b8e3d2a7bdf27
```

The kubectl equivalent is `kubectl -n gitops-system get gitrepositories`.

List kustomization:

```text
$ tk get kustomizations

✔ gitops-system last applied revision master/99072ee132abdead8b7799d7891eae2f524eb73d
✔ webapp last applied revision 4.0.1/113360052b3153e439a0cf8de76b8e3d2a7bdf27
```

The kubectl equivalent is `kubectl -n gitops-system get kustomizations`.

If you want to upgrade to the latest 4.x version, you can change the semver expression to:

```sh
tk create source git webapp \
  --url=https://github.com/stefanprodan/podinfo \
  --tag-semver=">=4.0.0 <5.0.0" \
  --interval=30s \
  --export > ./prod-cluster/webapp-source.yaml

git add -A && git commit -m "update prod webapp" && git push
```

Trigger a git sync:

```text
$ tk sync ks gitops-system --with-source 

► annotating source gitops-system
✔ source annotated
◎ waiting for git sync
✔ git sync completed
✔ fetched revision master/d751ea264d48bf0db8b588d1d08184834ac8fec9
◎ waiting for kustomization sync
✔ kustomization sync completed
✔ applied revision master/d751ea264d48bf0db8b588d1d08184834ac8fec9
```

The kubectl equivalent is `kubectl -n gitops-system annotate gitrepository/gitops-system source.fluxcd.io/syncAt="$(date +%s)"`.

Wait for the webapp to be upgraded:

```text
$ watch tk get kustomizations

✔ gitops-system last applied revision master/d751ea264d48bf0db8b588d1d08184834ac8fec9
✔ webapp last applied revision 4.0.5/f43f9b2eb6766e07f318d266a99d2ec7c940b0cf
```