Migrate from Flux v1 to v2
This guide walks you through migrating from Flux v1 to v2. Read the FAQ to find out what differences are between v1 and v2.
Prerequisites
You will need a Kubernetes cluster version 1.20 or newer and kubectl version 1.20 or newer.
Install Flux v2 CLI
With Homebrew:
brew install fluxcd/tap/flux
With Bash:
curl -s https://fluxcd.io/install.sh | sudo bash
# enable completions in ~/.bash_profile
. <(flux completion bash)
Command-line completion for zsh, fish, and powershell
are also supported with their own sub-commands.
Binaries for macOS, Windows and Linux AMD64/ARM are available for download on the release page.
Verify that your cluster satisfies the prerequisites with:
flux check --pre
GitOps migration
Flux v2 offers an installation procedure that is declarative first and disaster resilient.
Using the flux bootstrap command you can install Flux on a
Kubernetes cluster and configure it to manage itself from a Git
repository. The Git repository created during bootstrap can be used
to define the state of your fleet of Kubernetes clusters.
For a detailed walk-through of the bootstrap procedure please see the installation guide.
'flux bootstrap' target
flux bootstrap should not be run against a Git branch or path
that is already being synchronized by Flux v1, as this will make
them fight over the resources. Instead, bootstrap to a new Git
repository, branch or path, and continue with moving the
manifests.After you’ve installed Flux v2 on your cluster using bootstrap, you can delete the Flux v1 from your clusters and move the manifests from the Flux v1 repository to the bootstrap one. Typically deleting Flux v1 can be done by deleting these helm installations: flux and helm-operator
One key change in Flux v2 is “server-side apply” that enforces strict validation of the manifests. It is important to note that manifests are applied atomically to the cluster only if server side validation of the apply passes. If one Kustomization has multiple resources, an error in any one of the resources will also prevent other resources in that group from getting applied. This is a breaking change from Flux v1.
In-place migration
Flux read-only mode
Assuming you’ve installed Flux v1 to sync a directory with plain YAMLs from a private Git repo:
# create namespace
kubectl create ns flux
# deploy Flux v1
fluxctl install \
--git-url=git@github.com:org/app \
--git-branch=main \
--git-path=./deploy \
--git-readonly \
--namespace=flux | kubectl apply -f -
# print deploy key
fluxctl identity --k8s-fwd-ns flux
# trigger sync
fluxctl sync --k8s-fwd-ns flux
Uninstall Flux v1
Before you proceed, scale the Flux v1 deployment to zero or delete its namespace and RBAC.If there are YAML files in your deploy dir that are not meant to be
applied on the cluster, you can exclude them by placing a .sourceignore in your repo root:
$ cat .sourceignore
# exclude all
/*
# include deploy dir
!/deploy
# exclude files from deploy dir
/deploy/**/eksctl.yaml
/deploy/**/charts
Install Flux v2 in the flux-system namespace:
$ flux install \
--network-policy=true \
--watch-all-namespaces=true \
--namespace=flux-system
✚ generating manifests
✔ manifests build completed
► installing components in flux-system namespace
✔ install completed
◎ verifying installation
✔ source-controller ready
✔ kustomize-controller ready
✔ helm-controller ready
✔ notification-controller ready
✔ install finished
Register your Git repository and add the deploy key with read-only access:
$ flux create source git app \
--url=ssh://git@github.com/org/app \
--branch=main \
--interval=1m
► generating deploy key pair
ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQCp2x9ghVmv1zD...
Have you added the deploy key to your repository: y
► collecting preferred public key from SSH server
✔ collected public key from SSH server:
github.com ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEAq2A...
► applying secret with keys
✔ authentication configured
✚ generating GitRepository source
► applying GitRepository source
✔ GitRepository source created
◎ waiting for GitRepository source reconciliation
✔ GitRepository source reconciliation completed
✔ fetched revision: main@sha1:5302d04c2ab8f0579500747efa0fe7abc72c8f9b
Configure the reconciliation of the deploy dir on your cluster:
$ flux create kustomization app \
--source=GitRepository/app \
--path="./deploy" \
--prune=true \
--interval=10m
✚ generating Kustomization
► applying Kustomization
✔ Kustomization created
◎ waiting for Kustomization reconciliation
✔ Kustomization app is ready
✔ applied revision main@sha1:5302d04c2ab8f0579500747efa0fe7abc72c8f9b
If your repository contains secrets encrypted with Mozilla SOPS, please read this guide.
Pull changes from Git and apply them immediately:
flux reconcile kustomization app --with-source
List all Kubernetes objects reconciled by app:
kubectl get all --all-namespaces \
-l=kustomize.toolkit.fluxcd.io/name=app \
-l=kustomize.toolkit.fluxcd.io/namespace=flux-system
Flux with Kustomize
Assuming you’ve installed Flux v1 to sync a Kustomize overlay from an HTTPS Git repository:
fluxctl install \
--git-url=https://github.com/org/app \
--git-branch=main \
--manifest-generation \
--namespace=flux | kubectl apply -f -
With the following .flux.yaml in the root dir:
version: 1
patchUpdated:
generators:
- command: kustomize build ./overlays/prod
patchFile: flux-patch.yaml
Uninstall Flux v1
Before you proceed, delete the Flux v1 namespace and remove the.flux.yaml from your repo.Install Flux v2 in the flux-system namespace:
flux install
Register the Git repository using a personal access token:
flux create source git app \
--url=https://github.com/org/app \
--branch=main \
--username=git \
--password=token \
--interval=1m
Configure the reconciliation of the prod overlay on your cluster:
flux create kustomization app \
--source=GitRepository/app \
--path="./overlays/prod" \
--prune=true \
--interval=10m
Check the status of the Kustomization reconciliation:
$ flux get kustomizations app
NAME REVISION SUSPENDED READY
app main@sha1:5302d04c2ab8f0579500747efa0fe7abc72c8f9b False True
Flux with Slack notifications
Assuming you have configured Flux v1 to send notifications to Slack with FluxCloud.
With Flux v2, create an alert provider for a Slack channel:
flux create alert-provider slack \
--type=slack \
--channel=some-channel-name \
--address=https://hooks.slack.com/services/YOUR/SLACK/WEBHOOK
And configure notifications for the app reconciliation events:
flux create alert app \
--provider-ref=slack \
--event-severity=info \
--event-source=GitRepository/app \
--event-source=Kustomization/app
For more details, read the guides on how to configure notifications and webhooks.
Flux debugging
Check the status of Git operations:
$ kubectl -n flux-system get gitrepositories
NAME READY MESSAGE
app True Fetched revision: main@sha1:5302d04c2ab8f0579500747efa0fe7abc72c8f9b
test False SSH handshake failed: unable to authenticate, attempted methods [none publickey]
Check the status of the cluster reconciliation with kubectl:
$ kubectl -n flux-system get kustomizations
NAME READY STATUS
app True Applied revision: main@sha1:5302d04c2ab8f0579500747efa0fe7abc72c8f9
test False The Service 'backend' is invalid: spec.type: Unsupported value: 'Ingress'
Suspend a reconciliation:
$ flux suspend kustomization app
► suspending kustomization app in flux-system namespace
✔ kustomization suspended
Check the status with kubectl:
$ kubectl -n flux-system get kustomization app
NAME READY STATUS
app False Kustomization is suspended, skipping reconciliation
Resume a reconciliation:
$ flux resume kustomization app
► resuming Kustomization app in flux-system namespace
✔ Kustomization resumed
◎ waiting for Kustomization reconciliation
✔ Kustomization reconciliation completed
✔ applied revision main@sha1:5302d04c2ab8f0579500747efa0fe7abc72c8f9b