gitops.md

Ignite - the GitOps VM

Ignite is a “GitOps-first” project, GitOps is supported out of the box using the ignited gitops command. Previously this was integrated as ignite gitops, but this functionality has now moved to ignited, Ignite's upcoming daemon binary.

In Git you declaratively store the desired state of a set of VMs you want to manage. ignited gitops reconciles the state from Git, and applies the desired changes as state is updated in the repo. It also commits and pushes any local changes/additions to the managed VMs back to the repository.

This can then be automated, tracked for correctness, and managed at scale - just some of the benefits of GitOps.

The workflow is simply this:

• Run ignited gitops [repo], where repo is an SSH url to your Git repo
• Create a file with the VM specification, specifying how much vCPUs, RAM, disk, etc. you’d like for the VM
• Run git push and see your VM start on the host

See it in action! (Note: The screencast is from an older version which differs somewhat)

Try it out

Go ahead and create a Git repository.

NOTE: You need an SSH key for root that has push access to your repository. ignited will commit and push changes back to the repository using the default key for it. To edit your root's git configuration, run sudo gitconfig --global --edit. The root requirement will be removed in a future release.

Here's a sample configuration you can push to it (my-vm.yaml):

apiVersion: ignite.weave.works/v1alpha4
kind: VM
metadata:
  name: my-vm
  uid: 599615df99804ae8
spec:
  image:
    oci: weaveworks/ignite-ubuntu
  cpus: 2
  diskSize: 3GB
  memory: 800MB
  ssh: true
status:
  running: true

NOTE: uid must be set. VM configurations without uid are ignored.

For a more complete example repository configuration, see luxas/ignite-gitops

After you have installed Ignite, you can do the following:

ignited gitops git@github.com:<user>/<repository>.git

NOTE: HTTPS doesn't preserve authentication information for ignited to push changes, you need to set up SSH authentication and use the SSH clone URL for now.

Ignite will now search that repo for suitable JSON/YAML files, and apply their state locally. You should see my-vm starting up in ignite ps. To enter the VM, run ignite ssh my-vm.

Using a local git repo for testing

Create a new directory and initialize it as a bare git repo. For ignited to push updates to the git repo, the repo must be created as a bare git repo.

$ mkdir ~/ignite-gitops
$ cd ~/ignite-gitops
$ git init --bare
$ ls
HEAD  branches  config  description  hooks  info  objects  refs

Clone this git repo and add the sample VM configuration:

$ git clone file:///home/user/ignite-gitops ignite-gitops-clone
Cloning into 'ignite-gitops-clone'...
warning: You appear to have cloned an empty repository.
$ cd ignite-gitops-clone
$ git remote -v
origin	file:///home/user/ignite-gitops (fetch)
origin	file:///home/user/ignite-gitops (push)
$ # Create my-vm.yaml, commit and push.

Run ignited against the bare git repo:

$ sudo ignited gitops file:///home/user/ignite-gitops
INFO[0000] Starting GitOps loop for repo at "file:///home/user/ignite-gitops"
INFO[0000] Whenever changes are pushed to the target branch, Ignite will apply the desired state locally
INFO[0000] Initializing the Git repo...
INFO[0000] Running in read-write mode, will commit back current status to the repo
INFO[0000] Starting the commit loop...
INFO[0000] Starting the checkout loop...
INFO[0000] Starting to clone the repository file:///home/user/ignite-gitops with timeout 1m0s
INFO[0000] New commit observed on branch "master": 7095d3603649792f44110cc5cf7deb0ded897e4b. User initiated: true
INFO[0003] Creating VM "599615df99804ae8" with name "my-vm"...
INFO[0004] Starting VM "599615df99804ae8" with name "my-vm"...
INFO[0004] Networking is handled by "cni"
INFO[0004] Started Firecracker VM "599615df99804ae8" in a container with ID "ignite-599615df99804ae8"
...
INFO[0030] A new commit with the actual state has been created and pushed to the origin: "186a8eb6eced5843480d4a10872db071ecc76439"
INFO[0030] New commit observed on branch "master": 186a8eb6eced5843480d4a10872db071ecc76439. User initiated: false
...

NOTE: Root permission may be required to push updates to the main repo because ignited pushes git updates as root.

Please refer to docs/declarative-config.md for the full API reference.