docs: update for OEM images

README.md

@@ -1,46 +1,43 @@
 # Build Flatcar Snapshots on Hetzner Cloud with Packer
 
-> [!IMPORTANT]
-> This version of the README describes the process to build & test Hetzner OEM images using the Draft PR [flatcar/scripts#1880](https://github.com/flatcar/scripts/pull/1880).
-> If you are a user looking to install Flatcar on Hetzner Cloud right now, you can check out the [`main` branch](https://github.com/apricote/flatcar-packer-hcloud/) of this repo.
-
 ## Requirements
 
 - [Hetzner Cloud API Token](https://docs.hetzner.com/cloud/api/getting-started/generating-api-token/)
 - [Packer](https://developer.hashicorp.com/packer)
 - [Hetzner Cloud CLI](https://github.com/hetznercloud/cli) (`hcloud`)
 
-## Building Snapshots
+This requires Flatcar version `3941.1.0+`.
 
-In Hetzner Cloud, you can create a "Snapshot" of your server's disk. You can then use these snapshots to create new servers.
+## 1. Building Snapshots
 
-We will use Packer and the `flatcar-install` script to write the pre-built images from Flatcar CI to the disk and then create a snapshot.
+In Hetzner Cloud, you can create a "Snapshot" of your server's disk. You can then use these snapshots to create new
+servers.
+
+We will use Packer and the `flatcar-install` script to write the pre-built images from Flatcar CI to the disk and then
+create a snapshot.
 
 ```shell
-$ git clone --branch oem-image-prebuilt https://github.com/apricote/flatcar-packer-hcloud.git
+$ git clone https://github.com/apricote/flatcar-packer-hcloud.git
 $ cd flatcar-packer-hcloud
 $ export HCLOUD_TOKEN=<Your Hetzner Cloud API Token>
 $ packer init .
 
-# This will build the Snapshot for x86. You need to specify the path to your local image file.
+# This will build the snapshot for x86 and Arm.
 $ packer build .
 # ... Takes a few minutes
-# It sometimes hangs on "==> hcloud.x86: + trap - EXIT", running with `PACKER_LOG=1` fixes it for me.
 ==> Builds finished. The artifacts of successful builds are:
---> hcloud.x86: A snapshot was created: 'flatcar-x86' (ID: 157132241)
+--> hcloud.x86: A snapshot was created: 'flatcar-beta-3941.1.0-x86' (ID: 157132241)
---> hcloud.arm: A snapshot was created: 'flatcar-arm' (ID: 157132242)
+--> hcloud.arm: A snapshot was created: 'flatcar-beta-3941.1.0-arm' (ID: 157132242)
 
 $ hcloud image list --type=snapshot --selector=os=flatcar
-ID          TYPE       NAME   DESCRIPTION   ARCHITECTURE   IMAGE SIZE   DISK SIZE   CREATED                        DEPRECATED
+ID          TYPE       NAME   DESCRIPTION                 ARCHITECTURE   IMAGE SIZE
-157132241   snapshot   -      flatcar-x86   x86            0.47 GB      20 GB       Sat Mar 30 16:48:22 CET 2024   -
+167650172   snapshot   -      flatcar-beta-3941.1.0-arm   arm            0.41 GB
-157132242   snapshot   -      flatcar-arm   arm            0.44 GB      20 GB       Sat Mar 30 16:48:22 CET 2024   -
+167650577   snapshot   -      flatcar-beta-3941.1.0-x86   x86            0.47 GB
 ```
 
-## Create a Server
+## 2. Create a Server
 
-You can now create a new server from the snapshot. Not every feature might automatically work, as the snapshot is
+You can now create a new server from the snapshot. Configuring SSH Keys and User Data (Ignition) will work as expected.
-missing the functionality from [`hc-utils`](https://github.com/hetznercloud/hc-utils). Configuring SSH Keys and User
-Data (Ignition) will work as expected.
 
 ```shell
 # Get ID of the most recent flatcar snapshot for x86
@@ -54,3 +51,40 @@ $ hcloud server create --name flatcar-test --image $SNAPSHOT_ID --type cx11 --ss
 # Now you can login, the following is a helper that calls `ssh` with the public ipv4 address of the server
 $ hcloud server ssh -u core flatcar-test
 ```
+
+## Options
+
+If you need to configure the Flatcar installation or the resulting image, there are a few packer variables that you can
+set.
+
+- `channel`: To choose a different Flatcar channel, defaults to `beta` (as `stable` does not have Hetzner images yet)
+- `version`: If you want to install a specific version, defaults to `current`
+- `labels`: See [section below](#labels)
+
+### Labels
+
+The `labels` variable controls the labels that are added to the resulting image. This can be helpful if you use a tool
+that requires specific image labels, like `caph-image-name`
+for [`cluster-api-provider-hetzner`](https://github.com/syself/cluster-api-provider-hetzner/blob/v1.0.0-beta.35/docs/topics/node-image.md#creating-a-node-image).
+
+The following variables are supported:
+
+- `$architecture`: The Hetzner Cloud API architecture (`x86` or `arm`).
+- `$board`: The Flatcar Board identifier for the architecture (`amd64-usr` or `arm64-usr`).
+- `$version`: The Flatcar version, if you are using `current`, this is resolved to the actual version in the snapshot.
+- `$channel`: The Flatcar release channel.
+
+The default labels are:
+
+- `os=flatcar`
+- `flatcar-channel=$channel`
+- `flatcar-board=$board`
+- `version=$version`
+- `architecture=$architecture`
+
+## Known Issues
+
+These features do not work with Flatcar as of version 3941.1.0:
+
+- **Volume Automount**: You need to mount volumes manually.
+- **Setting & Resetting Root Passwords**: You need to configure an SSH Key through the API or Ignition User Data.