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[PUBM-51741] BYOLinux: mention runcmd to replace postInstallationScript #18

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Merged
sbraz merged 1 commit into from
Mar 16, 2026
+30 −2
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[PUBM-51741] BYOLinux: mention runcmd to replace postInstallationScript #18

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32 changes: 30 additions & 2 deletions README.md
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Original file line number Diff line number Diff line change
Expand Up @@ -163,18 +163,44 @@ You can use a home-made script with a payload like this one:
{
"operatingSystem": "byolinux_64",
"customizations": {
"hostname": "myHostname",
"hostname": "mon-tux",
"imageURL": "https://github.com/myself/myImagesFactory/releases/download/0.1/myCustomImage.qcow2",
"imageCheckSum": "6a65719e6a7f276a4b8685d3ace0920d56acef7d4bbbf9427fe188db7b19c23be7fc182f7a9b29e394167717731f4cd7cab410a36e60e6c6451954f3b795a15c",
"httpHeaders": {
"Authorization": "Basic dGhlb3dsc2FyZW5vdDp3aGF0dGhleXNlZW1z="
},
"imageCheckSumType": "sha512",
"configDriveUserData": "#!/bin/bash\necho \"Hi, sounds like BYOLinux as ostemplate is a success!\" >/etc/motd"
"configDriveUserData": "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"
}
}
```

The `configDriveUserData` field above is base64-encoded. Here is the clear-text version:
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@ashmonger ashmonger Mar 16, 2026

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Top ça


```yaml
#cloud-config
ssh_authorized_keys:
- ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIAbcD myself@mydomain.net

users:
- name: patient0
sudo: ALL=(ALL) NOPASSWD:ALL
groups: users, sudo
shell: /bin/bash
lock_passwd: false
ssh_authorized_keys:
- ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIAbcD myself@mydomain.net
disable_root: false
packages:
- vim
- tree
runcmd:
- echo "coucou runcmd" > /opt/coucou
- cat /etc/machine-id >> /opt/coucou
- date "+%Y-%m-%d %H:%M:%S" --utc >> /opt/coucou
final_message: The system is finally up, after $UPTIME seconds
```

The key elements here are:

- `operatingSystem`: which is `byolinux_64`
Expand All @@ -183,6 +209,8 @@ The key elements here are:
In this example, we use Basic authentication
- The other items in `customizations` are self-explanatory

> **Note:** Unlike standard OVHcloud OS templates (e.g. Debian 12, Windows Server), BYOLinux does not support the `postInstallationScript` customization option. To run commands or scripts after installation, use `configDriveUserData` with a cloud-init [`runcmd`](https://cloudinit.readthedocs.io/en/latest/reference/modules.html#runcmd) directive instead.

<a name="manager"></a>

### Via the [OVHcloud Control Panel](https://www.ovh.com/manager/#/dedicated/configuration)
Expand Down