Re: [PATCH proxmox-backup 3/7] api: add /nodes/localhost/instance-id

[Christian Ebner <c.ebner@proxmox.com>]

On 4/13/26 2:11 PM, Lukas Wagner wrote:
> This one returns a unique ID that can be used to uniquely identify a PBS
> node. This will be used by PDM to match PBS storages in a PVE cluster to
> PBS remotes in PDM, mainly for associating backup jobs with the
> appropriate PBS remote. Later we can also use this to match PBS sync
> jobs to their matching PBS remotes in PDM.
> 
> The instance ID is derived from /etc/machine-id as recommended by
> systemd [1] by using proxmox_systemd::sd_id128::get_app_specific_id.
> 
> [1] https://www.freedesktop.org/software/systemd/man/latest/sd_id128_get_machine_app_specific.html
> 
> Signed-off-by: Lukas Wagner <l.wagner@proxmox.com>
> ---
>   src/api2/node/mod.rs | 41 ++++++++++++++++++++++++++++++++++++++++-
>   1 file changed, 40 insertions(+), 1 deletion(-)
> 
> diff --git a/src/api2/node/mod.rs b/src/api2/node/mod.rs
> index 42e1dbaa2..93770c4f5 100644
> --- a/src/api2/node/mod.rs
> +++ b/src/api2/node/mod.rs
> @@ -25,7 +25,7 @@ use proxmox_schema::*;
>   use proxmox_sortable_macro::sortable;
>   use proxmox_sys::fd::fd_change_cloexec;
>   
> -use pbs_api_types::{NodeShellTicket, NODE_SCHEMA, PRIV_SYS_CONSOLE};
> +use pbs_api_types::{InstanceId, NodeShellTicket, NODE_SCHEMA, PRIV_SYS_CONSOLE};
>   use tracing::{info, warn};
>   
>   use crate::auth::{private_auth_keyring, public_auth_keyring};
> @@ -291,12 +291,51 @@ fn list_nodes() -> Result<Value, Error> {
>       Ok(json!([ { "node": proxmox_sys::nodename().to_string() } ]))
>   }
>   
> +///  Static key used for deriving a unique instance id from `/etc/machine-id` using
> +///  [`proxmox_systemd::sd_id128::get_app_specific_id`].
> +///
> +///  This key was generated `systemd-id128 new`.

nit: ... generated by `systemd-id128 new`

> +///
> +const INSTANCE_ID_KEY: [u8; 16] = 0xe5415d9999c146399b8bdae1260e19d2_u128.to_le_bytes();
> +
> +#[api(
> +    protected: false,

nit: no need to set this explicitly.

> +    input: {
> +        properties: {
> +            node: {
> +                schema: NODE_SCHEMA,
> +                optional: true,
> +            },
> +        }
> +    },
> +    returns: {
> +        type: InstanceId,
> +    },
> +    access: {
> +        permission: &Permission::Anybody,
> +    }
> +)]
> +/// Returns a unique ID for this PBS node. The ID is derived from `/etc/machine-id`.
> +pub fn get_instance_id() -> Result<InstanceId, Error> {
> +    let machine_id_derived_app_id =
> +        proxmox_systemd::sd_id128::get_app_specific_id(INSTANCE_ID_KEY)?;
> +    let machine_id_derived_app_id = hex::encode(machine_id_derived_app_id);
> +
> +    Ok(InstanceId {
> +        instance_id: machine_id_derived_app_id,

nit: Could make sense to derive `From` for this on the `InstanceId` itself?

But do not want to pollute the api-types with dependencies on 
proxmox-systemd, so this would only cover the plain id to string 
conversion... so not sure if worth it.

> +    })
> +}
> +
>   pub const SUBDIRS: SubdirMap = &[
>       ("apt", &apt::ROUTER),
>       ("certificates", &certificates::ROUTER),
>       ("config", &config::ROUTER),
>       ("disks", &disks::ROUTER),
>       ("dns", &dns::ROUTER),
> +    (
> +        "instance-id",
> +        &Router::new().get(&API_METHOD_GET_INSTANCE_ID),
> +    ),
>       ("journal", &journal::ROUTER),
>       ("network", &network::ROUTER),
>       ("report", &report::ROUTER),