sources/hetzner: integrate private networks metadata

[tboerger]

Proposed Commit Message

feat(hetzner): integrate private networks metadata

Additional Context

I'm not a python developer and don't entirely understand the tests, maybe somebody can help me? I want to use the change to automatically reference IPs of the assigned private networks via Jinja within my cloud-init configuration.

If you request the external-networks endpoint from a Hetzner Cloud instance you receive a response like this:

# curl http://169.254.169.254/hetzner/v1/metadata/private-networks
- ip: 10.30.0.3
  alias_ips: []
  interface_num: 1
  mac_address: 86:00:00:c3:10:7f
  network_id: 13011151
  network_name: mgmt
  network: 10.30.0.0/18
  subnet: 10.30.0.0/22
  gateway: 10.30.0.1

After applying my change I can query the metadata properly including the attached private networks to properly configure services within cloud-init with the private networks to avoid listening on public interfaces:

# cloud-init query ds.meta_data.private_networks
{
 "mgmt": {
  "alias_ips": [],
  "gateway": "10.30.0.1",
  "interface_num": 1,
  "ip": "10.30.0.3",
  "mac_address": "86:00:00:c3:10:7f",
  "network": "10.30.0.0/18",
  "network_id": 13011151,
  "network_name": "mgmt",
  "subnet": "10.30.0.0/22"
 }
}

Test Steps

Merge type

• [x] Squash merge using "Proposed Commit Message"
• [ ] Rebase and merge unique commits. Requires commit messages per-commit each referencing the pull request number (#<PR_NUM>)

[tboerger]

@asciiprod maybe you can take a look at it and suggest improvements? :)

[TheRealFalcon]

@tboerger , with the conversation happening here, is this PR still in progress, or do you believe it is ready to merge?

[tboerger]

I think it makes sense to follow the provided comments.

[github-actions[bot]]

Hello! Thank you for this proposed change to cloud-init. This pull request is now marked as stale as it has not seen any activity in 14 days. If no activity occurs within the next 7 days, this pull request will automatically close.

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[tboerger]

Dann, I really forgot about this PR

[martinblascop]

@tboerger I have the same use case, are you still planning on working on this?

[tboerger]

Let's see if I can integrate the feedback today to get this done.

[tboerger]

@skoch-hc with the last change I started using read_metadata to fetch the private networks. I can also confirm that cloud-init query ds.meta_data.private_networks is working as expected. I have stopped transforming the response and I will stick with the {% set network = ds.meta_data["private-networks"] | selectattr("network_name", "equalto", "cloud-init-test") | first %} example to get the IP of the first network.

Please review and hopefully accept this change now :)

[skoch-hc]

Looks good to me, also tested it quickly and works as expected. Can be merged from my side.

root@test-server:~# cloud-init query ds.meta_data.private-networks
[
 {
  "alias_ips": [],
  "gateway": "10.2.0.1",
  "interface_num": 2,
  "ip": "10.2.0.2",
  "mac_address": "86:00:00:b5:6f:a9",
  "network": "10.2.0.0/16",
  "network_id": 10222253,
  "network_name": "test-server-2",
  "subnet": "10.2.0.0/24"
 },
 {
  "alias_ips": [],
  "gateway": "192.168.0.1",
  "interface_num": 1,
  "ip": "192.168.0.2",
  "mac_address": "86:00:00:b5:6f:ab",
  "network": "192.168.0.0/16",
  "network_id": 4493592,
  "network_name": "test-server",
  "subnet": "192.168.0.0/24"
 }
]
root@test-server:~# cloud-init query -f '{% set network = ds.meta_data["private-networks"] | selectattr("network_name", "equalto", "test-server") | first%}{{ network.ip }}'
192.168.0.2
root@test-server:~# cloud-init query -f '{% set network = ds.meta_data["private-networks"] | selectattr("network_name", "equalto", "test-server-2") | first%}{{ network.ip }}'
10.2.0.2

[skoch-hc]

It seems it still needs an approval from somebody with "write access", probably a cloud-init maintainer.

[tboerger]

@TheRealFalcon is there something I have to do?

[TheRealFalcon]

@tboerger , thanks for the ping. I'll review and merge if there are no outstanding issues.

[johnhamelink]

Hi, am I correct in saying that this PR hasn't made it into a release yet? I'm using nixpkgs unstable to install cloud-init which is ostensibly v25.2 (package source here: https://github.com/NixOS/nixpkgs/blob/nixos-unstable/pkgs/tools/virtualization/cloud-init/default.nix), and I don't see these changes in DataSourceHetzner.py in the installed package. I tried to use this PR to apply a patch to the 25.2 source but it doesn't apply cleanly.

Thanks! JH

[tboerger]

You can see at https://github.com/canonical/cloud-init/blob/25.2/cloudinit/sources/DataSourceHetzner.py#L108 that it is part of the tag.