lxd: friendly errror with suggestions if network is broken
Metadata
Current evaluation
Merged in snapcraft#1930 (cdbac658d), replacing raw LXD network-probe failures with friendly errors that include the checked URL and guidance.
Resolution: closed resolved
Reason: Pull request #1930 was approved and merged as commit cdbac658d, adding explicit network exception handling and updating unit tests.
Evaluated by: mr-cal-bot
No scores available.
Issue body
- [x] Have you followed the [guidelines for contributing](https://github.com/snapcore/snapcraft/blob/master/CONTRIBUTING.md)?
- [x] Have you signed the [CLA](http://www.ubuntu.com/legal/contributors/)?
- [x] If this is a bugfix. Have you checked that there is a bug report open for the issue you are trying to fix on [bug reports](https://bugs.launchpad.net/snapcraft)?
- [x] If this is a new feature. Have you discussed the design on the [forum](https://forum.snapcraft.io)?
- [x] Have you successfully run `./runtests.sh static`?
- [x] Have you successfully run `./runtests.sh unit`?
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As evidenced by [LP: #1749679](https://bugs.launchpad.net/snapcraft/+bug/1749679) the verbatim network probing failures aren't very helpful. We can try to reduce noise and give some hints as to what's wrong. `ContainerConnectionError` will ensure there's a link to LXD docs and the URL we check is mentioned in the message.
`urllib.error.URLError` is handled explicitly to get a niceish error message in the case of connection errors. All other exceptions will generically be caught as well since we don't want a stack trace in any event and **urllib** can leak other exceptions such as `UnicodeError`.
Fixes: [LP: #1719952](https://bugs.launchpad.net/snapcraft/+bug/1719952)
The following tests were updated:
- tests.unit.commands.test_snap
- tests.unit.test_lxd
I locally ran the tests:
- `./runtests.sh tests/unit` with unrelated failures in [tests.unit.test_lifecycle.CoreSetupTestCase.test_core_setup_if_docker_env](https://bugs.launchpad.net/snapcraft/+bug/1752576), `tests.unit.test_mangling.TestClearExecstack.test_execstack_clears` and `tests.unit.test_elf`.
- `./runtests.sh tests/integration` with one unrelated failure in [tests.integration.general.test_parser.TestParserWikis](https://bugs.launchpad.net/snapcraft/+bug/1752580)
- `./runtests.sh static`: Everything passed
Manual test steps:
- cd tests/integration/snaps/basic
- snapcraft cleanbuild
- lxc profile set default environment.http_proxy localhost:1234
- Observe `Failed to open 'http://start.ubuntu.com/connectivity-check.html': [Errno 111] Connection refused`
- lxc profile set default environment.http_proxy invalid
- Observe `Failed to open 'http://start.ubuntu.com/connectivity-check.html': [Errno -2] Name or service not known`
- lxc profile set default environment.http_proxy http://unknown
- Observe `Failed to open 'http://start.ubuntu.com/connectivity-check.html': [Errno -2] Name or service not known`
- lxc profile set default environment.http_proxy .invalid
- Observe `Failed to open 'http://start.ubuntu.com/connectivity-check.html': encoding with 'idna' codec failed (UnicodeError: label empty or too long)`
Note: Use `lxc profile set default environment.http_proxy ''` to unset the proxy in the default LXD profile after testing, or set it to the value you were using previously.
Evaluation history
| Date | Model | Scores | Action | Summary |
|---|---|---|---|---|
| stealth/space-bunny-alpha | — | closed resolved | Merged in snapcraft#1930 (cdbac658d), replacing raw LXD network-probe failures with friendly errors that include the checked URL and guidance. | |
| stealth/space-bunny-alpha | — | closed resolved | Merged in snapcraft#1930 (cdbac658d), adding friendly LXD network failure messages, explicit exception handling, the checked URL, and updated tests. | |
| qwen/qwen3.6-35b-a3b | — | — | Merged improvements to LXD network error handling replace raw stack traces with user-friendly messages and troubleshooting hints. The update explicitly catches connection and encoding exceptions, updates tests, and resolves Launchpad bug #1719952. | |
| qwen3.6-35b-a3b-mtp-q6 | — | — | Merged. Replaces raw LXD network traces with user-friendly error messages and hints. Handles urllib and container exceptions to prevent stack traces, updates tests, and resolves LP: #1719952. |
Update history
No update history recorded yet.
Related issues
| Issue | Project | State | Summary | Similarity |
|---|---|---|---|---|
| #343 lxd should be a suggestion, not a direct dep | snapcraft | merged | Merged in snapcraft PR #343 as 7147a43ba, changing LXD from a direct dependency to a suggestion and resolving LP #1550381. | |
| #1647 lxd: better surfacing of errors | snapcraft | merged | Merged in snapcraft#1647 as commit 71f48bdc9, improving LXD error handling so callers return silent, correctly coded errors without printing messages twice. | |
| #1550381 lxd should be a suggestion, not a direct dependency | snapcraft (launchpad) | closed | LXD was changed from a direct dependency to a suggestion in canonical/snapcraft PR #343 (commit 7147a43ba), resolving Launchpad #1550381. |