Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

isMetadataEndpointAccessible is not reliable #42452

Closed
howardjohn opened this issue Dec 14, 2022 · 1 comment · Fixed by #42450
Closed

isMetadataEndpointAccessible is not reliable #42452

howardjohn opened this issue Dec 14, 2022 · 1 comment · Fixed by #42450
Assignees
@howardjohn

Comments

@howardjohn
Copy link
Member

howardjohn commented Dec 14, 2022 •
edited

isMetadataEndpointAccessible attempts to check we can actually reach the GCE server.

We use this along with metada.OnGCE

Logic:
OnGCE: first one wins of

  • "curl 169.254.169.254" has Metadata-Flavor==Google
  • dig metadata.google.internal contains 169.254.169.254

We add isMetadataEndpointAccessible which does a simple curl of metadata.google.internal and sees it is reachable. This doesn't seem reliable

  1. The actual requests use 169.254.169.254, so reachability to that is all the is relevant
  2. DNS lookup of metadata.google.internal is unsafe, see TestVMTelemetry flaky, regression #42449 and metadata: issue with DNS search googleapis/google-cloud-go#7165
@howardjohn
Copy link
Member Author

cc @rinormaloku @stewartbutler

@howardjohn howardjohn self-assigned this Dec 15, 2022
@howardjohn howardjohn mentioned this issue Dec 15, 2022
Merged
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Assignees

@howardjohn howardjohn

Labels
None yet
Projects
None yet
Milestone
No milestone
Development

Successfully merging a pull request may close this issue.

Fix VM DNS in tests howardjohn/istio
1 participant
@howardjohn