{"record":{"id":"1cf831c4bb163e0c","repo":"kubernetes/kops","slug":"headbucket-on-q-did-not-return-a-bucket-region","errorCode":null,"errorMessage":"HeadBucket on %q did not return a bucket region","messagePattern":"HeadBucket on %q did not return a bucket region","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"util/pkg/vfs/s3context.go","lineNumber":300,"sourceCode":"}\n\n// bucketLocationViaHead resolves the region for a bucket using HeadBucket.\n// GetBucketLocation does not work for cross-account buckets queried from a different region.\n// HeadBucket can be called against any region in the partition: on success the response carries\n// BucketRegion, and on a cross-region failure (e.g. 301 PermanentRedirect) S3 still sets the\n// x-amz-bucket-region response header, which we recover from the wrapped response error.\nfunc bucketLocationViaHead(ctx context.Context, s3Client *s3.Client, bucket string) (string, error) {\n\tctx, span := tracer.Start(ctx, \"bucketLocationViaHead\")\n\tdefer span.End()\n\n\tout, err := s3Client.HeadBucket(ctx, &s3.HeadBucketInput{\n\t\tBucket: aws.String(bucket),\n\t})\n\tif err == nil {\n\t\tif out.BucketRegion != nil && *out.BucketRegion != \"\" {\n\t\t\treturn *out.BucketRegion, nil\n\t\t}\n\t\treturn \"\", fmt.Errorf(\"HeadBucket on %q did not return a bucket region\", bucket)\n\t}\n\n\tvar respErr *smithyhttp.ResponseError\n\tif errors.As(err, &respErr) && respErr.Response != nil && respErr.Response.Response != nil {\n\t\tif bucketRegion := respErr.Response.Header.Get(\"x-amz-bucket-region\"); bucketRegion != \"\" {\n\t\t\treturn bucketRegion, nil\n\t\t}\n\t}\n\treturn \"\", fmt.Errorf(\"getting location for bucket %q: %w\", bucket, err)\n}\n\n// isRunningOnEC2 determines if we could be running on EC2.\n// It is used to avoid a call to the metadata service to get the current region,\n// because that call is slow if not running on EC2\nfunc isRunningOnEC2(ctx context.Context) (bool, error) {\n\tif runtime.GOOS == \"linux\" {\n\t\t// Approach based on https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/identify_ec2_instances.html\n\t\tproductUUID, err := os.ReadFile(\"/sys/devices/virtual/dmi/id/product_uuid\")","sourceCodeStart":282,"sourceCodeEnd":318,"githubUrl":"https://github.com/kubernetes/kops/blob/4c8573c808a73d578c5eadc86d410646ea0b0d73/util/pkg/vfs/s3context.go#L282-L318","documentation":"Returned by bucketLocationViaHead when a HeadBucket call succeeds (or fails with a redirect) but the response contains no bucket region — neither the BucketRegion field nor the x-amz-bucket-region header. The bucket may be unreachable, the credentials wrong, or an atypical S3-compatible endpoint that omits region headers, leaving region resolution impossible.","triggerScenarios":"Thrown at util/pkg/vfs/s3context.go:300 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":["Retry the HeadBucket call — transient intermediary responses sometimes omit the header","Verify the bucket exists and credentials allow HeadBucket on it","For S3-compatible endpoints, ensure the endpoint actually implements HeadBucket region reporting or configure the region explicitly"],"exampleFix":null,"handlingStrategy":"retry","validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"4c8573c808a73d578c5eadc86d410646ea0b0d73","analyzedAt":"2026-09-05T04:13:19.212Z","contentChangedAt":"2026-09-05T04:13:19.212Z","schemaVersion":2},"datasetVersion":"2026-09-12T12:17:11.808Z"}