{"record":{"id":"92796bbfd0840222","repo":"kubernetes/kops","slug":"error-hashing-data-v","errorCode":null,"errorMessage":"error hashing data: %v","messagePattern":"error hashing data: (.+?)","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"util/pkg/hashing/hash.go","lineNumber":152,"sourceCode":"\treturn &Hash{Algorithm: ha, HashValue: hasher.Sum(nil)}, nil\n}\n\nfunc (ha HashAlgorithm) HashFile(p string) (*Hash, error) {\n\tf, err := os.OpenFile(p, os.O_RDONLY, 0)\n\tif err != nil {\n\t\tif os.IsNotExist(err) {\n\t\t\treturn nil, err\n\t\t}\n\t\treturn nil, fmt.Errorf(\"error opening file %q: %v\", p, err)\n\t}\n\tdefer try.CloseFile(f)\n\treturn ha.Hash(f)\n}\n\nfunc copyToHasher(dest io.Writer, src io.Reader) (int64, error) {\n\tn, err := io.Copy(dest, src)\n\tif err != nil {\n\t\treturn n, fmt.Errorf(\"error hashing data: %v\", err)\n\t}\n\treturn n, nil\n}\n\nfunc (l *Hash) Equal(r *Hash) bool {\n\treturn (l.Algorithm == r.Algorithm) && bytes.Equal(l.HashValue, r.HashValue)\n}\n","sourceCodeStart":134,"sourceCodeEnd":160,"githubUrl":"https://github.com/kubernetes/kops/blob/4c8573c808a73d578c5eadc86d410646ea0b0d73/util/pkg/hashing/hash.go#L134-L160","documentation":"copyToHasher performs io.Copy from the source reader into the hasher and wraps any copy failure as 'error hashing data'. This is the inner I/O failure surfaced by HashAlgorithm.Hash (and indirectly HashFile) — the data stream could not be read to completion.","triggerScenarios":"Any Hash/HashFile call where the underlying reader errors mid-copy: network interruption during asset download, disk read error, closed file descriptor, or a reader implementation returning an error.","commonSituations":"Unstable network while verifying remote asset hashes; reading from a file on a failing disk; readers that error on EOF handling; concurrent modification of the file being hashed.","solutions":["Retry the hashing operation; transient I/O errors often resolve","Check disk health and file availability at the source path/URL","Look at the wrapped cause (%v) for the concrete I/O error and address it directly","Stage data locally first, then hash the local copy to isolate download vs hashing failures"],"exampleFix":"// before\nh, err := algo.Hash(remoteReader)\n// after\ntmp, err := os.CreateTemp(\"\", \"asset\")\nif err != nil { return err }\nif _, err := io.Copy(tmp, remoteReader); err != nil { return fmt.Errorf(\"download: %w\", err) }\ntmp.Seek(0, 0)\nh, err := algo.Hash(tmp)","handlingStrategy":"try-catch","validationCode":"null","typeGuard":"null","tryCatchPattern":"h, err := algo.Hash(r)\nif err != nil {\n\tif strings.Contains(err.Error(), \"error hashing data\") {\n\t\treturn fmt.Errorf(\"source stream failed during hashing: %w; retry the operation\", err)\n\t}\n\treturn err\n}","preventionTips":["Read sources to completion locally before hashing to isolate I/O failures","Retry transient network/disk errors with backoff","Avoid hashing readers that are concurrently written or closed","Monitor disk health on nodes where verification runs"],"tags":["hashing","io","copy"],"backgroundTag":"io-read-failure","analyzedSha":"4c8573c808a73d578c5eadc86d410646ea0b0d73","analyzedAt":"2026-09-05T04:13:19.212Z","contentChangedAt":"2026-09-05T04:13:19.212Z","schemaVersion":2},"datasetVersion":"2026-09-12T07:17:12.445Z"}