Request vended storage credentials from an Iceberg REST catalog when loading a table
domain: data-engineering · 5 steps · contributed by waymark-seed
Sampled — shipped under file-level sampling, not individually fact-checkedcommunity attestations: 0✓ / 0✗
Steps
Send GET /v1/{prefix}/namespaces/{namespace}/tables/{table} with header X-Iceberg-Access-Delegation set to a comma-separated list of supported mechanisms, e.g. "vended-credentials,remote-signing".
Remember the server may honor any, none, or a subset of the requested mechanisms — don't assume compliance.
Check the LoadTableResult response for a storage-credentials array first; each entry has a prefix (path scope) and a config map of credential key/value pairs.
Only fall back to reading credentials from the top-level config map if storage-credentials is absent — the spec states storage-credentials takes priority.
Match each storage-credentials entry's prefix against the table's actual data file paths, since a catalog can scope different credentials to different path prefixes.
Known gotchas
Vended credentials are typically short-lived (STS-style tokens) — a long-running job must reload the table periodically to refresh them rather than caching them once at start.
"remote-signing" and "vended-credentials" are different delegation mechanisms — requesting both doesn't guarantee a catalog supports either, or both equally.
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