Resolve node.attr.zone via the Node label instead of cloud IMDS - #900
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Resolve node.attr.zone via the Node label instead of cloud IMDS#900goat-ssh wants to merge 1 commit into
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CrateDB's node.attr.zone (used for zone-aware shard allocation) was queried per-provider from each cloud's instance metadata service at 169.254.169.254. That endpoint needs pod egress to survive on all four providers, and it's a classic SSRF/pivot target — closing it off at the NetworkPolicy layer (crate/cloud#3850, crate/cloud#3851) breaks zone detection on every cluster. Read the pod's own Node object via the in-cluster API server instead: the topology.kubernetes.io/zone label is already populated consistently by AWS, Azure, GCP and STACKIT's cloud-controller-managers. One code path for all four providers, and no pod egress to IMDS required. Requires a ClusterRole/ClusterRoleBinding granting the cluster's default ServiceAccount read-only access to its own Node object; the binding is per-cluster and explicitly cleaned up on delete, since a namespaced CrateDB CR can't own a cluster-scoped object via owner_references. Every provider's crate pod restarts once to pick up the new command and NODE_NAME env var.
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September 4, 2026 13:48
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Summary of changes
CrateDB's node.attr.zone (used for zone-aware shard allocation) was queried per-provider from each cloud's instance metadata service at 169.254.169.254. That endpoint needs pod egress to survive on all four providers, and it's a classic SSRF/pivot target — closing it off at the NetworkPolicy layer (crate/cloud#3850, crate/cloud#3851) breaks zone detection on every cluster.
Read the pod's own Node object via the in-cluster API server instead: the topology.kubernetes.io/zone label is already populated consistently by AWS, Azure, GCP and STACKIT's cloud-controller-managers. One code path for all four providers, and no pod egress to IMDS required.
Requires a ClusterRole/ClusterRoleBinding granting the cluster's default ServiceAccount read-only access to its own Node object; the binding is per-cluster and explicitly cleaned up on delete, since a namespaced CrateDB CR can't own a cluster-scoped object via owner_references.
Every provider's crate pod restarts once to pick up the new command and NODE_NAME env var.
Checklist
CHANGES.rst