unkinben
e60080efa2
The dynamic mode produced a byte-identical cluster to authoritative:
RFC2136 update capability is a per-zone property (BindZone.dynamicUpdate
+ updateKeyRef render allow-update { key ... }), not a cluster role. The
external-dns tier is just an authoritative cluster whose zones allow
dynamic updates.
- remove BindMode dynamic from the enum and constants
- switch the external-dns sample to mode authoritative
- update README migration mapping
101 lines
4.3 KiB
Markdown
101 lines
4.3 KiB
Markdown
# bind-operator
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A Kubernetes operator that manages fleets of BIND9 servers declaratively:
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StatefulSet-backed clusters with primary/secondary replication, and zones,
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views, TSIG keys, ACLs, catalog zones, RPZ policies and DNSSEC policies as
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custom resources.
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## Architecture
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Each `BindCluster` is a StatefulSet plus a headless Service (stable per-pod DNS)
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and a client Service. **Ordinal-0 is the primary**; the remaining pods are
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secondaries that replicate via AXFR/IXFR + NOTIFY. A per-pod PVC holds zone
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databases and journals.
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Zone content is delivered **dynamically**: the operator execs `rndc addzone` and
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TSIG `nsupdate` against the primary pod (the same write path external-dns uses).
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Cluster-wide config — `options`, `controls`, ACLs, views, `dnssec-policy` blocks
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and `response-policy` clauses — is rendered into a ConfigMap-backed `named.conf`
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and reloaded with `rndc reconfig`. New zones land on the secondaries
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automatically through a **catalog zone**, so secondaries never need
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per-zone reconfiguration.
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```
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BindCluster ──> StatefulSet (pod-0 = primary, pod-N = secondaries)
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├─ headless Service (pod-0.<cluster>-headless.<ns>.svc…)
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├─ client Service (ClusterIP / LoadBalancer)
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├─ ConfigMap (named.conf.primary / .secondary + entrypoint)
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├─ Secret <cluster>-keys (TSIG key clauses, included by named.conf)
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└─ Secret <cluster>-rndc (rndc control key)
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BindZone / DNSRecord ──rndc addzone + nsupdate──> primary ──catalog + AXFR──> secondaries
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```
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The named.conf is rendered in two variants (primary/secondary); an entrypoint
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script picks one based on the pod ordinal.
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## Custom Resources
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| Kind | Purpose |
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|------|---------|
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| `BindCluster` | A set of BIND9 servers. `spec.mode`: `authoritative` or `resolver`. |
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| `BindZone` | A forward/reverse zone (`primary`/`secondary`/`forward`/`stub`), records inline, optional dynamic-update + DNSSEC + catalog membership. |
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| `DNSRecord` | A single record set applied via TSIG `nsupdate` — external-dns as a CRD. |
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| `BindView` | A split-horizon view (`match-clients`, ordering, per-view recursion). |
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| `BindTSIGKey` | A TSIG key; the operator generates material into a Secret (never stored in the CR). |
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| `BindACL` | A reusable named `address_match_list`. |
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| `BindCatalogZone` | A BIND catalog zone so secondaries auto-provision member zones. |
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| `BindPolicy` | A Response Policy Zone (RPZ) / DNS firewall. |
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| `BindDNSSECPolicy` | A `dnssec-policy` for automated signing. |
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See `config/samples/` for worked examples.
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## Migration mapping
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The three Puppet-managed BIND roles map onto three `BindCluster`s:
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| Puppet role | `BindCluster` | Mode |
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|-------------|---------------|------|
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| 3× authoritative masters | `auth` | `authoritative` (pod-0 primary, 2 secondaries) |
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| 3× only-resolvers | `resolver` | `resolver` (3 identical recursive servers) |
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| 3× external-dns | `externaldns` | `authoritative` (zones set `dynamicUpdate` for RFC2136 TSIG updates) |
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## Development
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```sh
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make generate # regenerate deepcopy, CRDs and RBAC from kubebuilder markers
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make build # build the operator binary
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make test # go test -race
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make lint fmt # go vet / gofmt
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```
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### Local (kind)
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```sh
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kind create cluster --name bind
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docker build -t bind-operator:dev -f Dockerfile.operator .
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kind load docker-image bind-operator:dev --name bind
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kubectl apply -f config/crd/bases/
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kubectl apply -f hack/kind/manifests/
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kubectl apply -f config/samples/
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```
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## CI
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Woodpecker runs `pre-commit` (gofmt + vet), `test`, and a dry-run image `build`
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on pull requests; pushing a `v*` tag builds and pushes
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`git.unkin.net/unkin/bind-operator` to the Gitea registry.
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## Notes & caveats
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- The BIND container image (`spec.image`, default
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`internetsystemsconsortium/bind9:9.20`) must ship `named`, `rndc` and
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`nsupdate`. The operator projects its config at `/etc/bind-operator` (leaving
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the image's own `/etc/bind`, including `bind.keys`, intact) and runs
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`named -g -c /run/named/named.conf`.
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- Dynamic updates authenticate with `nsupdate -y`; the TSIG secret is passed on
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the argv of an exec'd process inside the pod.
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- RPZ IP-trigger encodings (`ip`, `client-ip`, `nsip`) are emitted verbatim;
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QNAME and NSDNAME triggers are fully supported.
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