feat: implement dns controllers

Author: zachsmith1

.github/workflows/publish.yml

@@ -0,0 +1,33 @@
+name: Publish Docker Image
+
+on:
+  # Trigger on push
+  push:
+  # Trigger on all pull requests
+  pull_request:
+  # Trigger when a release is published
+  release:
+    types: ['published']
+
+jobs:
+  publish-container-image:
+    permissions:
+      id-token: write
+      contents: read
+      packages: write
+      attestations: write
+    uses: datum-cloud/actions/.github/workflows/publish-docker.yaml@v1.5.1
+    with:
+      image-name: dns-operator
+    secrets: inherit
+
+  publish-kustomize-bundles:
+    permissions:
+      id-token: write
+      contents: read
+      packages: write
+    uses: datum-cloud/actions/.github/workflows/publish-kustomize-bundle.yaml@v1.5.1
+    with:
+      bundle-name: ghcr.io/datum-cloud/dns-operator-kustomize
+      bundle-path: config
+    secrets: inherit

.github/workflows/test-e2e.yml

@@ -10,7 +10,10 @@
 
 bin/
 vendor/
+dist/
+dev/
 .go-version
+config/**/charts
 
 # Test binary, built with `go test -c`
 *.test

.gitignore

@@ -26,6 +26,8 @@ linters:
       rules:
         - name: comment-spacings
         - name: import-shadowing
+    gocyclo:
+      min-complexity: 70
   exclusions:
     generated: lax
     rules:

.golangci.yml

@@ -34,4 +34,13 @@ resources:
   kind: DNSRecordSet
   path: go.miloapis.com/dns-operator/api/v1alpha1
   version: v1alpha1
+- api:
+    crdVersion: v1
+    namespaced: true
+  controller: true
+  domain: networking.miloapis.com
+  group: dns
+  kind: DNSZoneDiscovery
+  path: go.miloapis.com/dns-operator/api/v1alpha1
+  version: v1alpha1
 version: "3"

LICENSE

@@ -1 +1,135 @@
-# dns-operator
+## datum-dns-operator
+
+Kubernetes operator for managing DNS zones and records, with a pluggable backend architecture. This repository provides:
+- Custom resources to model zones, recordsets, and zone classes
+- Controllers for two runtime roles:
+  - "downstream" agent that programs a DNS backend (PowerDNS supported)
+  - "replicator" that mirrors resources from an upstream cluster to a downstream cluster and synthesizes status
+- Kustomize overlays to deploy either role
+
+### CRDs
+- **`DNSZoneClass`** (cluster-scoped)
+  - `spec.controllerName`: selects backend controller (e.g., "powerdns")
+  - `spec.nameServerPolicy`: currently supports `Static` with `servers: []`
+  - `spec.defaults.defaultTTL`: optional default TTL for zones
+
+- **`DNSZone`** (namespaced)
+  - `spec.domainName`: required zone FQDN (e.g., `example.com`)
+  - `spec.dnsZoneClassName`: optional reference to a `DNSZoneClass`
+  - `status.nameservers`: authoritative nameservers (derived from class policy)
+  - `status.conditions`: `Accepted`, `Programmed`
+
+- **`DNSRecordSet`** (namespaced)
+  - `spec.dnsZoneRef`: `LocalObjectReference` to a `DNSZone` in the same namespace
+  - `spec.recordType`: one of `A, AAAA, CNAME, TXT, MX, SRV, CAA, NS, SOA, PTR, TLSA, HTTPS, SVCB`
+  - `spec.records[]`: owners with typed fields per record type (or `raw` strings). TTL per-owner optional.
+  - `status.conditions`: `Accepted`, `Programmed`
+
+### Controllers and Roles
+
+- **Downstream role** (`--role=downstream`)
+  - `DNSZoneReconciler`: when `DNSZone.spec.dnsZoneClassName` references a class with `controllerName: powerdns`, ensures the zone exists in PowerDNS and honors static nameserver policy.
+  - `DNSRecordSetReconciler`: for PowerDNS-backed zones, applies recordsets to PDNS using an authoritative mode that REPLACEs desired owners and DELETEs extraneous owners of the same type. Requeues while the zone is not ready.
+
+- **Replicator role** (`--role=replicator`)
+  - Multicluster manager discovers one or many upstream clusters (single-cluster or Milo discovery) and mirrors `DNSZone`/`DNSRecordSet` into a configured downstream cluster using a mapped-namespace strategy.
+  - `DNSZoneReplicator`:
+    - Mirrors upstream `spec` into a downstream shadow object
+    - Ensures an operator-managed upstream `DNSRecordSet` named `soa` exists (typed SOA targeting `@`) for PowerDNS-backed zones
+    - Updates upstream `status`: sets `Accepted=True` and currently treats `Programmed=True` optimistically; fills `status.nameservers` from `DNSZoneClass` when `Static` policy is set
+  - `DNSRecordSetReplicator`:
+    - Mirrors upstream `spec` into a downstream shadow object
+    - Updates upstream `status`: `Accepted` reflects `DNSZone` presence; `Programmed=True` once downstream shadow ensured
+
+### Backends
+- **PowerDNS (Authoritative)**
+  - Enabled when `DNSZoneClass.spec.controllerName: powerdns`
+  - The downstream agent uses environment variables to connect:
+    - `PDNS_API_URL` (default `http://127.0.0.1:8081`)
+    - `PDNS_API_KEY` or `PDNS_API_KEY_FILE`
+  - Recordset translation supports typed fields for all declared RR types and sensible normalization of names and quoting for TXT/targets.
+
+### Deployment Overlays
+
+- `config/agent/`
+  - Namespace: `dns-agent-system`
+  - Runs the operator with `--role=downstream`
+  - Merges a `pdns` sidecar container into the controller Deployment to run PowerDNS alongside the manager
+  - Mounts a shared `emptyDir` to exchange an auto-generated API key, and sets `PDNS_API_KEY_FILE` in the manager
+  - Provides a `Service` exposing PDNS ports 53/udp, 53/tcp, and 8081/tcp
+  - ConfigMap `server-config` wired to `--server-config`
+
+- `config/overlays/replicator/`
+  - Namespace: `dns-replicator-system`
+  - Runs the operator with `--role=replicator`
+  - Requires a Secret `downstream-kubeconfig` containing key `kubeconfig` to target the downstream cluster
+  - ConfigMap `server-config` sets discovery mode (defaults to `single`) and points `downstreamResourceManagement.kubeconfigPath` to `/downstream/kubeconfig`
+
+### Quickstart: Agent with embedded PowerDNS
+1. Install CRDs and default manifests:
+   - `kubectl apply -k config/agent`
+2. Create a `DNSZoneClass` for PowerDNS with static nameservers, for example:
+```yaml
+apiVersion: dns.networking.miloapis.com/v1alpha1
+kind: DNSZoneClass
+metadata:
+  name: powerdns
+spec:
+  controllerName: powerdns
+  nameServerPolicy:
+    mode: Static
+    static:
+      servers: ["ns1.example.net.", "ns2.example.net."]
+```
+3. Create a `DNSZone` and a `DNSRecordSet`:
+```yaml
+apiVersion: dns.networking.miloapis.com/v1alpha1
+kind: DNSZone
+metadata:
+  name: example-com
+  namespace: default
+spec:
+  domainName: example.com
+  dnsZoneClassName: powerdns
+---
+apiVersion: dns.networking.miloapis.com/v1alpha1
+kind: DNSRecordSet
+metadata:
+  name: www-a
+  namespace: default
+spec:
+  dnsZoneRef:
+    name: example-com
+  recordType: A
+  records:
+    - name: www
+      a:
+        content: ["192.0.2.10", "192.0.2.11"]
+      ttl: 300
+```
+
+### Quickstart: Replicator (upstream → downstream)
+1. Create Secret on the replicator namespace containing the downstream kubeconfig (`data.kubeconfig`):
+```bash
+kubectl -n dns-replicator-system create secret generic downstream-kubeconfig \
+  --from-file=kubeconfig=/path/to/downstream/kubeconfig
+```
+2. Deploy replicator overlay:
+```bash
+kubectl apply -k config/overlays/replicator
+```
+3. Create `DNSZoneClass` (cluster-scoped), `DNSZone` and `DNSRecordSet` on the upstream cluster. The replicator will mirror them into the downstream cluster and update upstream `status` conditions.
+
+### Conditions
+- `Accepted`: resource is valid and has required dependencies (e.g., `DNSRecordSet` sees its `DNSZone`)
+- `Programmed`: desired state is realized (shadow exists downstream; for downstream agent, recordsets applied to backend)
+
+### Configuration CRD (server config)
+- `kind: DNSOperator` (internal config consumed by the binary via `--server-config`)
+  - `discovery.mode`: `single` or `milo`
+  - `downstreamResourceManagement.kubeconfigPath`: path inside the Pod to the downstream kubeconfig
+
+### Development
+- Build: `make docker-build` (see `Makefile`)
+- Generate code/manifests: `make generate` and `make manifests`
+- Local e2e: see `test/e2e/chainsaw-test.yaml` and sample manifests under `config/samples/`