[infra] Partial Calico adoption: namespaces only (Wave 5b)
## Context
Wave 5b of the state-drift consolidation plan. Calico has run this cluster's
pod networking since 2024-07-30, installed via raw kubectl manifests —
tigera-operator Deployment + ~20 CRDs + an Installation CR. The plan
flagged Calico as HIGH BLAST because the operator + Installation CR sit on
the critical path for pod scheduling; any mistake during adoption can
break CNI and block new pods cluster-wide within seconds.
This session takes the safe sub-step: adopt only the three namespaces.
Namespaces are label containers — TF managing their names + PSA labels
cannot disrupt Calico networking. Getting the operator, Installation CR,
and CRDs under TF requires dedicated prep (picking the right
`ignore_changes` fields to absorb operator-generated defaults in the
Installation CR, decoupling from the embedded PSA labels applied at
admission, and a low-traffic window). Deferred to `code-3ad`.
## This change
New Tier 1 stack `stacks/calico/` adopting via import `{}` blocks
(Wave 8 convention, commit 8a99be11):
- `kubernetes_namespace.calico_system` ← id `calico-system`
- `kubernetes_namespace.calico_apiserver` ← id `calico-apiserver`
- `kubernetes_namespace.tigera_operator` ← id `tigera-operator`
Apply: `3 imported, 0 added, 0 changed, 0 destroyed.` Followed by a
second `tg plan` that returns `No changes`. Zero cluster impact —
namespaces stayed exactly as they were cluster-side.
### terragrunt dependency choice
Deliberately no `dependency "platform"` clause — Calico is lower in the
stack than platform, so introducing a `platform → calico` or
`calico → platform` edge would invite cycle-like pain on first
bootstrap. The plan on this stack is always safe to run standalone.
### `ignore_changes` scope on each namespace
- `goldilocks.fairwinds.com/vpa-update-mode` — Kyverno ClusterPolicy
stamp (Wave 3B sweep, commit 8b43692a).
- `pod-security.kubernetes.io/enforce` + `-version` — tigera-operator
stamps these on `calico-system` + `calico-apiserver` to opt them out
of PSA. These labels aren't surfaced by the kubernetes provider as
part of the import (they arrive through a different field manager),
so left unmanaged to keep the plan clean. `tigera-operator` ns
doesn't get the PSA labels so they aren't ignored there.
## What is NOT in this change
- The three live workloads: `tigera-operator` Deployment in
`tigera-operator` ns, `calico-kube-controllers`/`calico-node`/
`calico-typha` workloads in `calico-system`, the `calico-apiserver`
in `calico-apiserver`. These are all reconciled by the tigera-operator
from the Installation CR — importing them into TF is redundant with
importing the CR itself.
- The `Installation` CR (`default`, apiVersion
`operator.tigera.io/v1`) — the user-authored minimal spec has since
been filled to 104 lines of operator-generated defaults. Adopting it
requires a well-scoped `ignore_changes` list on the `manifest` field.
Separate follow-up `code-3ad`.
- `.sops.yaml` / `tier0_stacks` updates — the original plan suggested
Tier 0 (local SOPS state) for the full Calico stack on the theory
that "network underpins all". With only three namespaces in the stack,
the argument doesn't hold: a failed Tier 1 plan on calico namespaces
cannot break networking, so no need to pay the Tier 0 tax.
## Verification
```
$ cd stacks/calico && ../../scripts/tg plan
No changes. Your infrastructure matches the configuration.
$ kubectl get pods -n calico-system
NAME READY STATUS RESTARTS
calico-kube-controllers-... 1/1 Running 0
calico-node-... 1/1 Running 0
... (all healthy, pre-existing)
```
Follow-up: code-3ad for operator + Installation CR adoption (needs
low-traffic window + ignore_changes scoping).
Closes: code-hl1 scope of Wave 5b (namespaces). Remaining subwave in code-3ad.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-04-18 22:52:56 +00:00
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