Recipe 2 — Apply your first WAFPolicy: CR plus one curl, the verdict line

Tool	Section	Level	Time	Layer	Tags
lab/dx1/apply-effect.sh	Getting started	easy	2 min after Recipe 1	policy + engine	policy, WAFPolicy, CEL, verdict

Problem

You have the lab from Recipe 1. You want one WAFPolicy CR to gate one route. You want the verdict line on the response. You want the same verdict in the engine log. You want the transparent requests to still pass.

Solution

The lab stays up from Recipe 1. You need kubectl and curl.

1. Run the apply→effect leg. The leg applies the CRD and the lab policy. The leg times the apply→effect round trip. The leg then runs the fail-closed scenario:

bash lab/dx1/apply-effect.sh

2. Read the printed evidence. The shapes below carry placeholders:

== pre-policy baseline: the benign probe passes transparently (200)
== (b) t0 — kubectl apply dx1-wafpolicy.yaml
== effect: SQLi probe → 403
HTTP/1.1 403 Forbidden
== M9 apply→effect: <ms> (target ≤ 5s) — PASS
== fail-closed scenario: <ms> from apply(broken) to the logged compile error; traffic unchanged; pods Ready

3. Gate one probe with one curl. The shapes below come from the recorded run. Volatile fields stand as placeholders:

NODE_IP=$(kubectl get nodes -o go-template --template '{{range .items}}{{range .status.addresses}}{{if eq .type "InternalIP"}}{{.address}} {{end}}{{end}}{{end}}' | awk '{print $1}')
curl -s -i -X POST "http://${NODE_IP}:31437/v1/chat/completions?q=UNION%20SELECT%2F%2A" \
  -H "Host: dx1-routed.dx1.example.com"

The blocked probe answers 403 and carries the verdict line:

HTTP/1.1 403 Forbidden
X-Trishula-Decision: block
X-Trishula-Hop: engine
X-Trishula-Rule: DX-LAB-001

blocked by DX-LAB-001

4. Check the benign request. The default action keeps the transparent forward:

curl -s -i -X POST "http://${NODE_IP}:31437/v1/chat/completions?q=greeting" \
  -H "Host: dx1-routed.dx1.example.com"

HTTP/1.1 200 OK
X-Trishula-Decision: pass
X-Trishula-Hop: engine

Discussion

The policy CR declares defaultAction: pass and one rule set. The rule set points at the rule pack. The pack sits in a ConfigMap (dx1-sqli) in the policy namespace. The pack carries one CEL rule:

request.method == "POST" &&
path.matches("/v1/chat/*") &&
request.query.contains("UNION")

The operator compiles the rule into the bundle. The engine picks up the bundle. No restart happens. The response carries the verdict vocabulary: pass and block. The blocked response names the rule id. The engine log carries the same verdict line:

engine: decision block (rule=DX-LAB-001) for POST /v1/chat/completions

The apply→effect leg carries the 5 s M9 budget. The gate fails above the budget. A broken policy fails at compile. No bundle ships. The traffic shape does not change. Both pods stay Ready. A bad CR keeps the last good decisions. That is the fail-closed posture.

See also

• spec 11.3 — the CEL rule surface.
• The WAFPolicy CRD · The lab policy · The rule pack.
• TR-08c issue #76 — the apply→effect gate.
• The DX1 lab README — the three steps and the knobs.
• Recipe 1 — the install path.

Provenance

Verified against trishula@10df4bee on main, 2026-10-25.

Smoke run, 2026-10-25, on the OrbStack-provided Kubernetes provider with NGF 1.6.2:

• lab/dx1/apply-effect.sh: exit 0. The M9 leg read 1860 ms. The fail-closed leg read 1009 ms.
• The verdict curls: the benign POST read 200 with X-Trishula-Decision: pass. The SQLi probe read 403 with X-Trishula-Decision: block and X-Trishula-Rule: DX-LAB-001.
• The engine log carried the same decision line.