feat(federation): Step-CA sidecar in federated compose [FED-M2-02] (#490)

infra/step-ca/dev-password.example

@@ -0,0 +1 @@
+dev-only-step-ca-password-do-not-use-in-production

infra/step-ca/init.sh

@@ -0,0 +1,60 @@
+#!/bin/sh
+# infra/step-ca/init.sh
+#
+# Idempotent first-boot initialiser for the Mosaic Federation CA.
+#
+# On the first run (no /home/step/config/ca.json present) this script:
+#   1. Initialises Step-CA with a JWK provisioner named "mosaic-fed".
+#   2. Writes the CA configuration to the persistent volume at /home/step.
+#
+# On subsequent runs (config already exists) this script skips init and
+# starts the CA directly.
+#
+# The provisioner name "mosaic-fed" is consumed by:
+#   apps/gateway/src/federation/ca.service.ts  (added in M2-04)
+#
+# Password source:
+#   Dev:  mounted from ./infra/step-ca/dev-password via bind mount.
+#   Prod: mounted from a Docker secret at /run/secrets/ca_password.
+#
+# OID template:
+#   infra/step-ca/templates/federation.tpl is copied into the CA config
+#   directory so the JWK provisioner can reference it.  The template
+#   skeleton is wired in M2-04 when the CA service lands the SAN-bearing
+#   CSR work.
+
+set -e
+
+CA_CONFIG="/home/step/config/ca.json"
+PASSWORD_FILE="/run/secrets/ca_password"
+
+if [ ! -f "${CA_CONFIG}" ]; then
+  echo "[step-ca init] First boot detected — initialising Mosaic Federation CA..."
+
+  step ca init \
+    --name "Mosaic Federation CA" \
+    --dns "localhost" \
+    --dns "step-ca" \
+    --address ":9000" \
+    --provisioner "mosaic-fed" \
+    --password-file "${PASSWORD_FILE}" \
+    --provisioner-password-file "${PASSWORD_FILE}" \
+    --no-db
+
+  echo "[step-ca init] CA initialised."
+
+  # Copy the X.509 template into the Step-CA config directory so the
+  # provisioner can reference it in M2-04.
+  if [ -f "/etc/step-ca-templates/federation.tpl" ]; then
+    mkdir -p /home/step/templates
+    cp /etc/step-ca-templates/federation.tpl /home/step/templates/federation.tpl
+    echo "[step-ca init] Federation X.509 template copied to /home/step/templates/."
+  fi
+
+  echo "[step-ca init] Startup complete."
+else
+  echo "[step-ca init] Config already exists — skipping init."
+fi
+
+echo "[step-ca init] Starting Step-CA on :9000..."
+exec step-ca /home/step/config/ca.json --password-file "${PASSWORD_FILE}"

infra/step-ca/templates/federation.tpl

@@ -0,0 +1,48 @@
+{
+  "subject": {{ toJson .Subject }},
+  "sans": {{ toJson .SANs }},
+
+  {{- /*
+    Mosaic Federation X.509 Certificate Template
+    ============================================
+    This template is used by the "mosaic-fed" JWK provisioner to sign
+    federation client certificates.
+
+    Custom OID extensions (per PRD §6):
+      1.3.6.1.4.1.99999.1  — mosaic.federation.grantId   (UUID string)
+      1.3.6.1.4.1.99999.2  — mosaic.federation.subjectUserId (UUID string)
+
+    TODO (M2-04): Wire actual OID extensions below once the CA service
+    (apps/gateway/src/federation/ca.service.ts) lands the SAN-bearing CSR
+    work and the template can be exercised end-to-end.
+
+    Step-CA template reference:
+      https://smallstep.com/docs/step-ca/templates
+
+    Expected final shape of the extensions block (placeholder — not yet
+    activated):
+
+    "extensions": [
+      {
+        "id": "1.3.6.1.4.1.99999.1",
+        "critical": false,
+        "value": {{ toJson (first .Token.mosaic_grant_id) }}
+      },
+      {
+        "id": "1.3.6.1.4.1.99999.2",
+        "critical": false,
+        "value": {{ toJson (first .Token.mosaic_subject_user_id) }}
+      }
+    ],
+
+    The provisioner must pass these values in the ACME/JWK token payload
+    (token claims `mosaic_grant_id` and `mosaic_subject_user_id`) when
+    submitting the CSR.  M2-04 owns that work.
+  */ -}}
+
+  "keyUsage": ["digitalSignature"],
+  "extKeyUsage": ["clientAuth"],
+  "basicConstraints": {
+    "isCA": false
+  }
+}