Allow dedicated Redis for OCSP publication

docker-compose.yml

@@ -105,7 +105,9 @@ services:
       OTEL_EXPORTER_OTLP_ENDPOINT: ${OTEL_EXPORTER_OTLP_ENDPOINT:-}
       OTEL_EXPORTER_OTLP_HEADERS: ${OTEL_EXPORTER_OTLP_HEADERS:-}
       OTEL_EXCLUDED_PATHS: ${OTEL_EXCLUDED_PATHS:-/api/health}
-      # OCSP snapshots use the same Redis instance as sessions, under ocsp:*.
+      # OCSP snapshots default to the session Redis. Set KCA_OCSP_REDIS_URL to
+      # use a dedicated instance instead.
+      KCA_OCSP_REDIS_URL: ${KCA_OCSP_REDIS_URL:-}
       KCA_OCSP_REDIS_PREFIX: ${KCA_OCSP_REDIS_PREFIX:-ocsp}
       KCA_OCSP_PUBLISH_INTERVAL_SECONDS: ${KCA_OCSP_PUBLISH_INTERVAL_SECONDS:-1}
       KCA_OCSP_HEARTBEAT_INTERVAL_SECONDS: ${KCA_OCSP_HEARTBEAT_INTERVAL_SECONDS:-30}
@@ -114,7 +116,8 @@ services:
       - "127.0.0.1:${APP_PORT:-8080}:8080"
 
   # Optional standalone OCSP responder. It has no database or KCA master-key
-  # environment, but reads OCSP keys from the same Redis instance as sessions.
+  # environment, but reads OCSP keys from the configured Redis (the session
+  # Redis by default).
   # Enable with:
   #   docker compose --profile ocsp up --build
   ocsp: