Add health checks for Docker services, ACME environment readiness validation, and Certbot unit tests

- Introduced health checks to Docker Compose files for better service reliability.
- Added ACME environment readiness validation to ensure proper configuration for Certbot.
- Implemented unit tests for Certbot's `check_acme_environment_ready` method to cover edge cases.
- Improved E2E tests with startup wait adjustments and dynamic certificate issuance verification.
- Enhanced Kubernetes test cleanup with forced resource deletion for faster termination.

tests_e2e/docker/docker-compose-acme-e2e.yml

@@ -64,6 +64,22 @@ services:
     networks:
       - acme-test
 
+  # Pebble health check sidecar
+  pebble_health:
+    image: curlimages/curl:8.6.0
+    depends_on:
+      - pebble
+    healthcheck:
+      test: ["CMD", "curl", "-skf", "https://pebble:14000/dir"]
+      interval: 5s
+      timeout: 3s
+      start_period: 5s
+      retries: 3
+    networks:
+      - acme-test
+    restart: "no"
+    command: ["tail", "-f", "/dev/null"]
+
   # Backend web server
   backend:
     image: byjg/static-httpserver
@@ -82,8 +98,16 @@ services:
       context: ../..
       dockerfile: build/Dockerfile
     depends_on:
-      - pebble
-      - backend
+      pebble_health:
+        condition: service_healthy
+      backend:
+        condition: service_started
+    healthcheck:
+      test: ["CMD", "curl", "-f", "-u", "admin:password", "http://localhost:1936"]
+      interval: 10s
+      timeout: 5s
+      start_period: 30s
+      retries: 3
     environment:
       EASYHAPROXY_DISCOVER: docker
       HAPROXY_CUSTOMERRORS: "true"