configure traefik http security headers

.gitignore

@@ -215,3 +215,4 @@ tags
 .idea/
 
 .pytest_cache/
+.vscode/

cookiecutter.json

@@ -1,6 +1,7 @@
 {
   "project_name": "My Awesome Project",
   "project_slug": "{{ cookiecutter.project_name.lower()|replace(' ', '_')|replace('-', '_')|replace('.', '_')|trim() }}",
+  "_extensions": ["cookiecutter.extensions.RandomStringExtension"],
   "description": "Behold My Awesome Project!",
   "author_name": "Daniel Roy Greenfeld",
   "domain_name": "example.com",

{{cookiecutter.project_slug}}/compose/production/traefik/traefik.yml

@@ -1,3 +1,4 @@
+---
 log:
   level: INFO
 
@@ -30,6 +31,20 @@ certificatesResolvers:
       httpChallenge:
         entryPoint: web
 
+tls:
+  # https://docs.traefik.io/https/tls/#tls-options
+  options:
+    default:
+      # see https://caniuse.com/tls1-2 for browsers that support TLS 1.2
+      minVersion: VersionTLS12
+      # see https://caniuse.com/sni for browsers that support SNI
+      sniStrict: true
+      # https://wiki.mozilla.org/Security/Server_Side_TLS
+      cipherSuites: # use only elliptic curve (the strongest) ciphers
+        - TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
+        - TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
+        - TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
+
 http:
   routers:
     web-secure-router:
@@ -42,6 +57,7 @@ http:
         - web-secure
       middlewares:
         - csrf
+        - security-headers
       service: django
       tls:
         # https://docs.traefik.io/master/routing/routers/#certresolver
@@ -52,6 +68,8 @@ http:
       rule: "Host(`{{ cookiecutter.domain_name }}`)"
       entryPoints:
         - flower
+      middlewares:
+        - security-headers
       service: flower
       tls:
         # https://docs.traefik.io/master/routing/routers/#certresolver
@@ -64,6 +82,19 @@ http:
       # https://docs.djangoproject.com/en/dev/ref/csrf/#ajax
       headers:
         hostsProxyHeaders: ["X-CSRFToken"]
+    security-headers:
+      # https://docs.traefik.io/middlewares/headers/#general
+      headers:
+        # TODO increase stsSeconds to *at least* 31536000 (1 year) once HTTPS works
+        stsSeconds: 60
+        stsIncludeSubdomains: true
+        stsPreload: true
+        frameDeny: true
+        contentTypeNosniff: true
+        browserXssFilter: true
+        customResponseHeaders:
+          # https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Server
+          server: {{ random_ascii_string(10) }} # hide server version
 
   services:
     django:

{{cookiecutter.project_slug}}/config/settings/production.py

@@ -43,17 +43,14 @@ CACHES = {
 
 # SECURITY
 # ------------------------------------------------------------------------------
-# https://docs.djangoproject.com/en/dev/ref/settings/#secure-proxy-ssl-header
-SECURE_PROXY_SSL_HEADER = ("HTTP_X_FORWARDED_PROTO", "https")
+{%- if cookiecutter.use_docker -%}
+# NOTE headers are managed by the security-headers middleware in traefik.yml
+{%- else -%}
+# TODO set security headers in your load balancer if possible and remove these
 # https://docs.djangoproject.com/en/dev/ref/settings/#secure-ssl-redirect
 SECURE_SSL_REDIRECT = env.bool("DJANGO_SECURE_SSL_REDIRECT", default=True)
-# https://docs.djangoproject.com/en/dev/ref/settings/#session-cookie-secure
-SESSION_COOKIE_SECURE = True
-# https://docs.djangoproject.com/en/dev/ref/settings/#csrf-cookie-secure
-CSRF_COOKIE_SECURE = True
-# https://docs.djangoproject.com/en/dev/topics/security/#ssl-https
 # https://docs.djangoproject.com/en/dev/ref/settings/#secure-hsts-seconds
-# TODO: set this to 60 seconds first and then to 518400 once you prove the former works
+# TODO increase this to *at least* 31536000 (1 year) once HTTPS works
 SECURE_HSTS_SECONDS = 60
 # https://docs.djangoproject.com/en/dev/ref/settings/#secure-hsts-include-subdomains
 SECURE_HSTS_INCLUDE_SUBDOMAINS = env.bool(
@@ -65,6 +62,14 @@ SECURE_HSTS_PRELOAD = env.bool("DJANGO_SECURE_HSTS_PRELOAD", default=True)
 SECURE_CONTENT_TYPE_NOSNIFF = env.bool(
     "DJANGO_SECURE_CONTENT_TYPE_NOSNIFF", default=True
 )
+{%- endif -%}
+# https://docs.djangoproject.com/en/dev/topics/security/#ssl-https
+# https://docs.djangoproject.com/en/dev/ref/settings/#secure-proxy-ssl-header
+SECURE_PROXY_SSL_HEADER = ("HTTP_X_FORWARDED_PROTO", "https")
+# https://docs.djangoproject.com/en/dev/ref/settings/#session-cookie-secure
+SESSION_COOKIE_SECURE = True
+# https://docs.djangoproject.com/en/dev/ref/settings/#csrf-cookie-secure
+CSRF_COOKIE_SECURE = True
 
 {% if cookiecutter.cloud_provider != 'None' -%}
 # STORAGES