caddy-frontend: Protect against malformed backend from the request

The backend url can come from request in `url` and `https-url` strings.
It is validated using real caddy template configuration and by using
caddy's `-stdin`. It results with calling it on each slave having any of
those parameters.

software/caddy-frontend/TODO.rst

@@ -2,6 +2,7 @@ Generally things to be done with ``caddy-frontend``:
 
  * tests: add assertion with results of promises in etc/promise for each partition
  * generated files: ``| trim`` values (like ``slave_password[slave]`` in ``templates/template-log-access.conf.in``) in generated configuration files to have them renfered correctly
+ * check the whole frontend slave snippet with ``caddy -validate`` during buildout run, and reject if does not pass validation
  * ``apache-ca-certificate`` shall be merged with ``apache-certificate``
 
    * ``apache-ca-certificate`` shall be appended to ``apache-certificate`` if not already there

software/caddy-frontend/buildout.hash.cfg

@@ -14,7 +14,7 @@
 # not need these here).
 [template]
 filename = instance.cfg
-md5sum = 906e5bd66b1265b8109a86b6ab46e91f
+md5sum = b73505ae80d6325a244f5094f8edc0ae
 
 [template-apache-frontend]
 filename = instance-apache-frontend.cfg
@@ -22,7 +22,7 @@ md5sum = b170d0987563b481eb71cf705c3658ab
 
 [template-apache-replicate]
 filename = instance-apache-replicate.cfg.in
-md5sum = 7f15b5745eda8e1f02d4bf7d886dcdad
+md5sum = 27e98547061bd81e5f84cb7dd21b683b
 
 [template-slave-list]
 filename = templates/apache-custom-slave-list.cfg.in
@@ -44,6 +44,10 @@ md5sum = 6689d96fc18d9aad78d77fe87770d4da
 filename = templates/apache-custom-slave-list.cfg.in
 md5sum = fb6c93f42f232e381174a5951c3fc222
 
+[caddy-backend-url-validator]
+filename = templates/caddy-backend-url-validator.in
+md5sum = 0979a03476e86bf038516c9565dadc17
+
 [template-not-found-html]
 filename = templates/notfound.html
 md5sum = f20d6c3d2d94fb685f8d26dfca1e822b

software/caddy-frontend/common.cfg

@@ -46,6 +46,13 @@ url = ${:_profile_base_location_}/instance-apache-frontend.cfg
 output = ${buildout:directory}/template-caddy-frontend.cfg
 mode = 0644
 
+[caddy-backend-url-validator]
+recipe = slapos.recipe.template
+url = ${:_profile_base_location_}/templates/${:filename}
+filename = caddy-backend-url-validator.in
+output = ${buildout:directory}/caddy-backend-url-validator
+mode = 0750
+
 [template-caddy-replicate]
 recipe = slapos.recipe.build:download
 url = ${:_profile_base_location_}/instance-apache-replicate.cfg.in

software/caddy-frontend/instance-apache-replicate.cfg.in

@@ -72,10 +72,25 @@ context =
 {% for slave in slave_instance_list %}
 {# BBB: apache_custom_https AND apache_custom_http #}
 {%   if not ((slave.has_key('caddy_custom_http') or slave.has_key('apache_custom_http') or slave.has_key('caddy_custom_https') or slave.has_key('apache_custom_https')) and not slave.get('slave_reference') in authorized_slave_string) %}
+{%     set slave_ok = True %}
+{%     if slave.get('url') %}
+{%       if subprocess_module.call([caddy_backend_url_validator, slave['url']]) == 1 %}
+{%         set slave_ok = False %}
+{%       endif %}
+{%     endif %}
+{%     if slave.get('https-url') %}
+{%       if subprocess_module.call([caddy_backend_url_validator, slave['https-url']]) == 1 %}
+{%         set slave_ok = False %}
+{%       endif %}
+{%     endif %}
+{%     if slave_ok %}
 {%       do authorized_slave_list.append(slave) %}
 {%     else %}
 {%       do rejected_slave_list.append(slave.get('slave_reference')) %}
 {%     endif %}
+{%   else %}
+{%     do rejected_slave_list.append(slave.get('slave_reference')) %}
+{%   endif %}
 {% endfor %}
 
 [monitor-instance-parameter]

software/caddy-frontend/instance.cfg

@@ -43,6 +43,8 @@ template = ${template-caddy-replicate:target}
 filename = instance-caddy-replicate.cfg
 extensions = jinja2.ext.do
 extra-context =
+    import subprocess_module subprocess
+    raw caddy_backend_url_validator ${caddy-backend-url-validator:output}
     raw template_publish_slave_information ${template-replicate-publish-slave-information:target}
 # Must match the key id in [switch-softwaretype] which uses this section.
     raw software_type RootSoftwareInstance-default-custom-personal-replicate

software/caddy-frontend/templates/caddy-backend-url-validator.in

+#!${dash:location}/bin/dash
+config="https://example.com {\n  proxy / $1 {\n  }\n}"
+
+echo -e $config | ${caddy:output} -conf stdin -validate > /dev/null 2>&1

software/caddy-frontend/test/test.py

@@ -2692,3 +2692,91 @@ class TestRe6stVerificationUrlSlave(SlaveHttpFrontendTestCase,
       'URL="some-re6st-verification-url"' in
       open(re6st_connectivity_promise_list[0]).read()
     )
+
+
+class TestMalformedBackenUrlSlave(SlaveHttpFrontendTestCase,
+                                  TestDataMixin):
+  @classmethod
+  def getInstanceParameterDict(cls):
+    return {
+      'domain': 'example.com',
+      'nginx-domain': 'nginx.example.com',
+      'public-ipv4': utils.LOCAL_IPV4,
+      'apache-certificate': open('wildcard.example.com.crt').read(),
+      'apache-key': open('wildcard.example.com.key').read(),
+      'port': HTTPS_PORT,
+      'plain_http_port': HTTP_PORT,
+      'nginx_port': NGINX_HTTPS_PORT,
+      'plain_nginx_port': NGINX_HTTP_PORT,
+      'monitor-httpd-port': MONITOR_HTTPD_PORT,
+      '-frontend-config-1-monitor-httpd-port': MONITOR_F1_HTTPD_PORT,
+    }
+
+  @classmethod
+  def getSlaveParameterDictDict(cls):
+    return {
+      'empty': {
+      },
+      'url': {
+        'url': "https://[fd46::c2ae]:!py!u'123123'",
+      },
+      'https-url': {
+        'https-url': "https://[fd46::c2ae]:!py!u'123123'",
+      }
+    }
+
+  def test_master_partition_state(self):
+    parameter_dict = self.computer_partition.getConnectionParameterDict()
+    self.assertKeyWithPop('monitor-setup-url', parameter_dict)
+
+    expected_parameter_dict = {
+      'monitor-base-url': None,
+      'domain': 'example.com',
+      'accepted-slave-amount': '1',
+      'rejected-slave-amount': '2',
+      'slave-amount': '3',
+      'rejected-slave-list': '["_url", "_https-url"]'}
+
+    self.assertEqual(
+      expected_parameter_dict,
+      parameter_dict
+    )
+
+  def test_empty(self):
+    parameter_dict = self.slave_connection_parameter_dict_dict[
+      'empty']
+    self.assertLogAccessUrlWithPop(parameter_dict, 'empty')
+    self.assertEqual(
+      parameter_dict,
+      {
+        'domain': 'empty.example.com',
+        'replication_number': '1',
+        'url': 'http://empty.example.com',
+        'site_url': 'http://empty.example.com',
+        'secure_access': 'https://empty.example.com',
+        'public-ipv4': utils.LOCAL_IPV4,
+      }
+    )
+
+    result = self.fakeHTTPSResult(
+      parameter_dict['domain'], parameter_dict['public-ipv4'], 'test-path')
+
+    self.assertEqual(
+      utils.der2pem(result.peercert),
+      open('wildcard.example.com.crt').read())
+
+    self.assertEqual(result.status_code, no_backend_response_code)
+
+  def test_url(self):
+    parameter_dict = self.slave_connection_parameter_dict_dict[
+      'url'].copy()
+    self.assertEqual(
+      parameter_dict, {}
+    )
+
+  def test_https_url(self):
+    parameter_dict = self.slave_connection_parameter_dict_dict[
+      'https-url'].copy()
+    self.assertEqual(
+      parameter_dict, {}
+    )

software/caddy-frontend/test/test_data/test.TestMalformedBackenUrlSlave.test_file_list_log-CADDY.txt

+TestMalformedBackenUrlSlave-0/var/log/monitor-httpd-error.log
+TestMalformedBackenUrlSlave-1/var/log/frontend-access.log
+TestMalformedBackenUrlSlave-1/var/log/frontend-error.log
+TestMalformedBackenUrlSlave-1/var/log/httpd/_empty_access_log
+TestMalformedBackenUrlSlave-1/var/log/httpd/_empty_error_log
+TestMalformedBackenUrlSlave-1/var/log/monitor-httpd-error.log
+TestMalformedBackenUrlSlave-1/var/log/nginx-access.log
+TestMalformedBackenUrlSlave-1/var/log/nginx-error.log
+TestMalformedBackenUrlSlave-1/var/log/trafficserver/manager.log
+TestMalformedBackenUrlSlave-1/var/log/trafficserver/traffic.out
\ No newline at end of file

software/caddy-frontend/test/test_data/test.TestMalformedBackenUrlSlave.test_file_list_run-CADDY.txt

+TestMalformedBackenUrlSlave-0/var/run/monitor-httpd.pid
+TestMalformedBackenUrlSlave-0/var/run/monitor/monitor-bootstrap.pid
+TestMalformedBackenUrlSlave-1/var/run/caddy_configuration.signature
+TestMalformedBackenUrlSlave-1/var/run/httpd.pid
+TestMalformedBackenUrlSlave-1/var/run/monitor-httpd.pid
+TestMalformedBackenUrlSlave-1/var/run/monitor/monitor-bootstrap.pid
+TestMalformedBackenUrlSlave-1/var/run/ncaddy_configuration.signature
+TestMalformedBackenUrlSlave-1/var/run/nginx.pid

software/caddy-frontend/test/test_data/test.TestMalformedBackenUrlSlave.test_monitor_promise_list-CADDY.txt

+TestMalformedBackenUrlSlave-1/etc/monitor-promise/check-_empty-error-log-last-day
+TestMalformedBackenUrlSlave-1/etc/monitor-promise/check-_empty-error-log-last-hour
\ No newline at end of file

software/caddy-frontend/test/test_data/test.TestMalformedBackenUrlSlave.test_promise_list-CADDY.txt

+TestMalformedBackenUrlSlave-0/etc/promise/check-free-disk-space
+TestMalformedBackenUrlSlave-0/etc/promise/monitor-http-frontend
+TestMalformedBackenUrlSlave-0/etc/promise/monitor-httpd-listening-on-tcp
+TestMalformedBackenUrlSlave-0/etc/promise/promise-monitor-httpd-is-process-older-than-dependency-set
+TestMalformedBackenUrlSlave-1/etc/promise/caddy-frontend-is-running-actual-software-release
+TestMalformedBackenUrlSlave-1/etc/promise/caddy_cached
+TestMalformedBackenUrlSlave-1/etc/promise/caddy_frontend_ipv4_http
+TestMalformedBackenUrlSlave-1/etc/promise/caddy_frontend_ipv4_https
+TestMalformedBackenUrlSlave-1/etc/promise/caddy_frontend_ipv6_http
+TestMalformedBackenUrlSlave-1/etc/promise/caddy_frontend_ipv6_https
+TestMalformedBackenUrlSlave-1/etc/promise/caddy_ssl_cached
+TestMalformedBackenUrlSlave-1/etc/promise/check-free-disk-space
+TestMalformedBackenUrlSlave-1/etc/promise/frontend-caddy-configuration-promise
+TestMalformedBackenUrlSlave-1/etc/promise/monitor-http-frontend
+TestMalformedBackenUrlSlave-1/etc/promise/monitor-httpd-listening-on-tcp
+TestMalformedBackenUrlSlave-1/etc/promise/nginx-configuration-promise
+TestMalformedBackenUrlSlave-1/etc/promise/nginx_frontend_ipv4_http
+TestMalformedBackenUrlSlave-1/etc/promise/nginx_frontend_ipv4_https
+TestMalformedBackenUrlSlave-1/etc/promise/nginx_frontend_ipv6_http
+TestMalformedBackenUrlSlave-1/etc/promise/nginx_frontend_ipv6_https
+TestMalformedBackenUrlSlave-1/etc/promise/promise-monitor-httpd-is-process-older-than-dependency-set
+TestMalformedBackenUrlSlave-1/etc/promise/promise-nginx-is-process-older-than-dependency-set
+TestMalformedBackenUrlSlave-1/etc/promise/re6st-connectivity
+TestMalformedBackenUrlSlave-1/etc/promise/trafficserver-cache-availability
+TestMalformedBackenUrlSlave-1/etc/promise/trafficserver-port-listening
\ No newline at end of file

software/caddy-frontend/test/test_data/test.TestMalformedBackenUrlSlave.test_supervisor_state-CADDY.txt

+TestMalformedBackenUrlSlave-0:bootstrap-monitor EXITED
+TestMalformedBackenUrlSlave-0:certificate_authority-on-watch RUNNING
+TestMalformedBackenUrlSlave-0:crond RUNNING
+TestMalformedBackenUrlSlave-0:monitor-httpd-graceful EXITED
+TestMalformedBackenUrlSlave-0:monitor-httpd-on-watch RUNNING
+TestMalformedBackenUrlSlave-1:6tunnel-11080-on-watch RUNNING
+TestMalformedBackenUrlSlave-1:6tunnel-11443-on-watch RUNNING
+TestMalformedBackenUrlSlave-1:6tunnel-12080-on-watch RUNNING
+TestMalformedBackenUrlSlave-1:6tunnel-12443-on-watch RUNNING
+TestMalformedBackenUrlSlave-1:6tunnel-26011-on-watch RUNNING
+TestMalformedBackenUrlSlave-1:6tunnel-26012-on-watch RUNNING
+TestMalformedBackenUrlSlave-1:bootstrap-monitor EXITED
+TestMalformedBackenUrlSlave-1:certificate_authority-on-watch RUNNING
+TestMalformedBackenUrlSlave-1:crond-on-watch RUNNING
+TestMalformedBackenUrlSlave-1:frontend-caddy-safe-graceful EXITED
+TestMalformedBackenUrlSlave-1:frontend-nginx-safe-graceful EXITED
+TestMalformedBackenUrlSlave-1:frontend_caddy-on-watch RUNNING
+TestMalformedBackenUrlSlave-1:frontend_nginx-on-watch RUNNING
+TestMalformedBackenUrlSlave-1:monitor-httpd-graceful EXITED
+TestMalformedBackenUrlSlave-1:monitor-httpd-on-watch RUNNING
+TestMalformedBackenUrlSlave-1:trafficserver-on-watch RUNNING
+TestMalformedBackenUrlSlave-1:trafficserver-reload EXITED
+watchdog:watchdog RUNNING