slaprunner: make sure custom frontend-url is published

software/slaprunner/buildout.hash.cfg

@@ -18,7 +18,7 @@ md5sum = 713db528880282d568278f09458d2aab
 
 [template-runner]
 filename = instance-runner.cfg
-md5sum = cefbc8abef234c9a74f88688a0ac0030
+md5sum = e12255a8c946b3eb8c6373fff481339f
 
 [template-runner-import-script]
 filename = template/runner-import.sh.jinja2

software/slaprunner/instance-runner.cfg

@@ -86,8 +86,24 @@ check-secure = 1
 dash_path = {{ dash_executable_location }}
 curl_path = {{ curl_executable_location }}
 
+[custom-frontend-url-ready-promise]
+recipe = slapos.recipe.template:jinja2
+path = $${directory:promises}/custom_frontend_ready_promise
+url = https://$${request-custom-frontend:connection-domain}
+rendered = $${directory:promises}/custom_frontend_ready_promise
+template = inline:
+  #!{{ dash_executable_location }}
+
+  URL="$${:url}"
+  CODE=$({{ curl_executable_location }} -g -k -sL $URL -w %{http_code} --max-time 5 -o /dev/null)
+
+  if [ $? -eq 3 ]; then
+    echo "Custom frontend URL malformed: $URL." >&2
+    exit 1
+  fi
+
 [publish-connection-information]
-custom-frontend-url = https://$${request-custom-frontend:connection-domain}
+custom-frontend-url = $${custom-frontend-url-ready-promise:url}
 {% endif %}
 
 # Create all needed directories