Create route and domain method for creating a subscription

atst/routes/applications/settings.py

@@ -1,9 +1,10 @@
 from flask import (
+    current_app as app,
+    g,
     redirect,
     render_template,
     request as http_request,
     url_for,
-    g,
 )
 
 from .blueprint import applications_bp
@@ -522,3 +523,31 @@ def resend_invite(application_id, application_role_id):
             _anchor="application-members",
         )
     )
+
+
+@applications_bp.route(
+    "/environments/<environment_id>/add_subscription", methods=["POST"]
+)
+# TODO: decide what perms are needed to create a subscription
+@user_can(Permissions.EDIT_ENVIRONMENT, message="create new environment subscription")
+def create_subscription(environment_id):
+    environment = Environments.get(environment_id)
+
+    try:
+        app.csp.cloud.create_subscription(environment)
+
+    except GeneralCSPException:
+        flash("environment_subscription_failure")
+        return (
+            render_settings_page(application=environment.application, show_flash=True),
+            400,
+        )
+
+    return redirect(
+        url_for(
+            "applications.settings",
+            application_id=environment.application.id,
+            fragment="application-environments",
+            _anchor="application-environments",
+        )
+    )