We have 2 app engine app (flex and standard) running on separate projects and we want project A to request project B with https to xxx.appspot.com
URL.
Our firewall on both projects Denies all IPs(*) and whitelisted App Engine internal addresss (10.1.0.41, 0.1.0.40, 10.0.0.1 and 0.1.0.30) as explained in the doc.
Yet we receive a "403 error forbidden access" (which disappears when disabling the firewall).
This post is similar to mine but the responses didn't help me.
Is there anything else I can do ? Did anyone got this to work ?
Thank you in advance.