I am using nginx to map multiple domains to google app engine. in this specific case i map multiple domains to the same tenant. there is a configuration in my code that knows which domain is the main domain and when a request comes in i check if the host is the main domain and if it isn't i redirect to the main domain.
for example lets say www.aaa.com is the domain set as default
aaa.com -> www.aaa.com www.bbb.com -> www.aaa.com ccc.com -> www.aaa.com ... what happens randomly from time to time is that a javascript url goes into a redirect loop on nginx. note that the request never hits appengine. nginx is creating this 302 Found loop. this happened 2 times in the past 2 weeks.
the request path looks like www.aaa.com/22/foobar.js where the first part of the path is the version number of the javascript file.
a css file with the same uri format www.aaa.com/22/foobar.css won't have this redirect loop.
if i deploy a new version the file will server correctly again. so deploying a version 23 and accessing www.aaa.com/23/foobar.js would work again. also if i use a cachebuster on the request like www.aaa.com/22/foobar.js?345 restarting nginx or even restarting the machine where nginx is running does not help. setting up a new machine with the same exact configuration serves the file with no problem.
so what could cause this redirect loop? how could i get rid of it once it happens? is there a cache on nginx (i know nginx is not caching by default) i dont know about? does the machine maybe cache those redirects?
here my nginx.conf
user nginx; worker_processes 2; error_log /var/log/nginx/error.log; pid /var/run/nginx.pid; events { worker_connections 1024; } http { include /etc/nginx/mime.types; default_type application/octet-stream; server_names_hash_max_size 1024; server_names_hash_bucket_size 128; log_format main '$remote_addr - $remote_user [$time_local] "$request" ' '$status $body_bytes_sent "$http_referer" ' '"$http_user_agent" "$http_x_forwarded_for"'; access_log /var/log/nginx/access.log main; sendfile on; keepalive_timeout 65; # enable gzip compression gzip on; gzip_min_length 1100; gzip_buffers 4 32k; gzip_comp_level 5; gzip_types text/plain application/x-javascript text/xml text/css; gzip_vary on; server { server_name www.aaa.com; location / { resolver 8.8.8.8; proxy_pass http://tenantname.myappid.appspot.com/$request_uri; proxy_set_header Host tenantname.myappid.appspot.com; proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_set_header NexHost $scheme://$host; proxy_redirect http://tenantname.myappid.appspot.com/ /; proxy_intercept_errors on; } } server { server_name aaa.com; location / { resolver 8.8.8.8; proxy_pass http://tenantname.myappid.appspot.com/$request_uri; proxy_set_header Host tenantname.myappid.appspot.com; proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_set_header NexHost $scheme://$host; proxy_redirect http://tenantname.myappid.appspot.com/ /; proxy_intercept_errors on; } } server { server_name www.bbb.com; location / { resolver 8.8.8.8; proxy_pass http://tenantname.myappid.appspot.com/$request_uri; proxy_set_header Host tenantname.myappid.appspot.com; proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_set_header NexHost $scheme://$host; proxy_redirect http://tenantname.myappid.appspot.com/ /; proxy_intercept_errors on; } } server { server_name bbb.com; location / { resolver 8.8.8.8; proxy_pass http://tenantname.myappid.appspot.com/$request_uri; proxy_set_header Host tenantname.myappid.appspot.com; proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_set_header NexHost $scheme://$host; proxy_redirect http://tenantname.myappid.appspot.com/ /; proxy_intercept_errors on; } } server { server_name www.ccc.com; location / { resolver 8.8.8.8; proxy_pass http://tenantname.myappid.appspot.com/$request_uri; proxy_set_header Host tenantname.myappid.appspot.com; proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_set_header NexHost $scheme://$host; proxy_redirect http://tenantname.myappid.appspot.com/ /; proxy_intercept_errors on; } } server { server_name ccc.com; location / { resolver 8.8.8.8; proxy_pass http://tenantname.myappid.appspot.com/$request_uri; proxy_set_header Host tenantname.myappid.appspot.com; proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_set_header NexHost $scheme://$host; proxy_redirect http://tenantname.myappid.appspot.com/ /; proxy_intercept_errors on; } } server { server_name ~^(?<sub>.+)\.maindomain\.com$; location / { resolver 8.8.8.8; proxy_pass http://$sub.myappid.appspot.com/$request_uri; proxy_set_header Host $sub.myappid.appspot.com; proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_set_header NexHost $scheme://$host; proxy_redirect http://$sub.myappid.appspot.com/ /; proxy_intercept_errors on; } } server { listen 80 default_server; server_name _; location / { root /etc/nginx/html; } } } 