Application Load Balancer + Nginx http to https redirect gives 502 Bad Gateway

Question

What I try to do is very simple, I am using AWS application load balancer, and I want to redirect all my http requests to https: I have the following setup: An application load balancer (ALB1) which has two listeners:

HTTP:80
HTTP:443

Both rules are forwarding to a target group (TG1) in which 1 target instance is registered on both port 80 and 443, and both healthy.

and my nginx conf has the following setup:

server {
    listen 80;
    server_name {{server_name}};
    access_log /var/log/nginx/http_redirect.log;
    return 301 https://$server_name$request_uri;
}

server {
    server_name {{server_name}};
    listen 443 ssl default_server;
    ...
    ...
}

However, when I go to http://server_name/ping, I expect it to be redirected to https://server_name/ping, but I just got a 502 Bad Gateway, and I checked the log /var/log/nginx/http_redirect.log, it shows something like:

172.xx.xx.xx - - [13/Oct/2017:22:31:13 -0700] "\x16\x03\x01\x00\xA5\x01\x00\x00\xA1\x03\x03|\xFE\xC1\x88\x9E\xC88\xF8\xCDLn\xBAV,\xCE\xAF\xAA\xF2\x9Axv\x16\xD0\xC2\xE6\xFBE\x95oi%\x01\x00\x00(\xC0+\xC0/\xC0#\xC0'\xC0\x09\xC0\x13\xC0,\xC00\xC0$\xC0(\xC0\x14\xC0" 400 181 "-" "-"

another strange thing is if I refresh the page again, it gives the result without being redirected, and then refresh again, I will get 502 Bbad Gateway again, basically, I will get 502 Bad Gateway and result without redirect alternately. FYI, there is nothing in my nginx error log.

More observation: when I get correct response without redirecting, $remote_addr shows the IP of my vpn, and when I get 502, $remote_addr show another different IP.

Could anyone help? Thanks

user2002692 user2002692 · Accepted Answer · 2017-10-14T08:04:08

I finally figured out what is wrong, the way I set up my application load balancer was not exactly right, I cant have only 1 target group (TG1) in which 1 target instance is registered on both port 80 and 443. I need to setup 2 different target groups, 1 registered with port 443 and another 1 registered with port 80.

Application Load Balancer + Nginx http to https redirect gives 502 Bad Gateway

1 Answers