Sticky Cookie Sessions

General Discussions
22

Ok so the first error I received was that the resolver directive cannot be used in the upstream block. So I moved the resolver directive to the server block. Now the error is:
nginx: [emerg] host not found in upstream "tasks.multiuser:80"
Here are the container names:
e04c9981fe09 mydockerstack_multiuser.1.wos8rexum9u4m4r4cel6cqr0z
fca252d19039 mydockerstack_multiuser.2.imz29xw17tccnok8ob3c04abv

23

Hmm, according nginx documentation upstream allows the resolver directive, see: Module ngx_http_upstream_module

Though, I must admit, I never used it there, as I never had the need to implement sticky sessions in nginx.

Hmm, the external network ${DOCKER_NETWORK_NAME} is of type overlay, right? In my tests it works with tasks.${servicename} and tasks.${servicename}.${networkname} with deploy mode replicated and global - both variants return dnsrr ips of the containersā€¦ Not sure if this is because the resolver didnā€™t work in the upstream block.

The container names donā€™t matter for that issue.

24

Ok thanks! Ya, network is overlay, and I will try tasks.${servicename}.${networkname} with my stack deploy!

25

Like is said the ${networkname} shouldnā€™t matter and additionaly it introduces a maintainance mess, as you would always need to modify the configuration in case a different network name is used.

The service name must literaly match the name of the service declared in the compose file. The same usualy is true for the network, but I have no idea if this still applies when default points to an external network with different name - even though inside the compose file a serviceā€™s network declaration needs default, I would expect it to use the external networks name from inside the container.

Btw. you can drop the :80 on the upstream server directive.

26

Sounds good! Also, I moved the network creation into the docker-compose file.
networks:
net:
driver: overlay
attachable: true
and added networks: net to each service

27

Ok, here is my my nginx default.conf file:

upstream besoshub {
    ip_hash;

    server tasks.multiuser;

}

server {

    listen 80;
    server_name example.com;  # Real domain hidden

    # set DNS resolver as Docker internal DNS
    resolver 127.0.0.11 valid=10s;
    resolver_timeout 5s;

    location / {
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header Host $host;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

        # websocket headers
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        #proxy_set_header Connection $connection_upgrade;
        proxy_set_header X-Scheme $scheme;

        proxy_buffering off;

        set $target http://besoshub;
        proxy_pass $target;
    }
}

With 2 multiuser replicas, I get the following error after GitLab redirects back to my server after authenticating:

400: Bad Request
OAuth state missing from cookies

So possibly the ip_hash directive is not working to enable sticky sessions.
Thanks again for all your help and super quick responses!!!

28

I bet it has something to do with my nginx only listening on port 80 and not 443 haha! I will set that up now!