Trying to run Jenkins behind SSL reverse proxy - 404 http://localhost/jenkins/manage vs. https:

I am trying to run Jenkins behind nginx. Jenkins runs in a Docker container, listening on Port 8080 from directory /jenkins. My nginx container has this Jenkins container linked as hostname "jenkins", so in its context, Jenkins is accessible via http://jenkins:8080/jenkins.

I followed the steps at Running Jenkins from a folder with TLS encryption and thus my site-config contains this:

location ^~ /jenkins/ { sendfile off; proxy_set_header Host $host; proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_pass http://jenkins:8080/jenkins/; proxy_redirect http:// https://; proxy_max_temp_file_size 0; client_max_body_size 64m; client_body_buffer_size 128k; proxy_connect_timeout 90; proxy_send_timeout 90; proxy_read_timeout 90; proxy_buffer_size 4k; proxy_buffers 4 32k; proxy_busy_buffers_size 64k; proxy_temp_file_write_size 64k; } 

I am now trying to access the nginx from localhost, and calling https://localhost/jenkins presents me Jenkins. However, when I go to "Manage Jenkins", I get the message that my reverse proxy setup is incorrect. I tried

curl -k -iL -e https://localhost/jenkins/manage \ https://localhost/jenkins/administrativeMonitor/hudson.diagnosis.ReverseProxySetupMonitor/test 

which gives me a 404 with http://localhost/jenkins/manage vs. https:.

When I add

 proxy_set_header X-Forwarded-Proto https; proxy_set_header X-Forwarded-Port 443; proxy_set_header X-Forwarded-Ssl on; 

the message changes to https://localhost/jenkins/manage vs. https:

What am I missing?