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A client is sending a custom HTTP Header X-ABC-LOGIN-NAME to my Nginx reverse proxy. To be sure that it is actually arriving, a PHP server (fastcgi) was installed and this header is really showing up (with a value) in phpinfo(), section 'PHP Variables'.

I operate a Django backend with a gunicorn server and in the Django code, I print all headers to the console. When I assign a static value to the X-ABC-LOGIN-NAME in /etc/nginx/sites-enabled/default, the value arrives at the backend. In the nginx default file this looks as:

server {
    listen      443 ssl http2 default_server;
    listen [::]:443 ssl http2 default_server;

    ssl_certificate /etc/nginx/ssl/nginx.crt;
    ssl_certificate_key /etc/nginx/ssl/nginx.key;
    ssl_protocols TLSv1 TLSv1.1 TLSv1.2;

    # include snippets/self-signed.conf;
    # include snippets/ssl-params.conf;
    # server_name   localhost;
    server_name dev_server;

    underscores_in_headers on;

    location / {
    
        proxy_pass http://localhost:8000;
        proxy_pass_request_headers on;
    
        proxy_http_version 1.1;
    
        proxy_set_header Upgrade $http_upgrade;
    
        proxy_set_header X-ABC-LOGIN-NAME "static_name"; # <-- "static_name" arrives in the python print statement
        proxy_set_header X-ABC-LOGIN-NAME $http_x_abc_login_name;  # <-- This value is empty
    
        proxy_set_header   Connection keep-alive;
        proxy_set_header   Host $host;
        proxy_cache_bypass $http_upgrade;
        proxy_set_header   X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header   X-Forwarded-Proto $scheme;
    
    }

...
}

I exhaustively searched the internet and cannot tell how to find the name of the variable that contains the value, or where it gets lost.


Edit: Adding picture to clarify problem: enter image description here

Inbetween a Browser (Client) and a Server sits a proxy (called ABC). This proxy inserts a Header (X-ABC-LOGIN-NAME) in every request from the client to the server. After inserting the header, the request by the client is forwarded to the Nginx reverse proxy server. From there I am unable to forward the inserted X-ABC-LOGIN-NAME to the gunicorn application server.


Edit 2: nginx -T

ubuntu@xyz-ubuntu:~$ sudo nginx -T
nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
nginx: configuration file /etc/nginx/nginx.conf test is successful
# configuration file /etc/nginx/nginx.conf:
user www-data;
worker_processes auto;
pid /run/nginx.pid;
include /etc/nginx/modules-enabled/*.conf;

events {
        worker_connections 768;
        # multi_accept on;
}

http {

        underscores_in_headers on;

        ##
        # Basic Settings
        ##

        sendfile on;
        tcp_nopush on;
        tcp_nodelay on;
        keepalive_timeout 65;
        types_hash_max_size 2048;
        # server_tokens off;

        server_names_hash_bucket_size 64;
        # server_name_in_redirect off;

        include /etc/nginx/mime.types;
        default_type application/octet-stream;

        ##
        # SSL Settings
        ##

        ssl_protocols TLSv1 TLSv1.1 TLSv1.2 TLSv1.3; # Dropping SSLv3, ref: POODLE
        ssl_prefer_server_ciphers on;

        ##
        # Logging Settings
        ##

        access_log /var/log/nginx/access.log;
        error_log /var/log/nginx/error.log;


        ##
        # Gzip Settings
        ##

        gzip on;

        # gzip_vary on;
        # gzip_proxied any;
        # gzip_comp_level 6;
        # gzip_buffers 16 8k;
        # gzip_http_version 1.1;
        # gzip_types text/plain text/css application/json application/javascript text/xml application/xml application/xml+rss text/javascript;

        ##
        # Virtual Host Configs
        ##

        include /etc/nginx/conf.d/*.conf;
        include /etc/nginx/sites-enabled/*;
}


#mail {
#       # See sample authentication script at:
#       # http://wiki.nginx.org/ImapAuthenticateWithApachePhpScript
#
#       # auth_http localhost/auth.php;
#       # pop3_capabilities "TOP" "USER";
#       # imap_capabilities "IMAP4rev1" "UIDPLUS";
#
#       server {
#               listen     localhost:110;
#               protocol   pop3;
#               proxy      on;
#       }
#
#       server {
#               listen     localhost:143;
#               protocol   imap;
#               proxy      on;
#       }
#}

# configuration file /etc/nginx/modules-enabled/50-mod-http-image-filter.conf:
load_module modules/ngx_http_image_filter_module.so;

# configuration file /etc/nginx/modules-enabled/50-mod-http-xslt-filter.conf:
load_module modules/ngx_http_xslt_filter_module.so;

# configuration file /etc/nginx/modules-enabled/50-mod-mail.conf:
load_module modules/ngx_mail_module.so;

# configuration file /etc/nginx/modules-enabled/50-mod-stream.conf:
load_module modules/ngx_stream_module.so;

# configuration file /etc/nginx/mime.types:

types {
    text/html                             html htm shtml;
    text/css                              css;
    text/xml                              xml;
    image/gif                             gif;
    image/jpeg                            jpeg jpg;
    application/javascript                js;
    application/atom+xml                  atom;
    application/rss+xml                   rss;

    text/mathml                           mml;
    text/plain                            txt;
    text/vnd.sun.j2me.app-descriptor      jad;
    text/vnd.wap.wml                      wml;
    text/x-component                      htc;

    image/png                             png;
    image/tiff                            tif tiff;
    image/vnd.wap.wbmp                    wbmp;
    image/x-icon                          ico;
    image/x-jng                           jng;
    image/x-ms-bmp                        bmp;
    image/svg+xml                         svg svgz;
    image/webp                            webp;

    application/font-woff                 woff;
    application/java-archive              jar war ear;
    application/json                      json;
    application/mac-binhex40              hqx;
    application/msword                    doc;
    application/pdf                       pdf;
    application/postscript                ps eps ai;
    application/rtf                       rtf;
    application/vnd.apple.mpegurl         m3u8;
    application/vnd.ms-excel              xls;
    application/vnd.ms-fontobject         eot;
    application/vnd.ms-powerpoint         ppt;
    application/vnd.wap.wmlc              wmlc;
    application/vnd.google-earth.kml+xml  kml;
    application/vnd.google-earth.kmz      kmz;
    application/x-7z-compressed           7z;
    application/x-cocoa                   cco;
    application/x-java-archive-diff       jardiff;
    application/x-java-jnlp-file          jnlp;
    application/x-makeself                run;
    application/x-perl                    pl pm;
    application/x-pilot                   prc pdb;
    application/x-rar-compressed          rar;
    application/x-redhat-package-manager  rpm;
    application/x-sea                     sea;
    application/x-shockwave-flash         swf;
    application/x-stuffit                 sit;
    application/x-tcl                     tcl tk;
    application/x-x509-ca-cert            der pem crt;
    application/x-xpinstall               xpi;
    application/xhtml+xml                 xhtml;
    application/xspf+xml                  xspf;
    application/zip                       zip;

    application/octet-stream              bin exe dll;
    application/octet-stream              deb;
    application/octet-stream              dmg;
    application/octet-stream              iso img;
    application/octet-stream              msi msp msm;

    application/vnd.openxmlformats-officedocument.wordprocessingml.document    docx;
    application/vnd.openxmlformats-officedocument.spreadsheetml.sheet          xlsx;
    application/vnd.openxmlformats-officedocument.presentationml.presentation  pptx;

    audio/midi                            mid midi kar;
    audio/mpeg                            mp3;
    audio/ogg                             ogg;
    audio/x-m4a                           m4a;
    audio/x-realaudio                     ra;

    video/3gpp                            3gpp 3gp;
    video/mp2t                            ts;
    video/mp4                             mp4;
    video/mpeg                            mpeg mpg;
    video/quicktime                       mov;
    video/webm                            webm;
    video/x-flv                           flv;
    video/x-m4v                           m4v;
    video/x-mng                           mng;
    video/x-ms-asf                        asx asf;
    video/x-ms-wmv                        wmv;
    video/x-msvideo                       avi;
}

# configuration file /etc/nginx/sites-enabled/default:


#
#
# Default server configuration
#
server {
    listen        443 ssl http2 default_server;
    listen [::]:443 ssl http2 default_server;

    ssl_certificate /etc/nginx/ssl/nginx.crt;
    ssl_certificate_key /etc/nginx/ssl/nginx.key;
    ssl_protocols TLSv1 TLSv1.1 TLSv1.2;

    # include snippets/self-signed.conf;
    # include snippets/ssl-params.conf;
    # server_name   localhost;
    server_name xyz_server;

    underscores_in_headers on;

    # REST API Backend
    location ^~ /api  {

        proxy_pass_request_headers on;
    
        proxy_http_version 1.1;
        proxy_set_header   Upgrade $http_upgrade;

        add_header X-Abc-Login-Name $http_x_abc_login_name;

        proxy_set_header   Connection keep-alive;
        proxy_set_header   Host $host;
        proxy_cache_bypass $http_upgrade;
        proxy_set_header   X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header   X-Forwarded-Proto $scheme;

        proxy_pass         http://localhost:8000;
    }

    # Frontend
    location / {

        proxy_pass_request_headers on;

        proxy_http_version 1.1;
        proxy_set_header   Upgrade $http_upgrade;
 
        add_header X-Abc-Login-Name $http_x_abc_login_name;  

        proxy_set_header   Connection keep-alive;
        proxy_set_header   Host $host;
        proxy_cache_bypass $http_upgrade;
        proxy_set_header   X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header   X-Forwarded-Proto $scheme;

        proxy_pass         http://localhost:3000;

    }

    root /var/www/html;
    index index.php;
    location ~ \.php$ {
        include snippets/fastcgi-php.conf;
        fastcgi_pass unix:/run/php/php7.4-fpm.sock;
    }

}

server {

    listen   80; # default_server;

    root /var/www/html;

    index index.php
    server_name php_server;

    location ~ \.php$ {
        include snippets/fastcgi-php.conf;
        fastcgi_pass unix:/run/php/php7.4-fpm.sock;
    }
}

# configuration file /etc/nginx/snippets/fastcgi-php.conf:
# regex to split $uri to $fastcgi_script_name and $fastcgi_path
fastcgi_split_path_info ^(.+?\.php)(/.*)$;

# Check that the PHP script exists before passing it
try_files $fastcgi_script_name =404;

# Bypass the fact that try_files resets $fastcgi_path_info
# see: http://trac.nginx.org/nginx/ticket/321
set $path_info $fastcgi_path_info;
fastcgi_param PATH_INFO $path_info;

fastcgi_index index.php;
include fastcgi.conf;

# configuration file /etc/nginx/fastcgi.conf:

fastcgi_param  SCRIPT_FILENAME    $document_root$fastcgi_script_name;
fastcgi_param  QUERY_STRING       $query_string;
fastcgi_param  REQUEST_METHOD     $request_method;
fastcgi_param  CONTENT_TYPE       $content_type;
fastcgi_param  CONTENT_LENGTH     $content_length;

fastcgi_param  SCRIPT_NAME        $fastcgi_script_name;
fastcgi_param  REQUEST_URI        $request_uri;
fastcgi_param  DOCUMENT_URI       $document_uri;
fastcgi_param  DOCUMENT_ROOT      $document_root;
fastcgi_param  SERVER_PROTOCOL    $server_protocol;
fastcgi_param  REQUEST_SCHEME     $scheme;
fastcgi_param  HTTPS              $https if_not_empty;

fastcgi_param  GATEWAY_INTERFACE  CGI/1.1;
fastcgi_param  SERVER_SOFTWARE    nginx/$nginx_version;

fastcgi_param  REMOTE_ADDR        $remote_addr;
fastcgi_param  REMOTE_PORT        $remote_port;
fastcgi_param  SERVER_ADDR        $server_addr;
fastcgi_param  SERVER_PORT        $server_port;
fastcgi_param  SERVER_NAME        $server_name;

# PHP only, required if PHP was built with --enable-force-cgi-redirect
fastcgi_param  REDIRECT_STATUS    200;

Edit 3:

Left: Application log, Right: Nginx as running:

enter image description here

TMOTTM
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  • Does this answer your question? [Forward Custom Header from Nginx Reverse Proxy](https://serverfault.com/questions/391554/forward-custom-header-from-nginx-reverse-proxy) – djdomi Jul 25 '21 at 12:49
  • I wish.. I found that question and tried to do it as described. However (as I wrote in my question), the value is lost when using `$http_x_abc_login_name` and I am out of ideas why that might be (given that the phpinfo() running behind the same reverse proxy receives the value). – TMOTTM Jul 25 '21 at 13:22
  • did you see `underscores_in_headers on;` and applied it? – djdomi Jul 25 '21 at 15:25
  • Absolutely. It is set in the `server { underscores_in_headers on; ...}` section. Added that section to the nginx defaults file in my original question post. – TMOTTM Jul 25 '21 at 17:07
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    What you have posted should have worked fine from the beginning. It's time to look a bit farther out. Please post the output of `nginx -T` – Michael Hampton Jul 25 '21 at 17:19
  • @MichaelHampton I added the output. It is the state of the configuration after the latest suggestion by djdomi (using `add_header`). – TMOTTM Jul 25 '21 at 19:49
  • Well that won't work. `add_header` adds a response header. Change it back to `proxy_set_header` in both locations. – Michael Hampton Jul 25 '21 at 19:50
  • I reverted back to `proxy_set_header`. As shown to the left, the application can receive and print the statit "TEST" header. Not so however with the `http_x_hin_login_name`. But I know that it is there because phpinfo() sees it in PHP Variables. – TMOTTM Jul 25 '21 at 21:24
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    Hmm, so why do you try to pass this header explicitly? They all should be sent to your app anyway if you do nothing, just like all the others are. – Michael Hampton Jul 25 '21 at 22:14
  • I can write an `if` Statement that returns a 412 like this `if ($http_x_hin_login_name) { return 412; }` and I get the 412 status code. But I dont receive this header in my app. – TMOTTM Jul 26 '21 at 14:52

0 Answers0