How to serve multiple node apps in a single digitalocean vps server? - node.js

Question

Below given is my /etc/nginx/sites-available/default file. I have added the two new location blocks with their respective localhost links, only the root one, with localhost 8000 is being server by nginx. The other two links doesn't work.
Example
http://111.111.111.111 = Works
http://111.111.111.111/app1 = Doesn't work
http://111.111.111.111/app2 = Doesn't work
http://111.111.111.111:3000 = Doesnt't work
http://111.111.111.111:4000 = Doesnt't work
How do I fix the following file so that I can access the three node apps running on three ports(3000, 4000 and 8000). Thanks in advance for any help
server {
listen 80 default_server;
listen [::]:80 default_server;
# SSL configuration
#
# listen 443 ssl default_server;
# listen [::]:443 ssl default_server;
#
# Note: You should disable gzip for SSL traffic.
# See: https://bugs.debian.org/773332
#
# Read up on ssl_ciphers to ensure a secure configuration.
# See: https://bugs.debian.org/765782
#
# Self signed certs generated by the ssl-cert package
# Don't use them in a production server!
#
# include snippets/snakeoil.conf;
# root /var/www/html;
# Add index.php to the list if you are using PHP
index index.html index.htm index.nginx-debian.html;
server_name _;
location /app1 {
proxy_pass http://localhost:4000;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection "upgrade";
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_set_header X-Forwarded-Proto $scheme;
}
location /app2 {
proxy_pass http://localhost:3000;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection 'upgrade';
proxy_set_header Host $host;
proxy_cache_bypass $http_upgrade;
}
location / {
proxy_pass http://localhost:8000;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection 'upgrade';
proxy_set_header Host $host;
proxy_cache_bypass $http_upgrade;
}
# pass PHP scripts to FastCGI server
#
#location ~ \.php$ {
# include snippets/fastcgi-php.conf;
#
# # With php-fpm (or other unix sockets):
# fastcgi_pass unix:/var/run/php/php7.0-fpm.sock;
# # With php-cgi (or other tcp sockets):
# fastcgi_pass 127.0.0.1:9000;
#}
# deny access to .htaccess files, if Apache's document root
# concurs with nginx's one
#
#location ~ /\.ht {
# deny all;
#}
}
Below is mt etc/nginx/nginx.conf file
user www-data;
worker_processes auto;
pid /run/nginx.pid;
include /etc/nginx/modules-enabled/*.conf;
events {
worker_connections 768;
# multi_accept on;
}
http {
##
# 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; # 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;
# }
#}

Answer 1

For a full configuration, check out my answer to Configuring Load Balancer to Route to different pages of instance?. You don't need the root /var/www/html; as you aren't serving a static html page.
You need the proper forwarding headers:
location /app1 {
proxy_pass http://localhost:4000;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection "upgrade";
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_set_header X-Forwarded-Proto $scheme;
}
You should also use 127.0.0.1 over localhost, and create a block for each upstream node.js server nginx is acting as a reverse-proxy for:
upstream root {
server 127.0.0.1:8000;
keepalive 256;
}
upstream app1 {
server 127.0.0.1:4000
keepalive 256;
}
upstream app2 {
server 127.0.0.1:3000
keepalive 256;
}
server {
listen 80 default_server;
location / {
proxy_pass http://root;
proxy_pass_header Access-Control-Allow-Origin;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header Host $http_host;
proxy_set_header X-NginX-Proxy true;
proxy_pass_header Set-Cookie;
proxy_pass_header X-UA-Compatible;
proxy_pass_header Server;
proxy_buffers 64 16k;
proxy_buffer_size 16k;
proxy_busy_buffers_size 64k;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection $http_connection;
proxy_read_timeout 10;
proxy_redirect off;
}
location /app1 {
proxy_pass http://app1;
proxy_pass_header Access-Control-Allow-Origin;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header Host $http_host;
proxy_set_header X-NginX-Proxy true;
proxy_pass_header Set-Cookie;
proxy_pass_header X-UA-Compatible;
proxy_pass_header Server;
proxy_buffers 64 16k;
proxy_buffer_size 16k;
proxy_busy_buffers_size 64k;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection $http_connection;
proxy_read_timeout 10;
proxy_redirect off;
}
location /app2 {
proxy_pass http://app2;
proxy_pass_header Access-Control-Allow-Origin;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header Host $http_host;
proxy_set_header X-NginX-Proxy true;
proxy_pass_header Set-Cookie;
proxy_pass_header X-UA-Compatible;
proxy_pass_header Server;
proxy_buffers 64 16k;
proxy_buffer_size 16k;
proxy_busy_buffers_size 64k;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection $http_connection;
proxy_read_timeout 10;
proxy_redirect off;
}
}