How to allow CORS on NGINX - nginx

Question

So I want my domain scanner-api.local to accept file sent from mobile device/web apps .
I was getting
following error
MLHttpRequest cannot load http://scanner-api.local/upload. No
'Access-Control-Allow-Origin' header is present on the requested
resource. Origin 'http://localhost:3000' is therefore not allowed
access.
I tried to add following in my Nginx server but its not working , Nginx is crashing
code
server {
listen 80;
listen [::]:80;
# 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/stock_scan_api/public/;
# Add index.php to the list if you are using PHP
index index.php index.html index.htm index.nginx-debian.html;
server_name scanner-api.local;
#location / {
# # First attempt to serve request as file, then
# # as directory, then fall back to displaying a 404.
# try_files $uri $uri/ =404;
#}
location / {
# First attempt to serve request as file, then
# as directory, then fall back to displaying a 404.
try_files $uri $uri/ /index.php?$query_string;
# Uncomment to enable naxsi on this location
# include /etc/nginx/naxsi.rules
}
# pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000
#
location ~ \.php$ {
include snippets/fastcgi-php.conf;
# With php7.0-cgi alone:
# fastcgi_pass 127.0.0.1:9000;
# # With php7.0-fpm:
fastcgi_pass unix:/run/php/php7.0-fpm.sock;
}
# deny access to .htaccess files, if Apache's document root
# concurs with nginx's one
#
#location ~ /\.ht {
# deny all;
#}
location / {
if ($request_method = 'OPTIONS') {
add_header 'Access-Control-Allow-Origin' '*';
add_header 'Access-Control-Allow-Credentials' 'true';
add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS';
add_header 'Access-Control-Allow-Headers' 'DNT,X-CustomHeader,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type';
add_header 'Access-Control-Max-Age' 1728000;
add_header 'Content-Type' 'text/plain charset=UTF-8';
add_header 'Content-Length' 0;
return 204;
}
if ($request_method = 'POST') {
add_header 'Access-Control-Allow-Origin' '*';
add_header 'Access-Control-Allow-Credentials' 'true';
add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS';
add_header 'Access-Control-Allow-Headers' 'DNT,X-CustomHeader,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type';
}
if ($request_method = 'GET') {
add_header 'Access-Control-Allow-Origin' '*';
add_header 'Access-Control-Allow-Credentials' 'true';
add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS';
add_header 'Access-Control-Allow-Headers' 'DNT,X-CustomHeader,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type';
}
}
}
What could be the error in this ?

Answer 1

Try removing the single quotes surrounding the header and value like:
add_header Access-Control-Allow-Origin *;