# The INVENTAIRE_PORT and PUBLIC_HOSTNAME variables are set with nginx image function,
# which will extract environment variables before nginx starts
# See https://hub.docker.com/_/nginx

upstream inventaire {
    server inventaire:${INVENTAIRE_PORT} fail_timeout=5s;
}

# Using error_page as a way to have a named location that can
# then be shared between several locations, see:
# https://serverfault.com/questions/908086/nginx-directly-send-from-location-to-another-named-location
# https://www.nginx.com/resources/wiki/start/topics/depth/ifisevil/#what-to-do-instead
# Contrary to what the documentation says, the HTTP verbs aren't all converted to GET
# http://nginx.org/en/docs/http/ngx_http_core_module.html#error_page
error_page 543 = @invserver;

server {
    listen 80;
    listen [::]:80;

    # Required to be able to run `certbot -w /var/www/html/`
    location /.well-known/ {
        root /var/www/html/;
    }

    location / {
        return 301 https://$host$request_uri;
    }
}

server {
    listen 443 ssl http2;
    listen [::]:443 ssl http2;
    server_name ${PUBLIC_HOSTNAME};

    ssl_certificate /etc/letsencrypt/live/${PUBLIC_HOSTNAME}/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/${PUBLIC_HOSTNAME}/privkey.pem;

    include /etc/nginx/snippets/ssl.conf;

    client_max_body_size 25M;

    # Disabling compression to mitigate BREACH exploit
    # https://en.wikipedia.org/wiki/BREACH_(security_exploit)#Mitigation
    # http://security.stackexchange.com/questions/39925/breach-a-new-attack-against-http-what-can-be-done
    # until we can confidently say that HTTP/2 solves the issue? https://blog.cloudflare.com/hpack-the-silent-killer-feature-of-http-2
    gzip off;

    # On-The-Fly Image Resizer

    # URLs look like /img/users/300x1200/8185d4e039f52b4faa06a1c277133e9a8232551b
    # for locally hosted images
    # or /img/remote/300x1200/630022006?href=http%3A%2F%2Fescaped.url
    # for remote images, with 630022006 being the hash of the passed href
    # generated by [hashCode](https://git.inventaire.io/inventaire/blob/35b1e63/server/lib/utils/base.js#L69-L80)

    # The hack: I couldn't make the proxy_store work: it never hits the cache, but
    # it does put the resized images in /tmp/nginx/resize, so using a try_files
    # directive instead

    # Sometimes, for some unidentified reason, the cached files end up empty, so it can be useful to add a root cron to remove those files:
    # 0 4 * * * /usr/bin/find /tmp/nginx -type f -size 0 -delete

    # Do not remove the (.*) capture group as it seems to be required by the try_files
    location ~ ^/img/(groups|users|entities|assets)/(.*) {
       include /etc/nginx/snippets/security_headers.conf;
       root /tmp/nginx/resize;
       default_type "image/jpeg";
       add_header Cache-Control "public, max-age=31536000, immutable";
       add_header X-File-Cache "hit";
       add_header Content-Security-Policy "sandbox";
       try_files $uri @invimg;
       limit_except GET {
           deny  all;
       }
    }

    # Same as above, but without the immutable
    location ~ ^/img/remote/(.*) {
       include /etc/nginx/snippets/security_headers.conf;
       root /tmp/nginx/resize;
       default_type "image/jpeg";
       add_header X-File-Cache "hit";
       add_header Content-Security-Policy "sandbox";
       try_files $uri @invimg;
       limit_except GET {
           deny  all;
       }
    }

    # following aliases made in order to respect the url structure
    # the server alone would follow: especially, mounting /static on /public
    root  /opt/inventaire/client;
    location /public/ {
        include /etc/nginx/snippets/security_headers.conf;
        limit_except GET {
            deny  all;
        }
        gzip_static on;
        # Let resources that can't be cache busted
        # - such as opensearch.xml or robots.txt -
        # out of this caching policy
        if ($uri ~ "^/public/(dist|fonts)/" ) {
            include /etc/nginx/snippets/security_headers.conf;
            add_header Cache-Control "public, max-age=31536000, immutable";
            # All headers that aren't in the last block won't be taken in account
            # thus the need to have CORS headers here too
            add_header 'Access-Control-Allow-Origin' '*' always;
            add_header 'Access-Control-Allow-Methods' 'GET' always;
        }
    }

    # Pass the request to the node.js server
    # with some correct headers for proxy-awareness
    location /api {
        return 543;
    }

    location /.well-known/webfinger {
        return 543;
    }

    # Let the API server handle all but /public JSON and RSS requests
    location ~ "^/[^p].*\.(json|rss)$" {
        limit_except GET {
            deny  all;
        }
        return 543;
    }

    location @invserver {
        include /etc/nginx/snippets/security_headers.conf;
        # Let the server decide when CORS headers should be added
        proxy_set_header Host $http_host;
        proxy_set_header X-Forwarded-Proto https;
        proxy_set_header Host $host;

        # Set a large value to let the API determine the appropriate
        # timeout per endpoint
        # http://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_read_timeout
        proxy_read_timeout 3600;
        proxy_redirect off;
        proxy_http_version 1.1;
        proxy_pass http://inventaire;
    }

    location = /favicon.ico {
        include /etc/nginx/snippets/security_headers.conf;
        try_files /public/$uri /public/images/$uri;
        expires 30d;
        add_header Cache-Control "public";
    }

    location = /robots.txt {
        include /etc/nginx/snippets/security_headers.conf;
        gzip_static on;
        try_files /public/$uri /$uri;
        expires 1d;
        add_header Cache-Control "public";
    }

    # Prevent exposing git folders such as /public/i18n/.git
    # For why this rule takes precedence over location /public/
    # see http://stackoverflow.com/a/34262192/3324977
    location ~ /\.git {
        deny all;
    }

    location ^~ '/.well-known/acme-challenge' {
      include /etc/nginx/snippets/security_headers.conf;
      default_type "text/plain";
      root /var/www/certbot;
    }
}