2022-06-04_-_bash_and_raii_-_continued

anonymous@undisclosed.example.com (Anonymous) — Sat, 04 Jun 2022 20:20:51 +0000

2022-06-04 - bash and RAII - continued

couple days ago i wrote about RAII in bash. i forgot to mention 1 more thing there. when cleanup procedure is more complicated than simple rm -rf foobar it's worth to make it a separate function:

# ...
function cleanup
{
  rm -rf "$VAR_TO_SANITIZE"
  rm -fv /path/to/lock
  umount /media/foobar
}
trap cleanup EXIT
# ...

2022-06-04_-_caching_proxy_in_nginx

anonymous@undisclosed.example.com (Anonymous) — Sat, 04 Jun 2022 20:29:46 +0000

2022-06-04 - caching proxy in nginx

in one of the previous projects we had an issue on CI. TL;DR – we needed a cache, to minimize network traffic between different locations. case was simple: there were build artifacts, stored on site A and these were needed N times on site B. since the files (once published) never changed, it was a simple matter of keeping a copy on site B, when it was 1st downloaded from site A.

after some digging it turned out that nginx has a ready-to-go solution for exactly that! this is how an example configuration (nginx.conf) looks like:

user www-data;
worker_processes auto;
pid /run/nginx.pid;
include /etc/nginx/modules-enabled/*.conf;

events {
    worker_connections 1024;
    # multi_accept on;
}


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

    client_max_body_size 2048M;
    gzip off;

    server {
        listen 80 default_server;
        listen [::]:80 default_server;
        proxy_cookie_path / "/; HttpOnly; Secure";
        server_name _;
        return 301 https://$host$request_uri;
    }

    proxy_cache_path  /var/cache/nginx/ levels=1:2 keys_zone=STATIC:10m inactive=15d max_size=1800g;
    server {
        listen 443 ssl default_server;
        listen [::]:443 ssl default_server;
        proxy_cookie_path / "/; HttpOnly; Secure";
        server_name _;

        ssl_protocols TLSv1.2 TLSv1.3;
        ssl_certificate     /path/to/cert.pem;
        ssl_certificate_key /path/to/key.pem;

        location / {
            proxy_pass             https://actual.server.to.offload;
            proxy_cache_methods    GET HEAD;
            proxy_set_header       Host $host;
            proxy_buffering        on;
            proxy_cache            STATIC;
            proxy_cache_valid      200  10d;
            proxy_cache_use_stale  error timeout invalid_header updating
                                   http_500 http_502 http_503 http_504;
        }
    }
}

this coveres: caching, cache lifetime management, HTTPS and HTTP to HTTPS redirection. all in 49 lines of config, including formatting. :D once deployed, there were no further issues observed. XXI century magic! ;)

2022-06-04_-_protecting_private_e-mail

anonymous@undisclosed.example.com (Anonymous) — Sat, 04 Jun 2022 20:32:38 +0000

2022-06-04 - protecting private e-mail