Summary

A simple static HTTP 1.1 + TLS 1.2 server that loads some files into RAM before serving

Disclaimer

This is a toy project, I have no idea what I'm doing. Do not use in production

Purpose

This server uses Linux io_uring + BearSSL. It is reasonably fast and has predictable memory usage. While the server is running, it is not allocating memory dynamically

Building

0. Take a look at src/config.zig for any parameters to adjust
1. Get BearSSL from https://bearssl.org/
2. Compile the BearSSL static lib. Put it into lib/ folder
3. BearSSL includes go into include/bearssl/ folder
4. This currently compiles with Zig 0.13. I would recommend using zig build --release=safe due to the fact that it preserves boundary checks
5. Compiled binary is located at zig-out/bin folder

Running

1. Due to io_uring, this server requires Linux with a recent kernel. I have tested it on Ubuntu Server 24.04 LTS
2. You would need to adjust nofile limits to exceed the number of concurrent connections in the config
3. This server is recommended to run as a regular user (not root). This means the html folder and key files must be readable by that user.
4. To run the binary, you need to provide 4 arguments: hostname, html folder to serve, certificate pem file, certificate key file. E.g. /usr/local/bin/zzini-server localhost public/ /my/cert.pem /my/key.pem
5. For testing purposes, you can generate self-signed keys using OpenSSL

Misc

• The server doesn't monitor files. Any changes require a server restart
• This isn't server really HTTP/1.1 compliant because it serves only gzipped files (among other issues). This should work with modern browsers though.
• I have added an example systemd service config as an illustration
• For now, the server supports only ED25519 and RSA keys
• This server should work with Certbot Lets Encrypt SSL keys, but because of the non-root user it requires fiddling with chown and post-hooks
• It is possible to compile this with Tracy debugger support, but it's not necessary.
• The main reason for this project for me was to learn Zig and io_uring

Benchmarks

Here are some lazy benchmarks on my machine on a single thread against localhost (on 9090 and 9091 ports + allow insecure http, changeable in the config)

Built with zig build --release=fast

• HTTP

oha -z10s -c 1024 http://localhost:9090

Summary:
  Success rate: 100.00%
  Total:        10.0064 secs
  Slowest:      0.8829 secs
  Fastest:      0.0000 secs
  Average:      0.0061 secs
  Requests/sec: 166763.8429

  Total data:   206.81 MiB
  Size/request: 130 B
  Size/sec:     20.67 MiB

Response time histogram:
  0.000 [1]       |
  0.088 [1667679] |■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■
  0.177 [197]     |
  0.265 [36]      |
  0.353 [38]      |
  0.441 [35]      |
  0.530 [34]      |
  0.618 [33]      |
  0.706 [34]      |
  0.795 [34]      |
  0.883 [30]      |

• HTTPS with reuse (2048 RSA key)

oha -z10s --insecure -c 1024 https://localhost:9091

Summary:
  Success rate: 100.00%
  Total:        10.0070 secs
  Slowest:      2.4513 secs
  Fastest:      0.0001 secs
  Average:      0.0095 secs
  Requests/sec: 105917.8430

  Total data:   131.32 MiB
  Size/request: 130 B
  Size/sec:     13.12 MiB

Response time histogram:
  0.000 [1]       |
  0.245 [1058184] |■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■
  0.490 [0]       |
  0.735 [0]       |
  0.981 [0]       |
  1.226 [0]       |
  1.471 [512]     |
  1.716 [332]     |
  1.961 [63]      |
  2.206 [61]      |
  2.451 [55]      |

• HTTPS without reuse (2048 RSA key)

oha -z10s --insecure -c 1024 https://localhost:9091 --disable-keepalive

Summary:
  Success rate: 100.00%
  Total:        10.0221 secs
  Slowest:      2.1511 secs
  Fastest:      0.1397 secs
  Average:      1.6962 secs
  Requests/sec: 642.3809

  Total data:   688.09 KiB
  Size/request: 130 B
  Size/sec:     68.66 KiB

Response time histogram:
  0.140 [1]    |
  0.341 [131]  |■
  0.542 [116]  |
  0.743 [114]  |
  0.944 [114]  |
  1.145 [115]  |
  1.347 [114]  |
  1.548 [117]  |
  1.749 [132]  |■
  1.950 [4133] |■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■
  2.151 [333]  |■■