nginx NixOS module: generated configuration has many superfluous newlines

[coretemp]

Issue description

A generated nginx configuration file contains many newlines, which make the file much longer than needed (and it makes it harder to read).

Steps to reproduce

service.nginx.enable = true;

Technical details

• system: "x86_64-linux"
• host os: Linux 4.13.4, NixOS, 17.09.git.39cd40f (Hummingbird)
• multi-user?: yes
• sandbox: no
• version: nix-env (Nix) 1.11.15
• channels(root): "nixos-17.09.2182.7f6f0c49f0"
• nixpkgs: /nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs

[Baughn]

I had a nginx configuration file cleaner submitted a while back, but it got backed out for not working quite right. (Around Unicode, iirc.)

Perhaps it's time to take another look at that.

[rnhmjoj]

Nginx is particularly bad because the expression is quite complicated but this applies to practically every configuration files NixOS generates. Here's some

xorg.conf

Section "Device"
  Identifier "Device-amdgpu[0]"
  Driver "amdgpu"
  Option "AccelMethod" "glamor"
  Option "DRI"      "3"
Option "TearFree" "true"

  
EndSection

Section "Screen"
  Identifier "Screen-amdgpu[0]"
  Device "Device-amdgpu[0]"
  

  

  

  

EndSection

torrc.conf

GeoIPv6File /nix/store/d12qh0yn9q3qa7xnbsi0bwva1dcvmmmm-tor-0.3.2.9-geoip/share/tor/geoip6



SOCKSPort 127.0.0.1:9050 IsolateDestAddr
SOCKSPort 127.0.0.1:9063





# Performance
AvoidDiskWrites      1
HardwareAccel        1

homeserver.yaml

 no_tls: false




 pid_file: "/var/run/matrix-synapse.pid"
 web_client: true

 listeners: [{port: 8448, bind_address: "", type: http,

Personally I don't care much about the generated files: I'm not going to read it after I tested the module but It would be a nice improvement. If you try to generate clean files the code usually turns into a mess. A possible solution could be to remove empty lines. Not sure about the broken indentation.

[lheckemann]

Workaround: view the file through sed 's/^\s*$//' | uniq

[bobvanderlinden]

Allternatively we could use https://github.com/vasilevich/nginxbeautifier if needing minimal nodejs at build-time isn't a problem.

EDIT: Also found https://github.com/1connect/nginx-config-formatter, which is written in python.

[infinisil]

For my #45470 I implemented a config variable having some Nix type (some combination of attrsets and lists), which then gets turned into the config string. Due to it being generated like this, the formatting of the config file has improved a lot: old new

The same could be done for postgresql.

[globin]

Is formatted now.