I just switched one of my systems over to NixOS from Arch and so far it seems interesting. One question I had is regarding the nix-shell. So I get the basic concept of it and that it allows creating a shell that has packages installed with that shell making ideal for dev environments. I’ve even seen talks where the suggest nix-shells over docker/podman, my question is how is persistent data (like databases) handled?

  • vendion@lemmy.mlOP
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    8 months ago

    Okay, hopefully someone here can point out where I am going wrong with setting up my dev shell the way I want. I am currently using direnv and nix-direnv to manage the dev shell, and I found this blog post which shows a way to start and stop MySQL/Mariadb but I am having some weird issues with it.

    Currently my flake looks like this:

    {
      description = "A basic flake with a shell";
      inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
      inputs.flake-utils.url = "github:numtide/flake-utils";
    
      outputs = { nixpkgs, flake-utils, ... }@inputs:
        flake-utils.lib.eachDefaultSystem (system:
          let
            pkgs = nixpkgs.legacyPackages.${system};
          in
          {
            devShells.default = pkgs.mkShell {
              packages = with pkgs; [
                bashInteractive
                php
              ];
    
              buildInputs = [ pkgs.mariadb ];
    
              shellHook = ''
              export MYSQL_BASEDIR=${pkgs.mariadb}
              export MYSQL_HOME=$PWD/.direnv/mysql
              export MYSQL_DATADIR=$MYSQL_HOME/data
              export MYSQL_UNIX_PORT=$MYSQL_HOME/mysql.sock
              export MYSQL_PID_FILE=$MYSQL_HOME/mysql.pid
              alias mysql='mysql -u root'
    
              if [[ ! -d $MYSQL_HOME ]]; then
                mariadb-install-db --auth-root-authentication-method=normal \
                  --datadir="$MYSQL_DATADIR" --basedir="$MYSQL_BASEDIR" \
                  --pid-file="$MYSQL_PID_FILE"
              fi
    
              mariadbd --datadir=$MYSQL_DATADIR --pid-file=$MYSQL_PID_FILE \
                --socket=$MYSQL_UNIX_PORT --tmpdir='/tmp' 2>/dev/null &
              MYSQL_PID=$!
              '';
            };
          });
    }
    

    When I run it like this mariadbd starts just fine, but doesn’t get backgrounded dispite the & making that shell session useless which is not what I want as I have to spawn a second shell just to do anything.

    Even weirder is when I add the finish() function and the call to trap like in the blog post then mariadbd doesn’t start (or starts and immedently gets killed).

    • onlinepersona@programming.dev
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      4 months ago

      mariadb doesn’t get backgrounded? Are you sure? Are you able to type commands and see their output? Also, what happens when putting set -x at the start of your shell hook? You should see the last line printed e.g MYSQL_PID=12345

      Anti Commercial-AI license