Here is my current systemd service:

systemd.services.myservice = {
    wantedBy = ["multi-user.target"];
    after = ["network-online.target"];
    serviceConfig = {
      Type = "simple";
      ExecStart = "PORT=5173 ${pkgs.nodejs_20}/bin/node .";
      WorkingDirectory = inputs.myservice.packages.${pkgs.system}.default;
      Restart = "always";
    };
  };

In reply to @lily:lily.flowers
PORT=5173 is not a command

it is just a command line

from the docs:

PORT, HOST and SOCKET_PATHpermalink
By default, the server will accept connections on 0.0.0.0 using port 3000. These can be customised with the PORT and HOST environment variables:

HOST=127.0.0.1 PORT=4000 node build
Alternatively, the server can be configured to accept connections on a specified socket path. When this is done using the SOCKET_PATH environment variable, the HOST and PORT environment variables will be disregarded.

SOCKET_PATH=/tmp/socket node build

In reply to @lily:lily.flowers
PORT=5173 is not a command

it is just a command line argument

from the docs:

PORT, HOST and SOCKET_PATHpermalink
By default, the server will accept connections on 0.0.0.0 using port 3000. These can be customised with the PORT and HOST environment variables:

HOST=127.0.0.1 PORT=4000 node build
Alternatively, the server can be configured to accept connections on a specified socket path. When this is done using the SOCKET_PATH environment variable, the HOST and PORT environment variables will be disregarded.

SOCKET_PATH=/tmp/socket node build

The unit myapp.service has entered the 'failed' state with result 'exit-code'.
Nov 12 14:21:52 server systemd[1]: Failed to start My application
░░ Subject: A start job for unit myapp.service has failed
░░ Defined-By: systemd
░░ Support: https://lists.freedesktop.org/mailman/listinfo/systemd-devel
░░ 
░░ A start job for unit myapp.service has finished with a failure.
░░ 
░░ The job identifier is 1062533 and the job result is failed.

In reply to @peter-lustig:matrix.org

Here is my current systemd service:

systemd.services.myservice = {
    wantedBy = ["multi-user.target"];
    after = ["network-online.target"];
    serviceConfig = {
      Type = "simple";
      ExecStart = "PORT=5173 ${pkgs.nodejs_20}/bin/node .";
      WorkingDirectory = inputs.myservice.packages.${pkgs.system}.default;
      Restart = "always";
    };
  };

In reply to @lily:lily.flowers
can you ping me in like 5 hours? i'm running an event at the moment, but can help later

In reply to @szucsitg:matrix.org
Maybe now?

In reply to @peter-lustig:matrix.org

The unit myapp.service has entered the 'failed' state with result 'exit-code'.
Nov 12 14:21:52 server systemd[1]: Failed to start My application
░░ Subject: A start job for unit myapp.service has failed
░░ Defined-By: systemd
░░ Support: https://lists.freedesktop.org/mailman/listinfo/systemd-devel
░░ 
░░ A start job for unit myapp.service has finished with a failure.
░░ 
░░ The job identifier is 1062533 and the job result is failed.

systemd.services.myapp = {
    description = "My application";
    wantedBy = ["multi-user.target"];
    wants = ["network-online.target"];
    serviceConfig = {
      Type = "simple";
      Environment = "PORT=5173";
      ExecStart = "${pkgs.nodejs_20}/bin/node .";
      WorkingDirectory = inputs.myapp.packages.${pkgs.system}.default;
      Restart = "always";
    };
  };