How to view all mongodb queries?

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1

Where can I find /var/log/mongodb/mongod.log?

I have this in configuration.nix:

{
  #...
  services.mongodb = {
    package = pkgs.mongodb-4_2;
    #bind_ip = "0.0.0.0";
    enable = true;
    extraConfig = ''
      operationProfiling.mode: all
    '';
  };
}

As I understand to log all queries I should set mongod --profile=2 when running from terminal or operationProfiling.mode: all using mongod.conf

EDIT: I see that in nixpkgs/mongodb.nix at 573095944e7c1d58d30fc679c81af63668b54056 · NixOS/nixpkgs · GitHub

systemLog.destination: syslog

so logs should accessible with journalctl? But I don’t see anything here:

$ sudo journalctl -f -u mongod
-- Journal begins at Tue 2021-11-09 20:09:36 CET. --

EDIT2: I have added systemLog.quiet: false but still no logs with journalctl:

{
  #...
  services.mongodb = {
    package = pkgs.mongodb-4_2;
    #bind_ip = "0.0.0.0";
    enable = true;
    extraConfig = ''
      operationProfiling.mode: all
      systemLog.quiet: false
    '';
  };
}

EDIT3:

$ mongo
> db.getProfilingStatus()
{ "was" : 2, "slowms" : 100, "sampleRate" : 1 }

EDIT4:

And this is when I don’t set operationProfiling.mode:

> db.getProfilingStatus()
{ "was" : 0, "slowms" : 100, "sampleRate" : 1
2

Profilings are attached to collection in mongodb:

db.system.profile.find({"ns": "portal.users"}).sort({ts:-1}).limit(1).pretty():

or db.system.profile.find({"ns": "portal.users", "command.find": "users" }).sort({ts:-1}).limit(1).pretty()