Mattermost module does not create postgres database anymore

[arianvp]

Issue description

Something changed in the postgres module such that the mattermost module is now broken.
If you deploy mattermost for the first time, it should set up a postgres database through the ExecStartPre script. However, this script fails because psql cannot connect to the postgres UNIX Domain Socket. It seems postgres now listens on tcp instead of unix domain socket. So the script is not correct anymore

The Fix:

Force psql to connect to 127.0.0.1. It will then fallback to TCP connection. this is a hack though it seems...

Steps to reproduce

  services.mattermost = {
    enable = true;
  };

now run nixos-rebuild switch

Technical details

• System:

[nixos@arianvp:/]$ nixos-version
16.09.1536.dc6a857 (Flounder)

• Nix version: (run nix-env --version)

[nixos@arianvp:/]$ nix-env --version
nix-env (Nix) 1.11.6

• Nixpkgs version: (run nix-instantiate --eval '<nixpkgs>' -A lib.nixpkgsVersion)

[nixos@arianvp:/]$ nix-instantiate --eval '<nixpkgs>' -A lib.nixpkgsVersion
"16.09.1229.f52eaf4"

[arianvp]

I fixed this by changing PrivateTmp=true to PrivateTmp=false

I'll open a pull request