{ lib, pkgs, config, myconfig, mylibs, ... }:
let
    cfg = config.services.myDatabases;
in {
  options.services.myDatabases = {
    postgresql = {
      enable = lib.mkOption {
        default = cfg.enable;
        example = true;
        description = "Whether to enable postgresql database";
        type = lib.types.bool;
      };
    };
  };

  config = lib.mkIf cfg.enable {
    nixpkgs.overlays = [ (self: super: rec {
      postgresql = postgresql_11;
      postgresql_11 = super.postgresql_11.overrideAttrs(old: rec {
        passthru = old.passthru // { psqlSchema = "11.0"; };
        configureFlags = old.configureFlags ++ [ "--with-pam" ];
        buildInputs = (old.buildInputs or []) ++ [ self.pam ];
        patches = old.patches ++ [
          ./postgresql_run_socket_path.patch
        ];
      });
    }) ];

    networking.firewall.allowedTCPPorts = [ 5432 ];

    security.acme.certs."postgresql" = config.services.myCertificates.certConfig // {
      user = "postgres";
      group = "postgres";
      plugins = [ "fullchain.pem" "key.pem" "account_key.json" ];
      domain = "db-1.immae.eu";
      postRun = ''
        systemctl reload postgresql.service
      '';
    };

    system.activationScripts.postgresql = ''
      install -m 0755 -o postgres -g postgres -d ${myconfig.env.databases.postgresql.socket}
      '';

    systemd.services.postgresql.serviceConfig.SupplementaryGroups = "keys";
    services.postgresql = rec {
      enable = cfg.postgresql.enable;
      package = pkgs.postgresql;
      enableTCPIP = true;
      extraConfig = ''
        max_connections = 100
        wal_level = logical
        shared_buffers = 512MB
        work_mem = 10MB
        max_wal_size = 1GB
        min_wal_size = 80MB
        log_timezone = 'Europe/Paris'
        datestyle = 'iso, mdy'
        timezone = 'Europe/Paris'
        lc_messages = 'en_US.UTF-8'
        lc_monetary = 'en_US.UTF-8'
        lc_numeric = 'en_US.UTF-8'
        lc_time = 'en_US.UTF-8'
        default_text_search_config = 'pg_catalog.english'
        ssl = on
        ssl_cert_file = '/var/lib/acme/postgresql/fullchain.pem'
        ssl_key_file = '/var/lib/acme/postgresql/key.pem'
        '';
      authentication = ''
        local	all	postgres				ident
        local	all	all					md5
        hostssl	all	all	188.165.209.148/32		md5
        hostssl	all	all	178.33.252.96/32		md5
        hostssl	all	all	all				pam
        hostssl	replication	backup-1	2001:41d0:302:1100::9:e5a9/128	pam pamservice=postgresql_replication
        hostssl	replication	backup-1	54.37.151.137/32		pam pamservice=postgresql_replication
      '';
    };

    mySecrets.keys = [
      {
        dest = "postgresql/pam";
        permissions = "0400";
        group = "postgres";
        user = "postgres";
        text =  with myconfig.env.databases.postgresql.pam; ''
          host ${myconfig.env.ldap.host}
          base ${myconfig.env.ldap.base}
          binddn ${dn}
          bindpw ${password}
          pam_filter ${filter}
          ssl start_tls
        '';
      }
      {
        dest = "postgresql/pam_replication";
        permissions = "0400";
        group = "postgres";
        user = "postgres";
        text = ''
          host ${myconfig.env.ldap.host}
          base ${myconfig.env.ldap.base}
          binddn ${myconfig.env.ldap.host_dn}
          bindpw ${myconfig.env.ldap.password}
          pam_login_attribute cn
          ssl start_tls
        '';
      }
    ];

    security.pam.services = let
      pam_ldap = "${pkgs.pam_ldap}/lib/security/pam_ldap.so";
    in [
      {
        name = "postgresql";
        text = ''
          auth    required ${pam_ldap} config=/var/secrets/postgresql/pam
          account required ${pam_ldap} config=/var/secrets/postgresql/pam
          '';
      }
      {
        name = "postgresql_replication";
        text = ''
          auth    required ${pam_ldap} config=/var/secrets/postgresql/pam_replication
          account required ${pam_ldap} config=/var/secrets/postgresql/pam_replication
          '';
      }
    ];
  };
}