add zammad to fw vm, add web-arm machine

hosts/web-arm/modules/mysql.nix

@@ -0,0 +1,78 @@
+{ pkgs, ... }:
+
+let
+  mysqlCreateDatabase = pkgs.writeShellScriptBin "mysql-create-database" ''
+    #!/usr/bin/env bash
+    if [ $# -lt 2 ]
+    then
+      echo "Usage: $0 <database> <host>"
+      exit 1
+    fi
+
+    if ! [ $EUID -eq 0 ]
+    then
+      echo "Must be root!" >&2
+      exit 1
+    fi
+
+    DB="$1"
+    HOST="$2"
+    PASSWORD="$(tr -dc A-Za-z0-9 < /dev/urandom | head -c 64 | xargs)"
+
+    cat <<EOF | mysql --host localhost --user root
+    create database $DB;
+    grant usage on $DB.* to '$DB'@'$HOST' identified by '$PASSWORD';
+    grant all privileges on $DB.* to '$DB'@'$HOST';
+    EOF
+
+    echo
+    echo "Password for user $DB is:"
+    echo
+    echo $PASSWORD
+    echo
+  '';
+  mysqlDeleteDatabase = pkgs.writeShellScriptBin "mysql-delete-database" ''
+    #!/usr/bin/env bash
+    if [ $# -lt 1 ]
+    then
+      echo "Usage: $0 <database>"
+      exit 1
+    fi
+
+    if ! [ $EUID -eq 0 ]
+    then
+      echo "Must be root!" >&2
+      exit 1
+    fi
+
+    DB="$1"
+    PASSWORD="$(tr -dc A-Za-z0-9 < /dev/urandom | head -c 64 | xargs)"
+
+    cat <<EOF | mysql --host localhost --user root
+    drop database $DB;
+    drop user '$DB';
+    EOF
+
+    echo
+    echo "Dropped database $DB!"
+    echo
+  '';
+in {
+  environment.systemPackages = [
+    mysqlCreateDatabase
+    mysqlDeleteDatabase
+  ];
+
+  services.mysql = {
+    enable = true;
+    package = pkgs.mariadb;
+    settings = {
+      mysqld = {
+        max_allowed_packet = "64M";
+      };
+    };
+  };
+
+  services.mysqlBackup.enable = true;
+  services.mysqlBackup.databases = [ "mysql" ];
+}