Store mysql root password in a Nomad variable.

services/mysql.hcl

@@ -14,13 +14,16 @@ job "mysql" {
       driver = "docker"
 
       config {
-        image = "mysql:8.1"
+        image = "mysql:8.2"
         ports = ["db"]
-        volumes = [ "/data/compute/appdata/mysql:/var/lib/mysql" ]
+        volumes = [
+          "/data/compute/appdata/mysql:/var/lib/mysql",
+          "/data/compute/db-backups/mysql:/backup",
+        ]
       }
 
       env {
-        MYSQL_ROOT_PASSWORD = "${var.mysql_root_password}"
+        MYSQL_ROOT_PASSWORD = "{{ with nomadVar \"nomad/jobs/mysql\" }}{{ .root_password }}{{ end }}"
       }
 
       service {
@@ -61,8 +64,3 @@ job "mysql" {
     }
   }
 }
-
-variable "mysql_root_password" {
-  type = string
-  default = "wiochohv8foR9eDo5ol5"
-}