Pot task Driver

Name: pot-task-driver

The Pot task driver provides an interface for using pot for dynamically running applications inside a FreeBSD Jail. You can download the external pot-task-driver here.

Complete job example

job "example" {
  region = "global"
  datacenters = ["dc1"]
  type        = "service"

  group "group1" {
    count = 1
    
    network {
      port "http" {}
    } 

    task "task1" {
      driver = "pot"
      
      service {
        tags = ["pot-jail", "metrics"]
        name = "pot-example"
        port = "http"
       
         check {
            type     = "tcp"
            name     = "http"
            interval = "5s"
            timeout  = "2s"
          }
      }


      config {
        image = "https://pot-registry.zapto.org/registry/"
        pot = "FBSD121-nginx"
        tag = "1.2"
        command = "nginx"
        args = ["-g","'daemon off;'"]
        port_map = { 
          http = "80"
        }
        network_mode = "host"
        copy = [ "/tmp/test.txt:/root/test.txt", "/tmp/test2.txt:/root/test2.txt" ]
        mount = [ "/tmp/test:/root/test", "/tmp/test2:/root/test2" ]
        mount_read_only = [ "/tmp/test2:/root/test2" ] 
      }
      
      resources {
        cpu = 200
        memory = 128
      }
    }
  }
}

Task Configuration

task "nginx-pot" {
    driver = "pot"

    config {
      image = "https://pot-registry.zapto.org/registry/"
      pot = "FBSD121-nginx"
      tag = "1.2"
      command = "nginx"
      args = ["-g","'daemon off;'"]
      network_mode = "public-bridge" 
      port_map = {
        http = "80"
      }
      copy = [
        "/root/index.html:/usr/local/www/nginx-dist/index.html",
        "/root/nginx.conf:/usr/local/etc/nginx/nginx.conf"
      ]
      mount = [ 
        "/tmp/test:/root/test",  
      ]
      mount_read_only = [
        "/tmp/test2:/root/test2"
      ]
   }
}

The pot task driver supports the following parameters:

• image - The url for the http registry from where to get the image.

• pot - Name of the image in the registry.

• tag - Version of the image.

• commad - (Optional) Command that is going to be executed once the jail is started.

• args - (Optional. Depends on commad) Array of arguments to append to the command.

• network_mode - (Optional) Defines the network mode of the pot. Default: "public-bridge"

  Possible values are:

  "public-bridge" pot creates an internal virtual network with a NAT table where all traffic is going to be sent.

  "host" pot bounds the jail directly to a host port.

• port_map - (Optional) Sets the port on which the application is listening inside of the jail. If not set, the application will inherit the port configuration from the image.

• copy - (Optional) Copies a file from the host machine to the pot jail in the given directory.

• mount - (Optional) Mounts a read/write folder from the host machine to the pot jail.

• mount_read_only - (Optional) Mounts a read only directory inside the pot jail.

Client Requirements

pot-task-driver requires the following:

• 64-bit FreeBSD 12.0-RELEASE host .
• The FreeBSD's Nomad binary (available as a package).
• The pot-task-driver binary placed in the plugin_dir directory.
• Installing pot and following the install guide.
• Webserver from where to serve the images. (simple file server)
• Following lines need to be included in your rc.conf

nomad_user="root"
nomad_env="PATH=/usr/local/bin:/usr/local/sbin:/usr/bin:/usr/sbin:/sbin:/bin"