homelab-nomad/service.nomad

# Vars
# name = string*
# image = string*
# service_port = int
# ingress = bool
# sticky_disk = bool
# args = json(list[str])
# resources = dict(cpu = int, mem = int)
# env = json(dict(str: any))
# ingress_middlewares = json(list(str))
# templates = json(list(dict(
#   data = str,
#   dest = str,
#   change_mode = str,
#   change_signal = str,
#   left_delimiter = str,
#   right_delimiter = str,
#   mount = bool
# )))
# host_volumes = json(list(dict(
#   name = str,
#   dest = str,
#   read_only = bool,
# )))
# healthcheck = "/"
# upstreams = json(list(dict(
#   destination_name = str,
#   local_bind_port = int
# )))
# mysql = bool
# redis = bool
# vault = bool
# mysql_bootstrap = json(dict(
#   vault_key = str
#   db_name = str
#   db_name_key = str
#   db_user = str
#   db_user_key = str
#   db_pass = str
#   db_pass_key = str
# ))
job "[[.name]]" {
  region = "global"
  datacenters = ["dc1"]

  type = "service"

  group "[[.name]]" {
    [[ with .count ]]count = [[ . ]][[ end ]]
    network {
      mode = "bridge"
      [[ if not (empty .service_port) -]]
      port "main" {
        host_network = "wesher"
        to = [[ .service_port ]]
      }
      [[ end -]]
    }

    [[ if default false .sticky_disk ]]
    ephemeral_disk {
      migrate = true
      sticky = true
    }
    [[ end ]]

    [[ with .host_volumes -]]
    [[ range $v := . | parseJSON -]]
    volume "[[ $v.name ]]" {
      type = "host"
      read_only = [[ $v.read_only ]]
      source = "[[ $v.name ]]"
    }
    [[ end ]]
    [[ end -]]

    [[ if not (empty .service_port) ]]
    service {
      name = "[[.name | replace "_" "-"]]"
      provider = "nomad"
      port = "main"

      [[ if not (eq .healthcheck "") -]]
      check {
        type = "http"
        path = "[[ or .healthcheck "/" ]]"
        port = "main"
        interval = "10s"
        timeout = "10s"
      }
      [[ end -]]

      tags = [
        [[ if default false .ingress -]]
        "traefik.enable=true",
        "traefik.http.routers.[[.name]].entryPoints=websecure",
        [[ if not (empty .ingress_rule) -]]
        "traefik.http.routers.[[.name]].rule=[[.ingress_rule]]",
        [[ end -]]
        [[ with .ingress_middlewares -]][[ range $m := . | parseJSON -]]
        "traefik.http.routers.[[$.name]].middlewares=[[ $m ]]",
        [[ end -]][[ end -]]
        [[ end -]]
      ]
    }
    [[ end -]]

    task "[[.name]]" {
      driver = "docker"

      config {
        image = "[[.image]]"
        [[ with .service_port -]]
        ports = ["main"]
        [[ end -]]
        [[ with .args -]]
        args = [[ . ]]
        [[ end -]]

        [[ with .templates -]]
        [[ range $t := . | parseJSON -]]
        [[ if and (default true $t.mount) (not (default false $t.env))  -]]
        mount {
          type = "bind"
          target = "[[ $t.dest ]]"
          source = "[[ default "local/" $t.dest_prefix ]][[ $t.dest ]]"
        }
        [[ end -]]
        [[ end ]]
        [[ end -]]
      }

      [[ with .env -]]
      env = {
        [[ range $k, $v := . | parseJSON -]]
        "[[$k]]" = "[[$v]]"
        [[ end -]]
      }
      [[ end -]]

      [[ with .host_volumes -]]
      [[ range $v := . | parseJSON -]]
      volume_mount {
        volume = "[[ $v.name ]]"
        destination = "[[ $v.dest ]]"
        read_only = [[ $v.read_only ]]
      }
      [[ end ]]
      [[ end -]]

      [[ with .templates -]]
      [[ range $t :=  . | parseJSON -]]
      template {
        data = <<EOF
[[ $t.data ]]
EOF
        destination = "[[ default "local/" $t.dest_prefix ]][[ $t.dest ]]"
        [[ with $t.left_delimiter ]]left_delimiter = "[[ . ]]"[[ end -]]
        [[ with $t.right_delimiter ]]right_delimiter = "[[ . ]]"[[ end -]]
        [[ with $t.change_mode ]]change_mode = "[[ . ]]"[[ end -]]
        [[ with $t.change_signal ]]change_signal = "[[ . ]]"[[ end -]]
        [[ with $t.env ]]env = [[ . ]][[ end ]]
      }
      [[ end -]]
      [[ end -]]

      [[ with .resources -]]
      resources {
        cpu = [[ .cpu ]]
        memory = [[ .memory ]]
      }
      [[ end -]]
    }
    [[ with .mysql_bootstrap ]][[ with . | parseJSON ]]
    task "[[$.name]]-bootstrap" {
      driver = "docker"

      lifecycle {
        hook = "prestart"
        sidecar = false
      }

      config {
        image = "mariadb:10"
        args = [
          "/bin/bash",
          "-c",
          "/usr/bin/mysql --defaults-extra-file=${NOMAD_SECRETS_DIR}/my.cnf < ${NOMAD_SECRETS_DIR}/bootstrap.sql",
        ]
      }

      vault {
        policies = [
          "access-tables",
          "nomad-task",
        ]
      }

      template {
        data = <<EOF
[client]
{{ range nomadService 1 (env "NOMAD_ALLOC_ID") "mysql-server" -}}
host={{ .Address }}
port={{ .Port }}
{{ end -}}
user=root
# TODO: Use via lesser scoped access
{{ with nomadVar "nomad/jobs" -}}
password={{ .mysql_root_password }}
{{ end -}}
        EOF
        destination = "${NOMAD_SECRETS_DIR}/my.cnf"
      }

      template {
        data = <<EOF
{{ with nomadVar "[[.vault_key]]" -}}
CREATE DATABASE IF NOT EXISTS `{{ .[[ default "db_name" .db_name_key ]] }}`
  CHARACTER SET = 'utf8mb4'
  COLLATE = 'utf8mb4_unicode_ci';
CREATE USER IF NOT EXISTS '{{ .[[ default "db_user" .db_user_key ]] }}'@'%'
  IDENTIFIED BY '{{ .[[ default "db_pass" .db_pass_key ]] }}';
GRANT ALL ON `{{ .[[ default "db_name" .db_name_key ]] }}`.* to '{{ .[[ default "db_user" .db_user_key ]] }}'@'%';
{{ end -}}
{{ end -}}
        EOF
        destination = "${NOMAD_SECRETS_DIR}/bootstrap.sql"
      }

      resources {
        cpu = 50
        memory = 50
      }
    }
    [[ end -]][[ end -]]
  }
}