homelab-nomad/services/service/service_template.nomad

job "${name}" {
  region = "global"
  datacenters = ["dc1"]

  type = "service"

  group "${name}" {
    network {
      mode = "bridge"
      %{ if service_port != null ~}
      port "main" {
        %{ if ingress }
        host_network = "wgoverlay"
        %{~ endif }
        to = ${service_port}
      }
      %{ endif }
    }

    %{ if length(group_meta) > 0 }
    meta = {
      %{ for k, v in group_meta }
      ${k} = ${jsonencode(v)}
      %{ endfor }
    }
    %{~ endif }
    %{ if sticky_disk }
    ephemeral_disk {
      migrate = true
      sticky = true
    }
    %{~ endif }
    %{ for host_volume in host_volumes }
    volume "${host_volume.name}" {
      type = "host"
      read_only = ${host_volume.read_only}
      source = "${host_volume.name}"
    }
    %{ endfor }
    %{ if service_port != null ~}
    service {
      name = "${replace(name, "_", "-")}"
      provider = "nomad"
      port = "main"

      tags = [
        # TODO: Rename metrics_port_name to something like "prometheus_scrape"
        %{ if metrics_port_name != null }
        "prometheus.scrape",
        %{ endif }
        %{ if ingress }
        "traefik.enable=true",
        "traefik.http.routers.${name}.entryPoints=websecure",
        %{ if try(ingress_rule, null) != null ~}
        "traefik.http.routers.${name}.rule=${ingress_rule}",
        %{ endif ~}
        %{ for middleware in ingress_middlewares ~}
        "traefik.http.routers.${name}.middlewares=${middleware}",
        %{~ endfor }
        %{~ endif }
      ]
    }

    %{ endif ~}
    task "${name}" {
      driver = "docker"

      %{ if length(meta) > 0 ~}
      meta = {
        %{ for k, v in meta ~}
        ${k} = ${jsonencode(v)}
        %{ endfor ~}
      }

      %{ endif ~}
      config {
        image = "${image}"
        %{if image_pull_timeout != null ~}
        image_pull_timeout = "${image_pull_timeout}"
        %{ endif ~}
        %{ if service_port != null ~}
        ports = ["main"]
        %{ endif ~}
        %{ if length(try(args, [])) > 0 ~}
        args = ${jsonencode(args)}
        %{ endif ~}
        %{ for template in templates ~}
        %{ if template.mount && !template.env ~}

        mount {
          type = "bind"
          target = "${template.dest}"
          source = "${template.dest_prefix}/${template.dest}"
        }
        %{ endif ~}
        %{ endfor ~}
      }
      %{ if length(env) > 0 ~}

      env = {
        %{ for k, v in env ~}
        "${k}" = "${v}"
        %{ endfor }
      }
      %{ endif ~}
      %{ for volume in host_volumes ~}

      volume_mount {
        volume = "${volume.name}"
        destination = "${volume.dest}"
        read_only = ${volume.read_only}
      }
      %{ endfor ~}
      %{ for template in templates ~}

      template {
        data = <<EOF
${template.data}
EOF
        destination = "${coalesce(template.dest_prefix, "$${NOMAD_TASK_DIR}")}/${template.dest}"
        %{ if template.left_delimiter != null }left_delimiter = "${template.left_delimiter}"%{ endif }
        %{ if template.right_delimiter != null }right_delimiter = "${template.right_delimiter}"%{ endif }
        %{ if template.change_mode != null }change_mode = "${template.change_mode}"%{ endif }
        %{ if template.change_signal != null }change_signal = "${template.change_signal}"%{ endif }
        %{ if template.env != null }env = ${template.env}%{ endif }
      }
      %{ endfor ~}
      %{ if resources != null }

      resources {
        cpu = ${resources.cpu}
        memory = ${resources.memory}
        %{ if resources.memory_max != null }memory_max = ${resources.memory_max}%{ endif }
      }
      %{~ endif }
    }
    %{ if mysql_bootstrap != null }
    task "${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 "${mysql_bootstrap.vault_key}" -}}
CREATE DATABASE IF NOT EXISTS `{{ .${mysql_bootstrap.db_name_key} }}`
  CHARACTER SET = 'utf8mb4'
  COLLATE = 'utf8mb4_unicode_ci';
CREATE USER IF NOT EXISTS '{{ .${mysql_bootstrap.db_user_key} }}'@'%'
  IDENTIFIED BY '{{ .${mysql_bootstrap.db_pass_key} }}';
GRANT ALL ON `{{ .${mysql_bootstrap.db_name_key} }}`.*
  TO '{{ .${mysql_bootstrap.db_user_key} }}'@'%';
# TODO: Optionally grant ro access to ro user
{{ else -}}
SELECT 'NOOP';
{{ end -}}
        EOF
        destination = "$${NOMAD_SECRETS_DIR}/bootstrap.sql"
      }

      resources {
        cpu = 50
        memory = 50
      }
    }
    %{ endif }
  }
}