Validation error when submitting task with template.change_mode = "script"

[RobbieFernandez]

Nomad version

Output from nomad version
Nomad v1.3.5 (1359c25)

I am submitting the job via nomad-pack:
Nomad Pack v0.0.1-techpreview.3 (3b4163b)

Operating system and Environment details

Ubuntu 22.04 LTS

Issue

I'm attempting to submit a Nomad task where a template generates an nginx config file. I'm trying to use the change_mode = "script" and change_script:

        data = <<-EOH
          upstream nextjs {
            {{ range nomadService "nextjs" }}
            server {{ .Address }}:{{ .Port }};
            {{- end }}
          }

          server {
            server_name _;
            listen 80;
            location / {
              proxy_pass http://nextjs;
            }
          }
        EOH

        destination = "local/nginx.conf"
        change_mode = "script"
        change_script {
          command       = "/usr/sbin/nginx"
          args          = ["-s", "reload"]
          timeout       = "5s"
          fail_on_error = true
        }
      }

I am getting the following error complaining that change_script must be set, which as you can see above it is:

  Job 'afid-backend' in pack deployment 'afid' registered successfully
! Failed To Register Job

	Error:   1 error occurred:
	* Task group nextjs-balancer validation failed: 1 error occurred:
	* Task nextjs-balancer validation failed: 1 error occurred:
	* Template 1 validation failed: 1 error occurred:
	* must specify change script configuration value when change mode is script








	Type:    *v1.APIError
	Context: 
	         - Registry Name: <<local folder>>
	         - Pack Name: afid
	         - Pack Ref: <<none>>
	         - Pack Path: /home/robbie/Projects/afid-deploy/nomad/packs/afid
	         - Deployment Name: afid
	         - Template Name: afid/templates/afid-frontend.nomad.tpl
	         - Job Name: afid-frontend

I'm submitting the job with nomad-pack, so I'm not sure if that could be causing any issues too. Happy to move the issue to the nomad-pack repo if that is the case. I am also not sure if this is related to this issue: #14367 but it seems that should be fixed in the version of Nomad I'm using.

Setting the change_mode to "restart" does work.

Reproduction steps

Submit job with template change_mode "script", and a change_script set (possibly only through nomad-pack?)

Expected Result

Job should be validated and sent correctly.

Actual Result

A validation error is raised.

Job file (if appropriate)

job "afid-frontend" {
  datacenters = ["dc1"]

  group "nextjs" {
    count = [[ .afid.resources.nextjs.count ]]

    network {
      mode = "bridge"

      port "nextjs" {
        to = 3000
      }
    }

    service {
      name     = "nextjs"
      port     = "nextjs"
      provider = "nomad"
    }

    task "nextjs" {
      template {
        data = <<-EOH
        {{$allocID := env "NOMAD_ALLOC_ID" -}}
        {{range nomadService 1 $allocID "afid-web"}}
        APP_URL=http://{{.Address}}:{{.Port}}
        {{- end}}
        EOH

        destination = "local/nextjs.env"
        env         = true
        change_mode = "restart"
      }

      driver = "docker"

      config {
        image = "privaterepo/image" # (Redacted for this issue)
        ports = ["nextjs"]
      }

      resources {
        memory = [[ .afid.resources.nextjs.memory ]]
        cpu    = [[ .afid.resources.nextjs.cpu ]]
      }
    }
  }

  group "nextjs-balancer" {
    count = 1

    network {
      mode = "bridge"

      port "http" {
        to = 80
      }
    }

    service {
      name     = "nextjs-balancer"
      port     = "http"
      provider = "nomad"
    }

    task "nextjs-balancer" {
      template {
        data = <<-EOH
          upstream nextjs {
            {{ range nomadService "nextjs" }}
            server {{ .Address }}:{{ .Port }};
            {{- end }}
          }

          server {
            server_name _;
            listen 80;
            location / {
              proxy_pass http://nextjs;
            }
          }
        EOH

        destination = "local/nginx.conf"
        change_mode = "script"
        change_script {
          command       = "/usr/sbin/nginx"
          args          = ["-s", "reload"]
          timeout       = "5s"
          fail_on_error = true
        }
      }

      driver = "docker"

      config {
        image = "nginx:1.23.1-alpine"
        ports = ["http"]

        volumes = [
          "local/nginx.conf:/etc/nginx/conf.d/default.conf"
        ]
      }
    }
  }
}

Nomad Server logs (if appropriate)

2022-09-07T04:58:04.036Z [ERROR] http: request failed: method=POST path=/v1/jobs?region=global
  error=
  | 1 error occurred:
  | 	* Task group nextjs-balancer validation failed: 1 error occurred:
  | 	* Task nextjs-balancer validation failed: 1 error occurred:
  | 	* Template 1 validation failed: 1 error occurred:
  | 	* must specify change script configuration value when change mode is script
  | 
  | 
  | 
  | 
  | 
  | 
  | 
   code=500

Nomad Client logs (if appropriate)

[DerekStrickland]

Hi @RobbieFernandez. Thanks for reporting this issue. I'll take a look at this, and thanks for pointing out the Pack aspect.

[pkazmierczak]

Hey @RobbieFernandez, it was indeed an issue with Nomad Pack, its API dependency package wasn't updated along with the changes we introduced in Nomad. Apologies—I overlooked this while working on the feature.

[github-actions]

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