hashicorp/nomad · error

missing target namespace

Error message

missing target namespace

What it means

ScalingPolicy.validateTargetHorizontal() checks that a horizontal policy's `target` map contains a non-empty `Namespace` key. Nomad horizontal policies must identify the job and group they scale via Namespace/Job/TaskGroup target keys; a missing Namespace produces this error.

Source

Thrown at nomad/structs/structs.go:6466

	}

	if p.Min < 0 {
		mErr.Errors = append(mErr.Errors,
			fmt.Errorf("minimum count must be specified and non-negative"))
	}

	return mErr.ErrorOrNil()
}

func (p *ScalingPolicy) validateTargetHorizontal() (mErr multierror.Error) {
	if len(p.Target) == 0 {
		// This is probably not a Nomad horizontal policy
		return
	}

	// Nomad horizontal policies should have Namespace, Job and TaskGroup
	if p.Target[ScalingTargetNamespace] == "" {
		mErr.Errors = append(mErr.Errors, fmt.Errorf("missing target namespace"))
	}
	if p.Target[ScalingTargetJob] == "" {
		mErr.Errors = append(mErr.Errors, fmt.Errorf("missing target job"))
	}
	if p.Target[ScalingTargetGroup] == "" {
		mErr.Errors = append(mErr.Errors, fmt.Errorf("missing target group"))
	}
	return
}

// Diff indicates whether the specification for a given scaling policy has changed
func (p *ScalingPolicy) Diff(p2 *ScalingPolicy) bool {
	copy := *p2
	copy.ID = p.ID
	copy.CreateIndex = p.CreateIndex
	copy.ModifyIndex = p.ModifyIndex
	return !reflect.DeepEqual(*p, copy)
}

View on GitHub (pinned to 482b49bf1a)

Solutions

1. Add `namespace = "default"` (or the correct namespace) inside the policy's target block.
2. When using the API, set Target["Namespace"] in the policy JSON.
3. Validate with `nomad job validate` or the scaling policy validate endpoint.

Example fix

// before
policy {
  type = "horizontal"
  target {}
}
// after
policy {
  type = "horizontal"
  target {
    namespace = "default"
    job       = "web"
    group     = "frontend"
  }
}

required := []string{"Namespace", "Job", "TaskGroup"}
for _, k := range required {
	if policy.Target[k] == "" {
		return fmt.Errorf("horizontal policy target missing %s", k)
	}
}

When it happens

Trigger: Submitting a scaling policy whose `policy { target { } }` block omits `namespace`, or an API object with Target["Namespace"] == "", when the policy type is horizontal.

Common situations: Hand-written policy blocks missing the target stanza; external autoscaler tooling building Target maps without the Namespace key; cluster namespace renamed but policy not updated (though omission, not wrong value, triggers this).

Understand the failure class

Background: "missing required argument" and "the following required arguments were not provided": what required-argument errors mean and how to fix them — this error's family across 20 libraries.

Related errors

• missing target job
• missing target group
• missing scaling policy type
• maximum count must be specified and non-negative
• maximum count must not be less than minimum count

AI-assisted analysis of hashicorp/nomad@482b49bf1a (2026-09-04). Data as JSON: /api/errors/f067157d9605219b. Report an issue: GitHub.