What causes "check type %+q not valid" in hashicorp/nomad?

Correct the check type to a supported value: http, tcp, grpc, script, or ttl.

check type %+q not valid

Error message

check type %+q not valid

What it means

Nomad validates each service check's type while translating to a Consul check registration. Only known check types (http, tcp, grpc, script, ttl, etc. per the switch) are supported; anything else falls to the default case and is rejected before being sent to Consul.

Source

Thrown at command/agent/consul/service_client.go:2060

	case structs.ServiceCheckTCP:
		chkReg.TCP = net.JoinHostPort(host, strconv.Itoa(port))

	case structs.ServiceCheckScript:
		chkReg.TTL = (check.Interval + ttlCheckBuffer).String()
		// As of Consul 1.0.0 setting TTL and Interval is a 400
		chkReg.Interval = ""

	case structs.ServiceCheckGRPC:
		chkReg.GRPC = fmt.Sprintf("%s/%s", net.JoinHostPort(host, strconv.Itoa(port)), check.GRPCService)
		chkReg.GRPCUseTLS = check.GRPCUseTLS
		if check.TLSSkipVerify {
			chkReg.TLSSkipVerify = true
		}
		chkReg.TLSServerName = check.TLSServerName

	default:
		return nil, fmt.Errorf("check type %+q not valid", check.Type)
	}
	return &chkReg, nil
}

// isNomadClient returns true if id represents a Nomad Client registration.
func isNomadClient(id string) bool {
	return strings.HasPrefix(id, nomadClientPrefix)
}

// isNomadServer returns true if id represents a Nomad Server registration.
func isNomadServer(id string) bool {
	return strings.HasPrefix(id, nomadServerPrefix)
}

// isNomadAgent returns true if id represents a Nomad Client or Server registration.
func isNomadAgent(id string) bool {
	return isNomadClient(id) || isNomadServer(id)
}

View on GitHub (pinned to 482b49bf1a)

Solutions

Correct the check type to a supported value: http, tcp, grpc, script, or ttl.
Check type spelling and case (must be lowercase).
If you need TLS http checks, use type="http" with tls_skip_verify/tls_server_name, not type="https".
Upgrade Nomad if you need a check type introduced in a newer release.

Example fix

// before
check { type = "https", path = "/health" }
// after
check { type = "http", path = "/health", tls_skip_verify = true }

Defensive patterns

Strategy: validation

Validate before calling

var validCheckTypes = map[string]bool{"http": true, "tcp": true, "grpc": true, "script": true, "ttl": true}
if !validCheckTypes[strings.ToLower(check.Type)] {
  return fmt.Errorf("unsupported check type %q", check.Type)
}

Type guard

func isValidCheckType(t string) bool {
  switch t {
  case "http", "tcp", "grpc", "script", "ttl":
    return true
  }
  return false
}

Try / catch

try {
  nomad.jobRegister(job)
} catch err {
  if strings.Contains(err.Error(), "not valid") && strings.Contains(err.Error(), "check type") {
    log.Error("fix check type in job spec", "err", err)
  }
}

Prevention

Validate job specs with `nomad job validate` in CI pipelines.
Keep a shared HCL module with whitelisted check types.
Never copy raw Consul check definitions into Nomad job files without translating types.
Confirm type is lowercase in the job file.

When it happens

Trigger: Submitting a job whose service check `type` field is misspelled or unsupported (e.g. type="https" or type="HTTP" uppercase) so it matches none of the switch cases in makeAgentServiceCheck.

Common situations: Typo in HCL check type; copying Consul-native check types Nomad doesn't accept; older Nomad version lacking a newer check type added later.

Understand the failure class

Background: Invalid enum value errors: "Unknown type", "Invalid scope", "must be one of" — when a string is not on the library's allowed list — this error's family across 23 libraries.

Related errors

AI-assisted analysis of hashicorp/nomad@482b49bf1a (2026-09-04). Data as JSON: /api/errors/121246f709607953. Report an issue: GitHub.