hashicorp/nomad · error

invalid server.client_introduction configuration: %w

Error message

invalid server.client_introduction configuration: %w

What it means

When server.client_introduction is configured, convertServerConfig translates it into the internal ClientIntroductionConfig and calls its Validate() method. If validation fails, the underlying error is wrapped with this message and agent configuration aborts. This indicates a structurally or semantically invalid client_introduction block.

Source

Thrown at command/agent/agent.go:750

			runtime.NumCPU())
	}

	// If the operator has specified a client introduction server config block,
	// translate this into the internal server configuration object.
	if agentConfig.Server.ClientIntroduction != nil {
		if agentConfig.Server.ClientIntroduction.Enforcement != "" {
			conf.NodeIntroductionConfig.Enforcement = agentConfig.Server.ClientIntroduction.Enforcement
		}
		if agentConfig.Server.ClientIntroduction.DefaultIdentityTTL > 0 {
			conf.NodeIntroductionConfig.DefaultIdentityTTL = agentConfig.Server.ClientIntroduction.DefaultIdentityTTL
		}
		if agentConfig.Server.ClientIntroduction.MaxIdentityTTL > 0 {
			conf.NodeIntroductionConfig.MaxIdentityTTL = agentConfig.Server.ClientIntroduction.MaxIdentityTTL
		}
	}

	if err := conf.NodeIntroductionConfig.Validate(); err != nil {
		return nil, fmt.Errorf("invalid server.client_introduction configuration: %w", err)
	}

	// Copy LogFile config value
	conf.LogFile = agentConfig.LogFile

	return conf, nil
}

// serverConfig is used to generate a new server configuration struct
// for initializing a nomad server.
func (a *Agent) serverConfig() (*nomad.Config, error) {
	c, err := convertServerConfig(a.config)
	if err != nil {
		return nil, err
	}

	a.finalizeServerConfig(c)
	return c, nil

View on GitHub (pinned to 482b49bf1a)

Solutions

1. Read the wrapped cause (%w) after this message for the specific field that failed Validate().
2. Fix the offending field in the server.client_introduction block (correct address/port/format).
3. Remove the client_introduction block if the feature is not needed so defaults apply.
4. Check the Nomad version's documented schema for client_introduction.

Example fix

// before
server {
  client_introduction {
    # missing required field
  }
}
// after
server {
  client_introduction {
    required_field = "valid-value"
  }
}

cic := buildClientIntroductionConfig(agentCfg)
if err := cic.Validate(); err != nil {
  return fmt.Errorf("client_introduction invalid before agent start: %w", err)
}

When it happens

Trigger: Supplying a server.client_introduction block whose fields fail ClientIntroductionConfig.Validate() (e.g. missing required fields or malformed values) during agent startup or reload via handleReload.

Common situations: Misconfigured or incomplete client_introduction blocks copied from docs; invalid host/port fields; upgrading Nomad and introducing new client_introduction keys with wrong values.

Understand the failure class

Background: "Invalid value" and "allowed values are" config errors: what your library rejected and how to fix it — this error's family across 41 libraries.

Related errors

• wait config is nil or empty
• missing datacenter for client registration
• default_identity_ttl must be greater than 0
• max_identity_ttl must be greater than 0
• max_identity_ttl must be greater than or equal to default_id

AI-assisted analysis of hashicorp/nomad@482b49bf1a (2026-09-04). Data as JSON: /api/errors/de3a2ec6bb7b1165. Report an issue: GitHub.