Service Mesh Configuration Overview

There are many configuration options exposed for Consul service mesh. The only option that must be set is the connect.enabled option on Consul servers to enable Consul service mesh. All other configurations are optional and have defaults suitable for many environments.

The noun connect is used throughout this documentation to refer to the connect subsystem that provides Consul's service mesh capabilities. Where you encounter the noun connect, it is usually functionality specific to service mesh.

Agent configuration

Begin by enabling service mesh for your Consul cluster. By default, service is disabled. Enabling service mesh requires changing the configuration of only your Consul servers (not client agents). To enable service mesh, add the following to a new or existing server configuration file. In an existing cluster, this configuration change requires a Consul server restart, which you can perform one server at a time to maintain availability. In HCL:

connect {
  enabled = true
}

{
  "connect": {
    "enabled": true
  }
}

This will enable service mesh and configure your Consul cluster to use the built-in certificate authority for creating and managing certificates. You may also configure Consul to use an external certificate management system, such as Vault.

Services and proxies may always register with service mesh settings, but unless service mesh is enabled on the server agents, their attempts to communicate will fail because they have no means to obtain or verify service mesh TLS certificates.

Other optional service mesh configurations that you can set in the server configuration file include:

• certificate authority settings
• token replication
• dev mode
• server host name verification

If you would like to use Envoy as your service mesh proxy you will need to enable gRPC.

Additionally if you plan on using the observability features of Consul service mesh, it can be convenient to configure your proxies and services using configuration entries which you can interact with using the CLI or API, or by creating configuration entry files. You will want to enable centralized service configuration on clients, which allows each service's proxy configuration to be managed centrally via API.

Centralized proxy and service configuration

If your network contains many instances of the same service and many colocated sidecar proxies, you can specify global settings for proxies or services in Configuration Entries. You can override the centralized configurations for individual proxy instances in their sidecar service definitions, and the default protocols for service instances in their service definitions.

Schedulers

Consul service mesh is especially useful if you are using an orchestrator like Nomad or Kubernetes, because these orchestrators can deploy thousands of service instances which frequently move hosts. Sidecars for each service can be configured through these schedulers, and in some cases they can automate Consul configuration, sidecar deployment, and service registration.

Nomad

Consul service mesh can be used with Nomad to provide secure service-to-service communication between Nomad jobs and task groups. The ability to use the dynamic port feature of Nomad makes Consul service mesh particularly easy to use. Learn about how to configure Consul service mesh on Nomad by reading the integration documentation.

Kubernetes

The Consul Helm chart can automate much of Consul's service mesh configuration, and makes it easy to automatically inject Envoy sidecars into new pods when they are deployed. Learn about the Helm chart in general, or if you are already familiar with it, check out its service mesh specific configurations.