7859d8c409
* Moving server performance guide to docs. * fixing broken links * updating broken link * fixing broken links
188 lines
8.5 KiB
Markdown
188 lines
8.5 KiB
Markdown
---
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layout: "docs"
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page_title: "Connect in Production"
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sidebar_current: "docs-guides-connect-production"
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description: |-
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This guide describes best practices for running Consul Connect in production.
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---
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# Running Connect in Production
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Consul Connect can secure all inter-service communication with mutual TLS. It's
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designed to work with [minimal configuration out of the
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box](https://learn.hashicorp.com/consul/getting-started/connect), however, completing the [security
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checklist](/docs/connect/security.html) and understanding the [Consul security
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model](/docs/internals/security.html) are prerequisites for production
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deployments.
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After completing this guide, you will be able to configure Connect to
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secure services. First, you will secure your Consul cluster with ACLs and
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TLS encryption. Next, you will configure Connect on the servers and host.
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Finally, you will configure your services to use Connect.
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~> Note: To complete this guide you should already have a Consul cluster
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with an appropriate number of servers and
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clients deployed according to the other reference material including the
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[deployment](/docs/guides/deployment.html) and
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[performance](/docs/install/performance.html) guides.
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The steps we need to get to a secure Connect cluster are:
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1. [Configure ACLs](#configure-acls)
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1. [Configure Agent Transport Encryption](#configure-agent-transport-encryption)
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1. [Bootstrap Connect's Certificate Authority](#bootstrap-certificate-authority)
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1. [Setup Host Firewall](#setup-host-firewall)
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1. [Configure Service Instances](#configure-service-instances)
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For existing Consul deployments, it may be necessary to incrementally adopt Connect
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service-by-service. In this case, step one and two should already be complete.
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However, we recommend reviewing all steps since the final deployment goal is to be compliant with all the security recommendations in this guide.
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## Configure ACLs
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Consul Connect's security is based on service identity. In practice, the identity
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of the service is only enforcible with sufficiently restrictive ACLs.
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This section will not replace reading the full [ACL
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guide](/docs/guides/acl.html) but will highlight the specific requirements
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Connect relies on to ensure it's security properties.
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A service's identity, in the form of an x.509 certificate, will only be issued
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to an API client that has `service:write` permission for that service. In other
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words, any client that has permission to _register_ an instance of a service
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will be able to identify as that service and access all of the resources that that
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service is allowed to access.
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A secure ACL setup must meet the following criteria.
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1. **[ACL default
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policy](/docs/agent/options.html#acl_default_policy)
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must be `deny`.** If for any reason you cannot use the default policy of
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`deny`, you must add an explicit ACL denying anonymous `service:write`. Note, in this case the Connect intention graph will also default to
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`allow` and explicit `deny` intentions will be needed to restrict service
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access. Also note that explicit rules to limit who can manage intentions are
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necessary in this case. It is assumed for the remainder of this guide that
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ACL policy defaults to `deny`.
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2. **Each service must have a unique ACL token** that is restricted to
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`service:write` only for the named service. You can review the [Securing Consul with ACLs](https://learn.hashicorp.com/consul/advanced/day-1-operations/production-acls#apply-individual-tokens-to-the-services) guide for a
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service token example. Note, it is best practices for each instance to get a unique token as described below.
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~> Individual Service Tokens: It is best practice to create a unique ACL token per service _instance_ because
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it limits the blast radius of a compromise. However, since Connect intentions manage access based only on service identity, it is
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possible to create only one ACL token per _service_ and share it between
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instances.
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In practice, managing per-instance tokens requires automated ACL provisioning,
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for example using [HashiCorp's
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Vault](https://www.vaultproject.io/docs/secrets/consul/index.html).
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## Configure Agent Transport Encryption
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Consul's gossip (UDP) and RPC (TCP) communications need to be encrypted
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otherwise attackers may be able to see ACL tokens while in flight
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between the server and client agents (RPC) or between client agent and
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application (HTTP). Certificate private keys never leave the host they
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are used on but are delivered to the application or proxy over local
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HTTP so local agent traffic should be encrypted where potentially
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untrusted parties might be able to observe localhost agent API traffic.
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Follow the [encryption guide](https://learn.hashicorp.com/consul/advanced/day-1-operations/agent-encryption) to ensure
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both gossip encryption and RPC/HTTP TLS are configured securely.
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## Bootstrap Connect's Certificate Authority
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Consul Connect comes with a built-in Certificate Authority (CA) that will
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bootstrap by default when you first [enable](https://www.consul.io/docs/agent/options.html#connect_enabled) Connect on your servers.
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To use the built-in CA, enable it in the server's configuration.
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```text
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connect {
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enabled = true
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}
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```
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This configuration change requires a Consul server restart, which you can perform one server at a time
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to maintain availability in an existing cluster.
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As soon as a server that has Connect enabled becomes the leader, it will
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bootstrap a new CA and generate it's own private key which is written to the
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Raft state.
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Alternatively, an external private key can be provided via the [CA
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configuration](/docs/connect/ca.html#specifying-a-private-key-and-root-certificate).
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~> External CAs: Connect has been designed with a pluggable CA component so external CAs can be
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integrated. For production workloads we recommend using [Vault or another external
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CA](/docs/connect/ca.html#external-ca-certificate-authority-providers) once
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available such that the root key is not stored within Consul state at all.
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## Setup Host Firewall
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In order to enable inbound connections to connect proxies, you may need to
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configure host or network firewalls to allow incoming connections to proxy
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ports.
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In addition to Consul agent's [communication
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ports](/docs/agent/options.html#ports) any
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[proxies](/docs/connect/proxies.html) will need to have
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ports open to accept incoming connections.
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If using [sidecar service
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registration](/docs/connect/proxies/sidecar-service.html) Consul will by default
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assign ports from [a configurable
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range](/docs/agent/options.html#sidecar_min_port) the default range is 21000 -
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21255. If this feature is used, the agent assumes all ports in that range are
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both free to use (no other processes listening on them) and are exposed in the
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firewall to accept connections from other service hosts.
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It is possible to prevent automated port selection by [configuring
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`sidecar_min_port` and
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`sidecar_max_port`](/docs/agent/options.html#sidecar_min_port) to both be `0`,
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forcing any sidecar service registrations to need an explicit port configured.
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It then becomes the same problem as opening ports necessary for any other
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application and might be managed by configuration management or a scheduler.
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## Configure Service Instances
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With [necessary ACL tokens](#configure-acls) in place, all service registrations
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need to have an appropriate ACL token present.
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For on-disk configuration the `token` parameter of the service definition must
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be set.
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```json
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{
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"service": {
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"name": "cassandra_db",
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"port": 9002,
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"token: "<your_token_here>"
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}
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}
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```
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For registration via the API the token is passed in the [request
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header](/api/index.html#authentication), `X-Consul-Token`, or by using the [Go
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client configuration](https://godoc.org/github.com/hashicorp/consul/api#Config).
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To avoid the overhead of a proxy, applications may [natively
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integrate](/docs/connect/native.html) with connect.
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~> Protect Application Listener: If using any kind of proxy for connect, the application must ensure no untrusted
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connections can be made to it's unprotected listening port. This is typically
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done by binding to `localhost` and only allowing loopback traffic, but may also
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be achieved using firewall rules or network namespacing.
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For examples of proxy service definitions see the [proxy
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documentation](/docs/connect/proxies.html).
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## Summary
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After securing your Consul cluster with ACLs and TLS encryption, you
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can use Connect to secure service-to-service communication. If you
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encounter any issues while setting up Consul Connect, there are
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many [community](https://www.consul.io/community.html) resources where you can find help.
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