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