APM agent TLS communication

edit

TLS is disabled by default. When TLS is enabled for APM Server inbound communication, agents will verify the identity of the APM Server by authenticating its certificate.

When TLS is enabled, a certificate and corresponding private key are required. The certificate and private key can either be issued by a trusted certificate authority (CA) or be self-signed.

Use a self-signed certificate
edit
Step 1: Create a self-signed certificate
edit

The Elasticsearch distribution offers the certutil tool for the creation of self-signed certificates:

  1. Create a CA: ./bin/elasticsearch-certutil ca --pem. You’ll be prompted to enter the desired location of the output zip archive containing the certificate and the private key.
  2. Extract the contents of the CA archive.
  3. Create the self-signed certificate: ./bin/elasticsearch-certutil cert --ca-cert <path-to-ca-crt>/ca.crt --ca-key <path-to-ca-key>/ca.key --pem --name localhost
  4. Extract the certificate and key from the resulted zip archive.
Step 2: Configure the APM Server
edit

Enable TLS and configure the APM Server to point to the extracted certificate and key:

Enable TLS in the APM integration settings and use the SSL/TLS input settings to set the path to the server certificate and key.

Step 3: Configure APM agents
edit

When the APM server uses a certificate that is not chained to a publicly-trusted certificate (e.g. self-signed), additional configuration is required in the APM agent:

We do not recommend disabling APM agent verification of the server’s certificate, but it is possible:

Client certificate authentication
edit

APM Server does not require agents to provide a certificate for authentication, and there is no dedicated support for SSL/TLS client certificate authentication in Elastic’s backend agents.