Replicate Data to TLS-enabled Downstream Services

This document describes how to replicate data to TLS-enabled downstream services on Kubernetes.

Preparations

Before you begin, do the following preparations:

Deploy a downstream service, and enable the TLS authentication on the client.
Generate the key file required for the client to access the downstream service.

Steps

Create a Kubernetes Secret object that contains a client TLS certificate used to access the downstream service. You can get the certificate from the key file you generated for the client.
```
  kubectl create secret generic ${secret_name} --namespace=${cluster_namespace} --from-file=tls.crt=client.pem --from-file=tls.key=client-key.pem --from-file=ca.crt=ca.pem
```
Mount the certificate file to the TiCDC Pod.
- If you have not deployed a TiDB cluster yet, add the spec.ticdc.tlsClientSecretNames field to the TidbCluster CR definition, and then deploy the TiDB cluster.
- If you have already deployed a TiDB cluster, run kubectl edit tc ${cluster_name} -n ${cluster_namespace}, add the spec.tiddc.tlsClientSecretNames field, and then wait for the TiCDC pod to automatically roll over for updates.
```
apiVersion: pingcap.com/v1alpha1
kind: TidbCluster
metadata:
  name: ${cluster_name}
  namespace: ${cluster_namespace}
spec:
  # ...
  ticdc:
    baseImage: pingcap/ticdc
    version: "v5.0.1"
    # ...
    tlsClientSecretNames:
    - ${secret_name}
```
Once the TiCDC Pod is running, the created Kubernetes Secret object is mounted to the TiCDC Pod. You can get the mounted key file in the /var/lib/sink-tls/${secret_name} directory of the Pod.

Create a replication task using the cdc cli tool.

kubectl exec ${cluster_name}-ticdc-0 -- /cdc cli changefeed create --pd=https://${cluster_name}-pd:2379 --sink-uri="mysql://${user}:{$password}@${downstream_service}/?ssl-ca=/var/lib/sink-tls/${secret_name}/ca.crt&ssl-cert=/var/lib/sink-tls/${secret_name}/tls.crt&ssl-key=/var/lib/sink-tls/${secret_name}/tls.key"