prepare certification files

If your etcd cluster is installed using etcdadm, you are likely to find certification files in the path /etc/etcd/pki/: ca.crt, etcdctl-etcd-client.key, etcdctl-etcd-client.crt.

If your etcd cluster is the builtin etcd in one kubernetes cluster( using kubeadm),

you can find the same files in /etc/kubernetes/pki/etcd/: ca.crt, healthcheck-client.crt, healthcheck-client.key.

Because SslContextBuilder only support a PKCS#8 private key file in PEM format, convert etcdctl-etcd-client.key to etcdctl-etcd-client.key.pem according to netty SslContextBuilder doc.

build jetcd client

        File cert = new File("ca.crt");
        File keyCertChainFile = new File("etcdctl-etcd-client.crt");
        File keyFile = new File("etcdctl-etcd-client.key.pem");
        SslContext context = GrpcSslContexts.forClient()
                .trustManager(cert)
                .keyManager(keyCertChainFile, keyFile)
                .build();
        Client client = Client.builder()
                .endpoints("https://10.168.168.66:2379")
                .sslContext(context)
                .build();

        client.getClusterClient().listMember().get().getMembers().forEach(member -> {
            logger.info("member: {}", member);
        });