Application.java

@Bean
public RestTemplate k8sRestTemplate(K8sConfig k8sConfig) {

	RestTemplate restTemplate = new RestTemplate();

	Path caCertFile = Paths.get(k8sConfig.getCaCertPath());

	if (Files.exists(caCertFile) && Files.isRegularFile(caCertFile)) {
		SSLContext sslContext = SslUtils.createSslContextFromCertFile(caCertFile);
		CloseableHttpClient httpsClient = HttpClients.custom().useSystemProperties().setSSLContext(sslContext).build();
		restTemplate.setRequestFactory(new HttpComponentsClientHttpRequestFactory(httpsClient));

	} else {
		LOGGER.warn("Certificate file {} is not found, Kubernetes api client will not be configured to use HTTPS protocol.", caCertFile.toString());
		restTemplate.setRequestFactory(new SimpleClientHttpRequestFactory());
	}

	return restTemplate;
}