SystemApi Class — spring-boot Architecture

Source Code

buildpack/spring-boot-buildpack-platform/src/main/java/org/springframework/boot/buildpack/platform/docker/DockerApi.java lines 534–566

	class SystemApi {

		private final DockerLog log;

		SystemApi(DockerLog log) {
			this.log = log;
		}

		/**
		 * Get the API version supported by the Docker daemon.
		 * @return the Docker daemon API version
		 */
		ApiVersion getApiVersion() {
			try {
				URI uri = new URIBuilder("/_ping").build();
				try (Response response = http().head(uri)) {
					Header apiVersionHeader = response.getHeader(API_VERSION_HEADER_NAME);
					if (apiVersionHeader != null) {
						return ApiVersion.parse(apiVersionHeader.getValue());
					}
				}
				catch (Exception ex) {
					this.log.log("Warning: Failed to determine Docker API version: " + ex.getMessage());
					// fall through to return default value
				}
				return UNKNOWN_API_VERSION;
			}
			catch (URISyntaxException ex) {
				throw new IllegalStateException(ex);
			}
		}

	}