Polish Docker client exception handling

Author: scottfrederick

spring-boot-project/spring-boot-tools/spring-boot-buildpack-platform/src/main/java/org/springframework/boot/buildpack/platform/docker/HttpClientHttp.java

@@ -48,6 +48,7 @@
  *
  * @author Phillip Webb
  * @author Mike Smithson
+ * @author Scott Frederick
  */
 class HttpClientHttp implements Http {
 
@@ -129,9 +130,8 @@ private Response execute(HttpEntityEnclosingRequestBase request, String contentT
 	}
 
 	private Response execute(HttpUriRequest request) {
-		CloseableHttpResponse response;
 		try {
-			response = this.client.execute(request);
+			CloseableHttpResponse response = this.client.execute(request);
 			StatusLine statusLine = response.getStatusLine();
 			int statusCode = statusLine.getStatusCode();
 			HttpEntity entity = response.getEntity();
@@ -143,15 +143,11 @@ private Response execute(HttpUriRequest request) {
 			if (statusCode == 500) {
 				throw new DockerException(request.getURI(), statusCode, statusLine.getReasonPhrase(), null);
 			}
+			return new HttpClientResponse(response);
 		}
 		catch (IOException ioe) {
-			StringWriter stringWriter = new StringWriter();
-			PrintWriter printWriter = new PrintWriter(stringWriter);
-			ioe.printStackTrace(printWriter);
-			throw new DockerException(request.getURI(), 500, stringWriter.toString(), null);
+			throw new DockerException(request.getURI(), 500, ioe.getMessage(), null);
 		}
-
-		return new HttpClientResponse(response);
 	}
 
 	/**

spring-boot-project/spring-boot-tools/spring-boot-buildpack-platform/src/test/java/org/springframework/boot/buildpack/platform/docker/HttpClientHttpTests.java

@@ -54,6 +54,7 @@
  *
  * @author Phillip Webb
  * @author Mike Smithson
+ * @author Scott Frederick
  */
 class HttpClientHttpTests {
 
@@ -186,11 +187,12 @@ void executeWhenResposeIsIn500RangeShouldThrowDockerException() {
 	}
 
 	@Test
-	void executeWhenClientExecutesRequestThrowsIOExceptionRethrowsAsDockerException() throws IOException {
-		given(this.client.execute(any())).willThrow(IOException.class);
+	void executeWhenClientThrowsIOExceptionRethrowsAsDockerException() throws IOException {
+		given(this.client.execute(any())).willThrow(new IOException("test IO exception"));
 		assertThatExceptionOfType(DockerException.class).isThrownBy(() -> this.http.get(this.uri))
-				.satisfies((ex) -> assertThat(ex.getErrors()).isNull()).satisfies(DockerException::getStatusCode)
-				.withMessageContaining("500").satisfies((ex) -> assertThat(ex.getReasonPhrase())).isNotNull();
+				.satisfies((ex) -> assertThat(ex.getErrors()).isNull())
+				.satisfies(DockerException::getStatusCode).withMessageContaining("500")
+				.satisfies((ex) -> assertThat(ex.getReasonPhrase()).contains("test IO exception"));
 	}
 
 	private String writeToString(HttpEntity entity) throws IOException {