Fixed buffering issue when container-logging to S3

src/main/java/eu/openanalytics/containerproxy/log/S3LogStorage.java

@@ -66,10 +66,17 @@ public void initialize() throws IOException {
 		String endpoint = environment.getProperty("proxy.container-log-s3-endpoint", "https://s3-eu-west-1.amazonaws.com");
 		enableSSE = Boolean.valueOf(environment.getProperty("proxy.container-log-s3-sse", "false"));
 
-		String subPath = containerLogPath.substring("s3://".length());
+		String subPath = containerLogPath.substring("s3://".length()).trim();
+		if (subPath.endsWith("/")) subPath = subPath.substring(0, subPath.length() - 1);
+
 		int bucketPathIndex = subPath.indexOf("/");
-		bucketName = subPath.substring(0, bucketPathIndex);
-		bucketPath = subPath.substring(bucketPathIndex + 1);
+		if (bucketPathIndex == -1) {
+			bucketName = subPath;
+			bucketPath = "";
+		} else {
+			bucketName = subPath.substring(0, bucketPathIndex);
+			bucketPath = subPath.substring(bucketPathIndex + 1) + "/";
+		}
 
 		s3 = AmazonS3ClientBuilder.standard()
 				.withEndpointConfiguration(new EndpointConfiguration(endpoint, null))
@@ -87,7 +94,8 @@ public OutputStream[] createOutputStreams(Proxy proxy) throws IOException {
 		OutputStream[] streams = new OutputStream[2];
 		for (int i = 0; i < streams.length; i++) {
 			String fileName = paths[i].substring(paths[i].lastIndexOf("/") + 1);
-			streams[i] = new BufferedOutputStream(new S3OutputStream(bucketPath + "/" + fileName), 1024*1024);
+			// TODO kubernetes never flushes. So perform timed flushes, and also flush upon container shutdown
+			streams[i] = new BufferedOutputStream(new S3OutputStream(bucketPath + fileName), 1024*1024);
 		}
 		return streams;
 	}

src/main/java/eu/openanalytics/containerproxy/service/LogService.java

@@ -46,6 +46,8 @@ public class LogService {
 	private boolean loggingEnabled;
 	private Logger log = LogManager.getLogger(LogService.class);
 
+	private static final String PARAM_STREAMS = "streams";
+
 	@Inject
 	Environment environment;
 
@@ -85,15 +87,36 @@ public void attachToOutput(Proxy proxy, BiConsumer<OutputStream, OutputStream> o
 				if (streams == null || streams.length < 2) {
 					log.error("Failed to attach logging of proxy " + proxy.getId() + ": no output streams defined");
 				} else {
+					proxy.getContainers().get(0).getParameters().put(PARAM_STREAMS, streams);
+					if (log.isDebugEnabled()) log.debug("Container logging started for proxy " + proxy.getId());
 					// Note that this call will block until the container is stopped.
 					outputAttacher.accept(streams[0], streams[1]);
 				}
 			} catch (Exception e) {
 				log.error("Failed to attach logging of proxy " + proxy.getId(), e);
 			}
+			if (log.isDebugEnabled()) log.debug("Container logging ended for proxy " + proxy.getId());
 		});
 	}
 
+	public void detach(Proxy proxy) {
+		if (!isLoggingEnabled()) return;
+
+		OutputStream[] streams = (OutputStream[]) proxy.getContainers().get(0).getParameters().get(PARAM_STREAMS);
+		if (streams == null || streams.length < 2) {
+			log.warn("Cannot detach container logging: streams not found");
+			return;
+		}
+		for (int i = 0; i < streams.length; i++) {
+			try {
+				streams[i].flush();
+				streams[i].close();
+			} catch (IOException e) {
+				log.error("Failed to close container logging streams", e);
+			}
+		}
+	}
+
 	public String[] getLogs(Proxy proxy) {
 		if (!isLoggingEnabled()) return null;
 

src/main/java/eu/openanalytics/containerproxy/service/ProxyService.java

@@ -251,6 +251,7 @@ public void stopProxy(Proxy proxy, boolean async, boolean ignoreAccessControl) {
 		Runnable releaser = () -> {
 			try {
 				backend.stopProxy(proxy);
+				logService.detach(proxy);
 				log.info(String.format("Proxy released [user: %s] [spec: %s] [id: %s]", proxy.getUserId(), proxy.getSpec().getId(), proxy.getId()));
 				eventService.post(EventType.ProxyStop.toString(), proxy.getUserId(), proxy.getSpec().getId());
 			} catch (Exception e){