302: Add custom reader for docker logs

src/main/java/com/amihaiemil/docker/ReadLogString.java

@@ -0,0 +1,228 @@
+/**
+ * Copyright (c) 2018-2019, Mihai Emil Andronache
+ * All rights reserved.
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * 1)Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ * 2)Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ * 3)Neither the name of docker-java-api nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+package com.amihaiemil.docker;
+
+import org.apache.http.HttpEntity;
+import org.apache.http.HttpResponse;
+import org.apache.http.client.ResponseHandler;
+import org.apache.http.entity.ContentType;
+import org.apache.http.protocol.HTTP;
+import org.apache.http.util.Args;
+import org.apache.http.util.CharArrayBuffer;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.Reader;
+import java.nio.charset.Charset;
+
+/**
+ * Handler that returns the response content as a String.
+ * @author Morozov Evgeniy (lumimul@gmail.com)
+ * @version $Id$
+ * @since 0.0.2
+ */
+final class ReadLogString implements ResponseHandler<String> {
+
+    /**
+     * Handlers to be executed before actually reading the array.
+     */
+    private final ResponseHandler<HttpResponse> other;
+
+    /**
+     * Ctor.
+     * @param other Handlers to be executed before actually reading the array.
+     */
+    ReadLogString(final ResponseHandler<HttpResponse> other) {
+        this.other = other;
+    }
+
+    @Override
+    public String handleResponse(final HttpResponse httpResponse)
+            throws IOException {
+        final HttpResponse resp = this.other.handleResponse(httpResponse);
+        return this.toString(resp.getEntity());
+    }
+
+    /**
+     * Docker logs contains header
+     * [8]byte{STREAM_TYPE, 0, 0, 0, SIZE1, SIZE2, SIZE3, SIZE4}
+     * STREAM_TYPE
+     * 0: stdin (is written on stdout)
+     * 1: stdout
+     * 2: stderr
+     *
+     * SIZE1, SIZE2, SIZE3, SIZE4 are the four bytes of the uint32 size
+     * encoded as big endian.
+     *
+     * This method do:
+     *
+     * 1) Read 8 bytes.
+     * 2) Choose stdout or stderr depending on the first byte.
+     * 3) Extract the frame size from the last four bytes.
+     * 4) Read the extracted size and output it on the correct output.
+     * 5) Goto 1.
+     *
+     * @param entity HttpEntity for read message.
+     * @return Logs from container in String.
+     * @throws IOException if the entity cannot be read
+     */
+    private String toString(final HttpEntity entity) throws IOException {
+        final InputStream instream = entity.getContent();
+        final CharArrayBuffer buffer = new CharArrayBuffer(
+                this.getCapacity(entity)
+        );
+        if (instream != null) {
+            try {
+                final Reader reader = new InputStreamReader(
+                        instream,
+                        this.getCharset(ContentType.get(entity))
+                );
+                this.read(buffer, reader);
+            } finally {
+                instream.close();
+            }
+        }
+        return buffer.toString();
+    }
+
+    /**
+     * Docker logs contains header
+     * [8]byte{STREAM_TYPE, 0, 0, 0, SIZE1, SIZE2, SIZE3, SIZE4}
+     * STREAM_TYPE
+     * 0: stdin (is written on stdout)
+     * 1: stdout
+     * 2: stderr
+     *
+     * SIZE1, SIZE2, SIZE3, SIZE4 are the four bytes of the uint32 size
+     * encoded as big endian.
+     *
+     * 1) Read 8 bytes from reader.
+     * 2) Choose not stdin(0) depending on the first byte.
+     * 3) Extract the frame size from the last four bytes.
+     * 4) Read the extracted size from reader and save it in buffer in circle.
+     * 5) Goto 1.
+     *
+     * @param buffer Buffer for save message.
+     * @param reader Reader for read message.
+     * @throws IOException if the entity cannot be read
+     */
+    private void read(final CharArrayBuffer buffer,
+                      final Reader reader) throws IOException {
+        char[] controlChars = new char[8];
+        int len;
+        while (reader.read(controlChars) != -1) {
+            if (controlChars[0] != 0) {
+                long byteInLine = this.getUInt(controlChars);
+                char[] stdout;
+                if (byteInLine > 1024) {
+                    stdout = new char[1024];
+                } else {
+                    stdout = new char[(int) byteInLine];
+                }
+                while (byteInLine > 0) {
+                    len = reader.read(stdout);
+                    byteInLine -= len;
+                    if (len != -1) {
+                        buffer.append(stdout, 0, len);
+                    }
+                }
+            }
+        }
+    }
+
+    /**
+     * Check that content length less then Integer.MAX_VALUE.
+     * Try to get content length from entity
+     * If length less then zero return 4096
+     *
+     * @param entity HttpEntity for get capacity.
+     * @return Capacity.
+     */
+    private int getCapacity(final HttpEntity entity) {
+        Args.check(entity.getContentLength() <= Integer.MAX_VALUE,
+                "HTTP entity too large to be buffered in memory");
+        int capacity = (int) entity.getContentLength();
+        if (capacity < 0) {
+            capacity = 4096;
+        }
+        return capacity;
+    }
+
+    /**
+     * Try to get charset from content type.
+     * If charset not set, try get default charset by mime type
+     * If not set return ISO-8859-1
+     *
+     * @param contentType Content type.
+     * @return Charset.
+     */
+    private Charset getCharset(final ContentType contentType) {
+        Charset charset = null;
+        if (contentType != null) {
+            charset = contentType.getCharset();
+            if (charset == null) {
+                ContentType defaultContentType =
+                        ContentType.getByMimeType(contentType.getMimeType());
+                if (defaultContentType != null) {
+                    charset = defaultContentType.getCharset();
+                } else {
+                    charset = null;
+                }
+            }
+        }
+
+        if (charset == null) {
+            charset = HTTP.DEF_CONTENT_CHARSET;
+        }
+        return charset;
+    }
+
+    /**
+     * Convert byte to long.
+     *
+     * @param byteForConvert Byte for convert.
+     * @return Long Converted byte.
+     */
+    private long byteAsULong(final char byteForConvert) {
+        return ((long) byteForConvert) & 0x00000000000000FFL;
+    }
+
+    /**
+     * Convert byte from control byte to uint32.
+     *
+     * @param bytes Array of byte.
+     * @return Long uint32.
+     */
+    private long getUInt(final char[] bytes) {
+        return this.byteAsULong(bytes[7])
+                | (this.byteAsULong(bytes[6]) << 8)
+                | (this.byteAsULong(bytes[5]) << 16)
+                | (this.byteAsULong(bytes[4]) << 24);
+    }
+
+
+}

src/main/java/com/amihaiemil/docker/RtLogs.java

@@ -110,7 +110,7 @@ public String fetch() throws IOException, UnexpectedResponseException {
         try {
             return this.client.execute(
                 fetch,
-                new ReadString(
+                new ReadLogString(
                     new MatchStatus(
                         fetch.getURI(),
                         HttpStatus.SC_OK

src/test/java/com/amihaiemil/docker/RtLogsITCase.java

@@ -56,8 +56,8 @@ public void fetchesLogs() throws Exception {
         ).images().pull("hello-world", "latest").run();
         final String logs = container.logs().fetch();
         MatcherAssert.assertThat(
-            logs.trim(),
-            new StringStartsWith("Hello from Docker!")
+            logs,
+            new StringStartsWith("\nHello from Docker!")
         );
     }
 

src/test/java/com/amihaiemil/docker/RtLogsTestCase.java

@@ -99,7 +99,7 @@ public void followsLogs() throws Exception {
             );
         }
     }
-    
+
     /**
      * RtLogs can fetch the Container's logs (return them as a String).
      * @throws Exception If something goes wrong.
@@ -109,12 +109,8 @@ public void fetchesLogs() throws Exception {
         final Logs logs = new RtLogs(
             Mockito.mock(Container.class),
             new AssertRequest(
-                new Response(
-                    HttpStatus.SC_OK,
-                    Json.createObjectBuilder()
-                        .add("logs", "...fetched logs...")
-                        .build().toString()
-                ),
+                new Response(HttpStatus.SC_OK,
+                    this.prepareMessage("...fetched logs...")),
                 new Condition(
                     "Method should be a GET",
                     req -> req.getRequestLine().getMethod().equals("GET")
@@ -130,10 +126,37 @@ public void fetchesLogs() throws Exception {
         );
         MatcherAssert.assertThat(
             logs.fetch(),
-            Matchers.equalTo("{\"logs\":\"...fetched logs...\"}")
+            Matchers.equalTo("...fetched logs...")
         );
     }
-
+
+    /**
+     * Docker logs contains header -
+     * header := [8]byte{STREAM_TYPE, 0, 0, 0, SIZE1, SIZE2, SIZE3, SIZE4}
+     * STREAM_TYPE
+     * 0: stdin (is written on stdout)
+     * 1: stdout
+     * 2: stderr
+     *
+     * SIZE1, SIZE2, SIZE3, SIZE4 are the four bytes of the uint32 size
+     * encoded as big endian.
+     *
+     * @param message Message from container
+     * @return String with header.
+     */
+    private String prepareMessage(final String message) {
+        char[] chars = new char[8];
+        chars[0] = 1;
+        chars[1] = 0;
+        chars[2] = 0;
+        chars[3] = 0;
+        chars[4] = 0;
+        chars[5] = 0;
+        chars[6] = 0;
+        chars[7] = (char) message.length();
+        return new String(chars) + message;
+    }
+
     /**
      * RtLogs.toString() fetches the logs as String.
      */
@@ -144,9 +167,7 @@ public void toStringFetch() {
             new AssertRequest(
                 new Response(
                     HttpStatus.SC_OK,
-                    Json.createObjectBuilder()
-                        .add("logs", "toString logs")
-                        .build().toString()
+                    this.prepareMessage("toString logs")
                 ),
                 new Condition(
                     "Method should be a GET",
@@ -163,7 +184,7 @@ public void toStringFetch() {
         );
         MatcherAssert.assertThat(
             logs.toString(),
-            Matchers.equalTo("{\"logs\":\"toString logs\"}")
+            Matchers.equalTo("toString logs")
         );
     }
 
@@ -178,9 +199,7 @@ public void logStdout() throws Exception {
             new AssertRequest(
                 new Response(
                     HttpStatus.SC_OK,
-                    Json.createObjectBuilder()
-                        .add("logs", "stdout logs")
-                        .build().toString()
+                    this.prepareMessage("stdout logs")
                 ),
                 new Condition(
                     "Method should be a GET",
@@ -197,7 +216,7 @@ public void logStdout() throws Exception {
         );
         MatcherAssert.assertThat(
             logs.stdout().fetch(),
-            Matchers.equalTo("{\"logs\":\"stdout logs\"}")
+            Matchers.equalTo("stdout logs")
         );
     }
 
@@ -212,9 +231,7 @@ public void logStderr() throws Exception {
             new AssertRequest(
                 new Response(
                     HttpStatus.SC_OK,
-                    Json.createObjectBuilder()
-                        .add("logs", "stderr logs")
-                        .build().toString()
+                    this.prepareMessage("stderr logs")
                 ),
                 new Condition(
                     "Method should be a GET",
@@ -231,7 +248,7 @@ public void logStderr() throws Exception {
         );
         MatcherAssert.assertThat(
             logs.stderr().fetch(),
-            Matchers.equalTo("{\"logs\":\"stderr logs\"}")
+            Matchers.equalTo("stderr logs")
         );
     }