feat (jkube-kit/common) : Add HTTP utility methods to Fabric8HttpUtil

Add various methods required for performing HTTP requests to
Fabric8HttpUtil. Use Fabric8 K8s Client's HttpResponse abstractions for HTTP
requests.

Signed-off-by: Rohan Kumar <rohaan@redhat.com>

jkube-kit/common/src/main/java/org/eclipse/jkube/kit/common/util/Fabric8HttpUtil.java

@@ -0,0 +1,71 @@
+/**
+ * Copyright (c) 2019 Red Hat, Inc.
+ * This program and the accompanying materials are made
+ * available under the terms of the Eclipse Public License 2.0
+ * which is available at:
+ *
+ *     https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *   Red Hat, Inc. - initial API and implementation
+ */
+package org.eclipse.jkube.kit.common.util;
+
+import io.fabric8.kubernetes.client.http.HttpResponse;
+
+import java.io.UnsupportedEncodingException;
+import java.net.URLEncoder;
+import java.nio.charset.StandardCharsets;
+import java.util.HashMap;
+import java.util.Map;
+
+import static org.apache.commons.lang3.StringUtils.strip;
+
+public class Fabric8HttpUtil {
+  private static final String WWW_AUTHENTICATE = "WWW-Authenticate";
+
+  private Fabric8HttpUtil() { }
+
+  /**
+   * Parse WWW-Authenticate Header as map
+   *
+   * @param response Http Response of a particular request
+   * @return map containing various components of header as key value pairs
+   */
+  public static Map<String, String> extractAuthenticationChallengeIntoMap(HttpResponse<byte[]> response) {
+    String wwwAuthenticateHeader = response.header(WWW_AUTHENTICATE);
+    String[] wwwAuthenticateHeaders = wwwAuthenticateHeader.split(",");
+    Map<String, String> result = new HashMap<>();
+    for (String challenge : wwwAuthenticateHeaders) {
+      if (challenge.contains("=")) {
+        String[] challengeParts = challenge.split("=");
+        if (challengeParts.length == 2) {
+          result.put(challengeParts[0], strip(challengeParts[1], "\""));
+        }
+      }
+    }
+    return result;
+  }
+
+
+  /**
+   * Create Form Data String from map
+   *
+   * @param formData map containing key value pairs for form data
+   * @return URL encoded value of form data
+   */
+  public static String toFormData(Map<String, String> formData) throws UnsupportedEncodingException {
+    StringBuilder result = new StringBuilder();
+    for (Map.Entry<String, String> e : formData.entrySet()) {
+      if (result.length() > 0) {
+        result.append("&");
+      }
+      result.append(URLEncoder.encode(e.getKey(), StandardCharsets.UTF_8.name()));
+      result.append("=");
+      result.append(URLEncoder.encode(e.getValue(), StandardCharsets.UTF_8.name()));
+    }
+    return result.toString();
+  }
+}

jkube-kit/common/src/test/java/org/eclipse/jkube/kit/common/util/Fabric8HttpUtilTest.java

@@ -0,0 +1,68 @@
+/**
+ * Copyright (c) 2019 Red Hat, Inc.
+ * This program and the accompanying materials are made
+ * available under the terms of the Eclipse Public License 2.0
+ * which is available at:
+ *
+ *     https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *   Red Hat, Inc. - initial API and implementation
+ */
+package org.eclipse.jkube.kit.common.util;
+
+import io.fabric8.kubernetes.client.http.HttpResponse;
+import org.junit.jupiter.api.Test;
+
+import java.io.UnsupportedEncodingException;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import static java.net.HttpURLConnection.HTTP_OK;
+import static org.assertj.core.api.Assertions.assertThat;
+
+class Fabric8HttpUtilTest {
+
+  @Test
+  void toFormData_whenDataProvidedAsMap_thenCreateFormDataPayload() throws UnsupportedEncodingException {
+    // Given
+    Map<String, String> formDataMap = new HashMap<>();
+    formDataMap.put("grant_type", "password");
+    formDataMap.put("refresh_token", "secret");
+    formDataMap.put("service", "auth.example.com");
+    formDataMap.put("scope", "repository=myuser/test-chart:pull");
+    formDataMap.put("client id", "Eclipse&JKube");
+    formDataMap.put("username", "?myuser");
+    formDataMap.put("password", "secret");
+
+    // When
+    String formDataPayload = Fabric8HttpUtil.toFormData(formDataMap);
+
+    // Then
+    assertThat(formDataPayload)
+        .isEqualTo("client+id=Eclipse%26JKube&refresh_token=secret&password=secret&grant_type=password&service=auth.example.com&scope=repository%3Dmyuser%2Ftest-chart%3Apull&username=%3Fmyuser");
+  }
+
+  @Test
+  void extractAuthenticationChallengeIntoMap_whenWwwHeaderProvided_thenParseDataIntoMap() {
+    // Given
+    String wwwAuthenticateValue = "Bearer realm=\"https://auth.example.com/token\",service=\"registry.example.com\",scope=\"repository:myuser/test-chart:pull\"";
+    Map<String, List<String>> responseHeaders = new HashMap<>();
+    responseHeaders.put("WWW-Authenticate", Collections.singletonList(wwwAuthenticateValue));
+    HttpResponse<byte[]> response = new TestFabric8HttpResponse(HTTP_OK, responseHeaders, null, null);
+
+    // When
+    Map<String, String> wwwAuthenticateAsMap = Fabric8HttpUtil.extractAuthenticationChallengeIntoMap(response);
+
+    // Then
+    assertThat(wwwAuthenticateAsMap)
+        .hasSize(3)
+        .containsEntry("Bearer realm", "https://auth.example.com/token")
+        .containsEntry("service", "registry.example.com")
+        .containsEntry("scope", "repository:myuser/test-chart:pull");
+  }
+}

jkube-kit/common/src/test/java/org/eclipse/jkube/kit/common/util/TestFabric8HttpResponse.java

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+/**
+ * Copyright (c) 2019 Red Hat, Inc.
+ * This program and the accompanying materials are made
+ * available under the terms of the Eclipse Public License 2.0
+ * which is available at:
+ *
+ *     https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *   Red Hat, Inc. - initial API and implementation
+ */
+package org.eclipse.jkube.kit.common.util;
+
+import io.fabric8.kubernetes.client.http.HttpRequest;
+import io.fabric8.kubernetes.client.http.HttpResponse;
+import org.apache.commons.lang3.StringUtils;
+
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+
+public class TestFabric8HttpResponse implements HttpResponse<byte[]> {
+  private final int code;
+  private final Map<String, List<String>> headers;
+  private final String body;
+  private final String message;
+
+  public TestFabric8HttpResponse(int code, Map<String, List<String>> headers, String body, String message) {
+    this.code = code;
+    this.headers = headers;
+    this.body = body;
+    this.message = message;
+  }
+
+  @Override
+  public int code() { return code; }
+
+  @Override
+  public byte[] body() {
+    if (StringUtils.isNotBlank(body)) {
+      return body.getBytes();
+    }
+    return null;
+  }
+
+  @Override
+  public HttpRequest request() { return null; }
+
+  @Override
+  public Optional<HttpResponse<?>> previousResponse() { return Optional.empty(); }
+
+  @Override
+  public List<String> headers(String s) { return headers.get(s); }
+
+  @Override
+  public Map<String, List<String>> headers() { return headers; }
+
+  @Override
+  public String message() { return message; }
+}