BackwardsCompatibilityInterceptor.java

/**
 * Copyright (C) 2015 Red Hat, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *         http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package io.fabric8.kubernetes.client.utils;

import io.fabric8.kubernetes.api.model.HasMetadata;
import io.fabric8.kubernetes.client.dsl.base.OperationSupport;
import okhttp3.Interceptor;
import okhttp3.Request;
import okhttp3.RequestBody;
import okhttp3.Response;
import okio.Buffer;

import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import java.util.Objects;
import java.util.regex.Pattern;
import java.util.regex.Matcher;

public class BackwardsCompatibilityInterceptor implements Interceptor {

  private static final int API_GROUP = 1;
  private static final int API_VERSION = 2;
  private static final int PATH = 3;

  private static final String PATCH = "patch";
  private static final String NAME_REGEX = "[a-z0-9\\-\\.]+";
  private static final Pattern URL_PATTERN = Pattern.compile("[^ ]+/apis/(" + NAME_REGEX + ")/(" + NAME_REGEX + ")/(" + NAME_REGEX + ")[^ ]*");
  private static final Pattern NAMESPACED_URL_PATTERN = Pattern.compile("[^ ]+/apis/(" + NAME_REGEX + ")/(" + NAME_REGEX + ")/namespaces/" + NAME_REGEX + "/(" + NAME_REGEX + ")[^ ]*");
  private static final Map<ResourceKey, ResourceKey> notFoundTransformations = new HashMap<>();
  private static final Map<ResourceKey, ResourceKey> badRequestTransformations = new HashMap<>();
  private static final Map<String, ResourceKey> openshiftOAPITransformations = new HashMap<>();

  private static final Map<Integer, Map<ResourceKey, ResourceKey>> responseCodeToTransformations = new HashMap<>();

  private static class ResourceKey {
    private final String kind;
    private final String path;
    private final String group;
    private final String version;

    public ResourceKey(String kind, String path, String group, String version) {
      this.kind = kind;
      this.path = path;
      this.group = group;
      this.version = version;
    }

    public String getKind() {
      return kind;
    }

    public String getPath() {
      return path;
    }

    public String getGroup() {
      return group;
    }

    public String getVersion() {
      return version;
    }

    @Override
    public boolean equals(Object o) {
      if (this == o) return true;
      if (o == null || getClass() != o.getClass()) return false;
      ResourceKey key = (ResourceKey) o;
      return Objects.equals(path, key.path) &&
        Objects.equals(group, key.group) &&
        Objects.equals(version, key.version);
    }

    @Override
    public int hashCode() {

      return Objects.hash(path, group, version);
    }
  }

  static {
    notFoundTransformations.put(new ResourceKey("Deployment", "deployments", "apps", "v1"), new ResourceKey("Deployment", "deployments", "extensions", "v1beta1"));
    notFoundTransformations.put(new ResourceKey("StatefulSet", "statefulsets", "apps", "v1"), new ResourceKey("StatefulSet", "statefulsets", "apps", "v1beta1"));
    notFoundTransformations.put(new ResourceKey("DaemonSets", "daemonsets", "apps", "v1"), new ResourceKey("DaemonSet", "daemonsets", "extensions", "v1beta1"));
    notFoundTransformations.put(new ResourceKey("ReplicaSets", "replicasets", "apps", "v1"), new ResourceKey("ReplicaSet", "replicasets", "extensions", "v1beta1"));
    notFoundTransformations
      .put(new ResourceKey("NetworkPolicy", "networkpolicies", "networking.k8s.io", "v1"), new ResourceKey("NetworkPolicy", "networkpolicies", "extensions", "v1beta1"));
    notFoundTransformations
      .put(new ResourceKey("StorageClass", "storageclasses", "storage.k8s.io", "v1"), new ResourceKey("StorageClass", "storageclasses", "extensions", "v1beta1"));
    notFoundTransformations
      .put(new ResourceKey("Job", "jobs", "batch", "v1"), new ResourceKey("Job", "jobs", "extensions", "v1beta1"));
    notFoundTransformations.put(new ResourceKey("RoleBinding", "rolebindings", "rbac.authorization.k8s.io", "v1"), new ResourceKey("RoleBinding", "rolebindings", "rbac.authorization.k8s.io", "v1beta1"));
    notFoundTransformations.put(new ResourceKey("Role", "roles", "rbac.authorization.k8s.io", "v1"), new ResourceKey("Role", "roles", "rbac.authorization.k8s.io", "v1beta1"));
    notFoundTransformations.put(new ResourceKey("ClusterRoleBinding", "clusterrolebindings", "rbac.authorization.k8s.io", "v1"), new ResourceKey("ClusterRoleBinding", "clusterrolebindings", "rbac.authorization.k8s.io", "v1beta1"));
    notFoundTransformations.put(new ResourceKey("ClusterRole", "clusterroles", "rbac.authorization.k8s.io", "v1"), new ResourceKey("ClusterRole", "clusterroles", "rbac.authorization.k8s.io", "v1beta1"));
    notFoundTransformations.put(new ResourceKey("CronJob", "cronjobs", "batch", "v1beta1"), new ResourceKey("CronJob", "cronjob", "batch", "v2alpha1"));
    notFoundTransformations.put(new ResourceKey("Template", "template", "", "v1"), new ResourceKey("Template", "template", "template.openshift.io", "v1"));

    badRequestTransformations.put(new ResourceKey("Deployment", "deployments", "apps", "v1beta1"), new ResourceKey("Deployment", "deployments", "extensions", "v1beta1"));

    responseCodeToTransformations.put(400, badRequestTransformations);
    responseCodeToTransformations.put(404, notFoundTransformations);

    /**
     * OpenShift versions prior to 3.10 use the /oapi endpoint for Openshift specific resources.
     * However, since 3.10 /apis/{group} is being used. This has been removed completely in 4.x
     * versions of OpenShift. Hence, this code is to handle those cases.
     */
    openshiftOAPITransformations.put("routes", new ResourceKey("Route", "routes", "route.openshift.io", "v1"));
    openshiftOAPITransformations.put("templates", new ResourceKey("Template", "templates", "template.openshift.io", "v1"));
    openshiftOAPITransformations.put("buildconfigs", new ResourceKey("BuildConfig", "buildconfigs", "build.openshift.io", "v1"));
    openshiftOAPITransformations.put("deploymentconfigs", new ResourceKey("DeploymentConfig", "deploymentconfigs", "apps.openshift.io", "v1"));
    openshiftOAPITransformations.put("imagestreams", new ResourceKey("ImageStream", "imagestreams", "image.openshift.io", "v1"));
    openshiftOAPITransformations.put("imagestreamtags", new ResourceKey("ImageStream", "imagestreamtags", "image.openshift.io", "v1"));
    openshiftOAPITransformations.put("securitycontextconstraints", new ResourceKey("SecurityContextConstraints", "securitycontextconstraints", "security.openshift.io", "v1"));
  }

  public Response intercept(Chain chain) throws IOException {
    Request request = chain.request();
    Response response = chain.proceed(request);
    if (isDeprecatedOpenshiftOapiRequest(request)) {
      return handleOpenshiftOapiRequests(request, response, chain);
    } else if (!response.isSuccessful() && responseCodeToTransformations.keySet().contains(response.code())) {
      String url = request.url().toString();
      Matcher matcher = getMatcher(url);
      ResourceKey key = getKey(matcher);
      ResourceKey target = responseCodeToTransformations.get(response.code()).get(key);
      if (target != null) {
        response.close(); // At this point, we know we won't reuse or return the response; so close it to avoid a connection leak.
        String newUrl = new StringBuilder(url)
          .replace(matcher.start(API_VERSION), matcher.end(API_VERSION), target.version) // Order matters: We need to substitute right to left, so that former substitution don't affect the indexes of later.
          .replace(matcher.start(API_GROUP), matcher.end(API_GROUP), target.group)
          .toString();

        return handleNewRequestAndProceed(request, newUrl, target, chain);
      }
    }
    return response;
  }

  private static Matcher getMatcher(String url) {
    Matcher m = NAMESPACED_URL_PATTERN.matcher(url);
    if (m.matches()) {
      return m;
    }

    m = URL_PATTERN.matcher(url);
    if (m.matches()) {
      return m;
    }
    return null;
  }

  private static ResourceKey getKey(Matcher m) {
    return m != null ? new ResourceKey(null, m.group(PATH), m.group(API_GROUP), m.group(API_VERSION)) : null;
  }

  private static Response handleOpenshiftOapiRequests(Request request, Response response, Chain chain) throws IOException{
    if (!response.isSuccessful()) {
      String requestUrl = request.url().toString();
      // handle case when /oapi is not available
      String[] parts = requestUrl.split("/");
      String resourcePath = parts[parts.length - 1];
      ResourceKey target = openshiftOAPITransformations.get(resourcePath);
      if (target != null) {
        requestUrl = requestUrl.replace("/oapi", "/apis/" + target.getGroup());
        return handleNewRequestAndProceed(request, requestUrl, target, chain);
      }
    }
    return response;
  }

  private static Response handleNewRequestAndProceed(Request request, String newUrl, ResourceKey target, Chain chain) throws IOException {
    Request.Builder newRequest = request.newBuilder()
      .url(newUrl);

    if (request.body() != null && !request.method().equalsIgnoreCase(PATCH)) {
      try (Buffer buffer = new Buffer()) {
        request.body().writeTo(buffer);

        Object object = Serialization.unmarshal(buffer.inputStream());
        if (object instanceof HasMetadata) {
          HasMetadata h = (HasMetadata) object;
          if (target != null) {
            h.setApiVersion(target.group + "/" + target.version);
          }
          newRequest = newRequest.method(request.method(), RequestBody.create(OperationSupport.JSON, Serialization.asJson(h)));
        }
      }
    }

    return chain.proceed(newRequest.build());
  }

  private static boolean isDeprecatedOpenshiftOapiRequest(Request request) {
    if (request != null && request.url() != null) {
      return request.url().toString().contains("oapi");
    }
    return false;
  }
}