web/impl-osgi/src/main/java/org/opendaylight/aaa/web/osgi/WhiteboardWebServer.java

   1 /*
   2  * Copyright (c) 2022 PANTHEON.tech, s.r.o. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8 package org.opendaylight.aaa.web.osgi;
   9
  10 import com.google.common.collect.ImmutableList;
  11 import com.google.common.collect.ImmutableMap;
  12 import java.util.Arrays;
  13 import java.util.Collection;
  14 import java.util.List;
  15 import java.util.Map;
  16 import java.util.stream.Collectors;
  17 import javax.servlet.Filter;
  18 import javax.servlet.Servlet;
  19 import javax.servlet.ServletContextListener;
  20 import javax.servlet.ServletException;
  21 import org.opendaylight.aaa.web.FilterDetails;
  22 import org.opendaylight.aaa.web.ResourceDetails;
  23 import org.opendaylight.aaa.web.ServletDetails;
  24 import org.opendaylight.aaa.web.WebContext;
  25 import org.opendaylight.aaa.web.WebServer;
  26 import org.opendaylight.yangtools.concepts.AbstractRegistration;
  27 import org.opendaylight.yangtools.concepts.Registration;
  28 import org.osgi.framework.Bundle;
  29 import org.osgi.framework.FrameworkUtil;
  30 import org.osgi.framework.ServiceReference;
  31 import org.osgi.framework.ServiceRegistration;
  32 import org.osgi.service.component.ComponentContext;
  33 import org.osgi.service.component.annotations.Activate;
  34 import org.osgi.service.component.annotations.Component;
  35 import org.osgi.service.component.annotations.Deactivate;
  36 import org.osgi.service.component.annotations.Reference;
  37 import org.osgi.service.component.annotations.ServiceScope;
  38 import org.osgi.service.http.context.ServletContextHelper;
  39 import org.osgi.service.http.runtime.HttpServiceRuntime;
  40 import org.osgi.service.http.runtime.HttpServiceRuntimeConstants;
  41 import org.osgi.service.http.whiteboard.HttpWhiteboardConstants;
  42 import org.osgi.service.http.whiteboard.annotations.RequireHttpWhiteboard;
  43 import org.slf4j.Logger;
  44 import org.slf4j.LoggerFactory;
  45
  46 /**
  47  * {@link WebServer} implementation based on
  48  * <a href="https://docs.osgi.org/specification/osgi.cmpn/7.0.0/service.http.whiteboard.html">OSGi HTTP Whiteboard</a>.
  49  */
  50 @RequireHttpWhiteboard
  51 @Component(scope = ServiceScope.BUNDLE)
  52 public final class WhiteboardWebServer implements WebServer {
  53     private static final Logger LOG = LoggerFactory.getLogger(WhiteboardWebServer.class);
  54
  55     private final Bundle bundle;
  56     @Reference
  57     private volatile ServiceReference<HttpServiceRuntime> serviceRuntime;
  58
  59     /**
  60      * Construct a {@link WhiteboardWebServer} to a {@link ComponentContext}.
  61      *
  62      * @param componentContext A {@link ComponentContext}
  63      */
  64     @Activate
  65     public WhiteboardWebServer(final ComponentContext componentContext) {
  66         bundle = componentContext.getUsingBundle();
  67         LOG.debug("Activated WebServer for bundle {}", bundle);
  68     }
  69
  70     @Deactivate
  71     void deactivate() {
  72         LOG.debug("Deactivated WebServer for bundle {}", bundle);
  73     }
  74
  75     @Override
  76     public String getBaseURL() {
  77         final var endpoint = serviceRuntime.getProperty(HttpServiceRuntimeConstants.HTTP_SERVICE_ENDPOINT);
  78         if (endpoint instanceof String str) {
  79             return str;
  80         } else if (endpoint instanceof String[] endpoints) {
  81             return getBaseURL(Arrays.asList(endpoints));
  82         } else if (endpoint instanceof Collection) {
  83             // Safe as per OSGi Compendium R7 section 140.15.3.1
  84             @SuppressWarnings("unchecked")
  85             final var cast = (Collection<String>) endpoint;
  86             return getBaseURL(cast);
  87         } else {
  88             throw new IllegalStateException("Unhandled endpoint " + endpoint);
  89         }
  90     }
  91
  92     private static String getBaseURL(final Collection<String> endpoints) {
  93         for (var endpoint : endpoints) {
  94             if (endpoint.startsWith("http://") || endpoint.startsWith("https://")) {
  95                 return endpoint;
  96             }
  97         }
  98         throw new IllegalStateException("Cannot select base URL from " + endpoints);
  99     }
 100
 101     @Override
 102     public Registration registerWebContext(final WebContext webContext) throws ServletException {
 103         final var bundleContext = bundle.getBundleContext();
 104         final var builder = ImmutableList.<ServiceRegistration<?>>builder();
 105
 106         // The order in which we set things up here matters...
 107
 108         // 1. ServletContextHelper, to which all others are bound to
 109         final var contextPath = absolutePath(webContext.contextPath());
 110         // TODO: can we create a better name?
 111         final var contextName = contextPath + ".id";
 112
 113         final var contextProps = contextProperties(contextName, contextPath, webContext.contextParams());
 114         LOG.debug("Registering context {} with properties {}", contextName, contextProps);
 115         builder.add(bundleContext.registerService(ServletContextHelper.class,
 116             new WhiteboardServletContextHelper(bundle), FrameworkUtil.asDictionary(contextProps)));
 117
 118         // 2. Listeners - because they could set up things that filters and servlets need
 119         final var contextSelect = "(" + HttpWhiteboardConstants.HTTP_WHITEBOARD_CONTEXT_NAME + "=" + contextName + ")";
 120         for (var listener : webContext.listeners()) {
 121             final var props = Map.of(
 122                 HttpWhiteboardConstants.HTTP_WHITEBOARD_CONTEXT_SELECT, contextSelect,
 123                 HttpWhiteboardConstants.HTTP_WHITEBOARD_LISTENER, "true");
 124             LOG.debug("Registering listener {} with properties {}", listener, props);
 125             builder.add(bundleContext.registerService(ServletContextListener.class, listener,
 126                 FrameworkUtil.asDictionary(props)));
 127         }
 128
 129         // 3. Filters - because subsequent servlets should already be covered by the filters
 130         for (var filter : webContext.filters()) {
 131             final var props = filterProperties(contextSelect, filter);
 132             LOG.debug("Registering filter {} with properties {}", filter, props);
 133             builder.add(bundleContext.registerService(Filter.class, filter.filter(),
 134                 FrameworkUtil.asDictionary(props)));
 135         }
 136
 137         // 4. Servlets - 'bout time for 'em by now, don't you think? ;)
 138         for (var servlet : webContext.servlets()) {
 139             final var props = servletProperties(contextSelect, servlet);
 140             LOG.debug("Registering servlet {} with properties {}", servlet, props);
 141             builder.add(bundleContext.registerService(Servlet.class, servlet.servlet(),
 142                 FrameworkUtil.asDictionary(props)));
 143         }
 144
 145         // 5. Resources
 146         for (var resource : webContext.resources()) {
 147             final var props = resourceProperties(contextSelect, resource);
 148             LOG.debug("Registering resource {} with properties {}", resource, props);
 149             builder.add(bundleContext.registerService(Object.class, WhiteboardResource.INSTANCE,
 150                 FrameworkUtil.asDictionary(props)));
 151         }
 152
 153         final var services = builder.build();
 154         LOG.info("Bundle {} registered context path {} with {} service(s)", bundle, contextPath, services.size());
 155         return new AbstractRegistration() {
 156             @Override
 157             protected void removeRegistration() {
 158                 // The order does not have to be reversed: we unregister ServletContextHelper first, hence everybody
 159                 // becomes unbound
 160                 services.forEach(ServiceRegistration::unregister);
 161             }
 162         };
 163     }
 164
 165     private static Map<String, Object> contextProperties(final String contextName, final String contextPath,
 166             final Map<String, String> params) {
 167         final var builder = ImmutableMap.<String, Object>builder()
 168             .put(HttpWhiteboardConstants.HTTP_WHITEBOARD_CONTEXT_NAME, contextName)
 169             .put(HttpWhiteboardConstants.HTTP_WHITEBOARD_CONTEXT_PATH, contextPath);
 170
 171         for (var e : params.entrySet()) {
 172             builder.put(HttpWhiteboardConstants.HTTP_WHITEBOARD_CONTEXT_INIT_PARAM_PREFIX + e.getKey(), e.getValue());
 173         }
 174
 175         return builder.build();
 176     }
 177
 178     private static Map<String, Object> filterProperties(final String contextSelect, final FilterDetails filter) {
 179         final var builder = ImmutableMap.<String, Object>builder()
 180             .put(HttpWhiteboardConstants.HTTP_WHITEBOARD_CONTEXT_SELECT, contextSelect)
 181             .put(HttpWhiteboardConstants.HTTP_WHITEBOARD_FILTER_ASYNC_SUPPORTED, filter.getAsyncSupported())
 182             .put(HttpWhiteboardConstants.HTTP_WHITEBOARD_FILTER_NAME, filter.name())
 183             .put(HttpWhiteboardConstants.HTTP_WHITEBOARD_FILTER_PATTERN, absolutePatterns(filter.urlPatterns()));
 184
 185         for (var e : filter.initParams().entrySet()) {
 186             builder.put(HttpWhiteboardConstants.HTTP_WHITEBOARD_FILTER_INIT_PARAM_PREFIX + e.getKey(), e.getValue());
 187         }
 188
 189         return builder.build();
 190     }
 191
 192     private static Map<String, Object> resourceProperties(final String contextSelect, final ResourceDetails resource) {
 193         final var path = absolutePath(resource.name());
 194         return Map.of(
 195             HttpWhiteboardConstants.HTTP_WHITEBOARD_CONTEXT_SELECT, contextSelect,
 196             HttpWhiteboardConstants.HTTP_WHITEBOARD_RESOURCE_PATTERN, path,
 197             HttpWhiteboardConstants.HTTP_WHITEBOARD_RESOURCE_PREFIX, path);
 198     }
 199
 200     private static Map<String, Object> servletProperties(final String contextSelect, final ServletDetails servlet) {
 201         final var builder = ImmutableMap.<String, Object>builder()
 202             .put(HttpWhiteboardConstants.HTTP_WHITEBOARD_CONTEXT_SELECT, contextSelect)
 203             .put(HttpWhiteboardConstants.HTTP_WHITEBOARD_SERVLET_ASYNC_SUPPORTED, servlet.getAsyncSupported())
 204             .put(HttpWhiteboardConstants.HTTP_WHITEBOARD_SERVLET_NAME, servlet.name())
 205             .put(HttpWhiteboardConstants.HTTP_WHITEBOARD_SERVLET_PATTERN, absolutePatterns(servlet.urlPatterns()));
 206
 207         for (var e : servlet.initParams().entrySet()) {
 208             builder.put(HttpWhiteboardConstants.HTTP_WHITEBOARD_SERVLET_INIT_PARAM_PREFIX + e.getKey(), e.getValue());
 209         }
 210
 211         return builder.build();
 212     }
 213
 214     private static String absolutePath(final String path) {
 215         return path.startsWith("/") ? path : "/" + path;
 216     }
 217
 218     private static List<String> absolutePatterns(final List<String> urlPatterns) {
 219         return urlPatterns.stream()
 220             // Reject duplicates
 221             .distinct()
 222             // Ease of debugging
 223             .sorted()
 224             .collect(Collectors.toUnmodifiableList());
 225     }
 226 }