SOLR-16396: Migrate GET /config/requestHandler to JAX-RS

changelog/unreleased/SOLR-16396-config-requestHandler.yml

@@ -0,0 +1,10 @@
+title: >
+  Migrate GET /config/requestHandler to JAX-RS; V2 path and response key
+  are now plural requestHandlers (V1 unchanged)
+type: changed
+authors:
+  - name: Jalaz Kumar
+    nick: jaykay12
+links:
+  - name: SOLR-16396
+    url: https://issues.apache.org/jira/browse/SOLR-16396

solr/api/src/java/org/apache/solr/client/api/endpoint/ConfigApi.java

@@ -70,6 +70,27 @@ ConfigZnodeVersionResponse getZnodeVersion(
             @Parameter(description = "Expected request-params znode version")
             int expectedParamsVersion);
 
+    // TODO: RH names contain '/' (e.g. /select, /update/json), so they cannot be a @PathParam in
+    // the current design; Keeping filtering via @QueryParam for now.
+    @GET
+    @Path("/requestHandlers")
+    @StoreApiParameters
+    @Operation(
+        summary = "Fetch request handlers (including implicit handler)",
+        tags = {"config"})
+    ConfigInfoResponse getRequestHandler(
+        @QueryParam("componentName")
+            @Parameter(description = "Name of the specific request handler")
+            String component,
+        @QueryParam("expandParams")
+            @DefaultValue("false")
+            @Parameter(description = "Expand request handler useParams and effective parameters")
+            boolean expandParams,
+        @QueryParam("meta")
+            @DefaultValue("false")
+            @Parameter(description = "Include package metadata (_packageinfo_)")
+            boolean meta);
+
     // TODO: Keep this regex in sync with GetConfig.MIGRATED_CONFIG_COMPONENTS ("searchComponents"
     // and "queryResponseWriters" here are the external, pluralized names for the internal
     // "searchComponent"/"queryResponseWriter" sections; see GetConfig#toExternalComponentName)

solr/api/src/java/org/apache/solr/client/api/util/Constants.java

@@ -24,8 +24,18 @@ private Constants() {
 
   public static final String INDEX_TYPE_PATH_PARAMETER = "indexType";
   public static final String INDEX_NAME_PATH_PARAMETER = "indexName";
+
+  // "c" is accepted alongside "collections" because Solr internally forwards a v2 request to the
+  // node actually hosting a collection using the short "/c/{collection}/..." alias (see
+  // HttpSolrCall#sendRemoteProxy and V2HttpCall's "c"/"collections" handling); without it, any
+  // JAX-RS resource built on this prefix 404s with "Cannot find API for the path" whenever the
+  // request has to be proxied to another node.
   public static final String INDEX_PATH_PREFIX =
-      "/{" + INDEX_TYPE_PATH_PARAMETER + ":cores|collections}/{" + INDEX_NAME_PATH_PARAMETER + "}";
+      "/{"
+          + INDEX_TYPE_PATH_PARAMETER
+          + ":cores|collections|c}/{"
+          + INDEX_NAME_PATH_PARAMETER
+          + "}";
 
   public static final String CORE_NAME_PATH_PARAMETER = "coreName";
 

solr/core/src/java/org/apache/solr/handler/SolrConfigHandler.java

@@ -21,10 +21,7 @@
 import static org.apache.solr.core.ConfigOverlay.NOT_EDITABLE;
 import static org.apache.solr.core.ConfigOverlay.ZNODEVER;
 import static org.apache.solr.core.ConfigSetProperties.IMMUTABLE_CONFIGSET_ARG;
-import static org.apache.solr.core.PluginInfo.APPENDS;
 import static org.apache.solr.core.PluginInfo.DEFAULTS;
-import static org.apache.solr.core.PluginInfo.INVARIANTS;
-import static org.apache.solr.core.RequestParams.USEPARAM;
 import static org.apache.solr.core.SolrConfig.PluginOpts.REQUIRE_CLASS;
 import static org.apache.solr.core.SolrConfig.PluginOpts.REQUIRE_NAME;
 import static org.apache.solr.core.SolrConfig.PluginOpts.REQUIRE_NAME_IN_OVERLAY;
@@ -69,7 +66,6 @@
 import org.apache.solr.common.cloud.Replica;
 import org.apache.solr.common.cloud.Slice;
 import org.apache.solr.common.params.CommonParams;
-import org.apache.solr.common.params.MapSolrParams;
 import org.apache.solr.common.params.ModifiableSolrParams;
 import org.apache.solr.common.params.SolrParams;
 import org.apache.solr.common.util.CommandOperation;
@@ -97,7 +93,6 @@
 import org.apache.solr.security.AuthorizationContext;
 import org.apache.solr.security.PermissionNameProvider;
 import org.apache.solr.util.RTimer;
-import org.apache.solr.util.SolrPluginUtils;
 import org.apache.solr.util.plugin.SolrCoreAware;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -221,6 +216,15 @@ private void handleGET() {
                     .getZnodeVersion(
                         req.getParams().getInt(ConfigOverlay.NAME, -1),
                         req.getParams().getInt(RequestParams.NAME, -1)));
+          } else if (SolrRequestHandler.TYPE.equals(parts.get(1))) {
+            V2ApiUtils.squashIntoSolrResponseWithoutHeader(
+                resp,
+                new GetConfig(req)
+                    .getRequestHandler(
+                        parts.get(1),
+                        req.getParams().get("componentName"),
+                        req.getParams().getBool("expandParams", false),
+                        req.getParams().getBool("meta", false)));
           } else if (GetConfig.MIGRATED_CONFIG_COMPONENTS.contains(parts.get(1))) {
             String componentName = req.getParams().get("componentName");
             GetConfig getConfig = new GetConfig(req);
@@ -231,7 +235,8 @@ private void handleGET() {
                     : getConfig.getConfigComponentByName(
                         parts.get(1), componentName, req.getParams().getBool("meta", false)));
           } else {
-            Map<String, Object> m = getConfigDetails(parts.get(1), req);
+            Map<String, Object> m =
+                Utils.convertToMap(req.getCore().getSolrConfig(), new LinkedHashMap<>());
             Map<String, Object> val = new LinkedHashMap<>();
             val.put(parts.get(1), m.get(parts.get(1)));
             String componentName = req.getParams().get("componentName");
@@ -245,79 +250,6 @@ private void handleGET() {
       }
     }
 
-    private Map<String, Object> getConfigDetails(String componentType, SolrQueryRequest req) {
-      String componentName = componentType == null ? null : req.getParams().get("componentName");
-      boolean showParams = req.getParams().getBool("expandParams", false);
-      Map<String, Object> map =
-          Utils.convertToMap(this.req.getCore().getSolrConfig(), new LinkedHashMap<>());
-      if (componentType != null && !SolrRequestHandler.TYPE.equals(componentType)) return map;
-
-      @SuppressWarnings({"unchecked"})
-      Map<String, Object> reqHandlers =
-          (Map<String, Object>)
-              map.computeIfAbsent(SolrRequestHandler.TYPE, k -> new LinkedHashMap<>());
-      List<PluginInfo> plugins = this.req.getCore().getImplicitHandlers();
-      for (PluginInfo plugin : plugins) {
-        if (SolrRequestHandler.TYPE.equals(plugin.type)) {
-          if (!reqHandlers.containsKey(plugin.name)) {
-            reqHandlers.put(plugin.name, plugin);
-          }
-        }
-      }
-      if (!showParams) return map;
-      for (Map.Entry<String, Object> e : reqHandlers.entrySet()) {
-        if (componentName == null || e.getKey().equals(componentName)) {
-          Map<String, Object> m = expandUseParams(req, e.getValue());
-          e.setValue(m);
-        }
-      }
-
-      return map;
-    }
-
-    @SuppressWarnings({"unchecked"})
-    private Map<String, Object> expandUseParams(SolrQueryRequest req, Object plugin) {
-
-      Map<String, Object> pluginInfo = null;
-      if (plugin instanceof Map) {
-        pluginInfo = (Map) plugin;
-      } else if (plugin instanceof PluginInfo) {
-        pluginInfo = Utils.convertToMap((PluginInfo) plugin, new LinkedHashMap<>());
-      }
-      String useParams = (String) pluginInfo.get(USEPARAM);
-      String useParamsInReq = req.getOriginalParams().get(USEPARAM);
-      if (useParams != null || useParamsInReq != null) {
-        Map<String, Object> m = new LinkedHashMap<>();
-        pluginInfo.put("_useParamsExpanded_", m);
-        List<String> params = new ArrayList<>();
-        if (useParams != null) params.addAll(StrUtils.splitSmart(useParams, ','));
-        if (useParamsInReq != null) params.addAll(StrUtils.splitSmart(useParamsInReq, ','));
-        for (String param : params) {
-          RequestParams.ParamSet p =
-              this.req.getCore().getSolrConfig().getRequestParams().getParams(param);
-          if (p != null) {
-            m.put(param, p);
-          } else {
-            m.put(param, "[NOT AVAILABLE]");
-          }
-        }
-
-        SolrQueryRequest r = req.subRequest(req.getOriginalParams());
-        r.getContext().put(USEPARAM, useParams);
-        NamedList<?> nl = new PluginInfo(SolrRequestHandler.TYPE, pluginInfo).initArgs;
-        SolrPluginUtils.setDefaults(
-            r,
-            getSolrParamsFromNamedList(nl, DEFAULTS),
-            getSolrParamsFromNamedList(nl, APPENDS),
-            getSolrParamsFromNamedList(nl, INVARIANTS));
-        // SolrParams.wrapDefaults(maskUseParams, req.getParams())
-
-        MapSolrParams mask = new MapSolrParams(Map.of("componentName", "", "expandParams", ""));
-        pluginInfo.put("_effectiveParams_", SolrParams.wrapDefaults(mask, r.getParams()));
-      }
-      return pluginInfo;
-    }
-
     private void handlePOST() throws IOException {
       List<CommandOperation> ops = ApiBag.readCommands(req.getContentStreams(), resp.getValues());
       if (ops == null) return;

solr/core/src/java/org/apache/solr/handler/admin/api/GetConfig.java

@@ -68,6 +68,8 @@ public class GetConfig extends JerseyResource implements ConfigApi.Get {
           "searchComponent",
           "queryResponseWriter");
 
+  public static final String REQUEST_HANDLERS = "requestHandlers";
+
   // v2-only renames: external (URL/response-key) component name -> internal SolrConfig section
   // name. v1's GET /config/{component} keeps using the internal names unchanged.
   private static final Map<String, String> EXTERNAL_TO_INTERNAL_COMPONENT_NAME =
@@ -99,7 +101,7 @@ public GetConfig(SolrQueryRequest solrQueryRequest) {
   @PermissionName(CONFIG_READ_PERM)
   public ConfigInfoResponse getConfig(boolean expandParams) {
     final var response = instantiateJerseyResponse(ConfigInfoResponse.class);
-    response.config = buildConfigMap(solrQueryRequest, expandParams);
+    response.config = buildConfigMap(expandParams);
     return response;
   }
 
@@ -129,13 +131,37 @@ public ConfigZnodeVersionResponse getZnodeVersion(
     return response;
   }
 
+  @Override
+  @PermissionName(CONFIG_READ_PERM)
+  public ConfigInfoResponse getRequestHandler(
+      String componentName, boolean expandParams, boolean meta) {
+    return getRequestHandler(REQUEST_HANDLERS, componentName, expandParams, meta);
+  }
+
+  public ConfigInfoResponse getRequestHandler(
+      String sectionName, String componentName, boolean expandParams, boolean meta) {
+    final var response = instantiateJerseyResponse(ConfigInfoResponse.class);
+
+    Map<String, Object> configMap = new LinkedHashMap<>();
+    configMap.put(
+        sectionName, requestHandlersWithImplicits(solrConfigAsMap(), expandParams, componentName));
+    if (componentName != null) {
+      filterByComponentName(configMap, sectionName, componentName, meta, solrQueryRequest);
+    }
+
+    response.config = jsonSafeCopy(configMap);
+    return response;
+  }
+
   @Override
   @PermissionName(CONFIG_READ_PERM)
   public ConfigInfoResponse getConfigComponent(String component) {
     final var response = instantiateJerseyResponse(ConfigInfoResponse.class);
-    Map<String, Object> section = new LinkedHashMap<>();
-    section.put(component, solrConfigAsMap().get(toInternalComponentName(component)));
-    response.config = jsonSafeCopy(section);
+
+    Map<String, Object> configMap = new LinkedHashMap<>();
+    configMap.put(component, solrConfigAsMap().get(toInternalComponentName(component)));
+
+    response.config = jsonSafeCopy(configMap);
     return response;
   }
 
@@ -144,10 +170,11 @@ public ConfigInfoResponse getConfigComponent(String component) {
   public ConfigInfoResponse getConfigComponentByName(
       String component, String componentName, boolean meta) {
     final var response = instantiateJerseyResponse(ConfigInfoResponse.class);
-    Map<String, Object> section = new LinkedHashMap<>();
-    section.put(component, solrConfigAsMap().get(toInternalComponentName(component)));
-    filterByComponentName(section, component, componentName, meta, solrQueryRequest);
-    response.config = jsonSafeCopy(section);
+
+    Map<String, Object> configMap = new LinkedHashMap<>();
+    configMap.put(component, solrConfigAsMap().get(toInternalComponentName(component)));
+    filterByComponentName(configMap, component, componentName, meta, solrQueryRequest);
+    response.config = jsonSafeCopy(configMap);
     return response;
   }
 
@@ -161,12 +188,12 @@ public ConfigInfoResponse getConfigComponentByName(
    */
   @SuppressWarnings({"unchecked", "rawtypes"})
   public static void filterByComponentName(
-      Map<String, Object> section,
+      Map<String, Object> configMap,
       String component,
       String componentName,
       boolean meta,
       SolrQueryRequest req) {
-    Map pluginNameVsPluginInfo = (Map) section.get(component);
+    Map pluginNameVsPluginInfo = (Map) configMap.get(component);
     if (pluginNameVsPluginInfo == null) {
       return;
     }
@@ -183,7 +210,7 @@ public static void filterByComponentName(
 
     Map<String, Object> pluginInfo =
         o instanceof MapWriter ? new SimpleOrderedMap<>((MapWriter) o) : (Map<String, Object>) o;
-    section.put(
+    configMap.put(
         component,
         pluginNameVsPluginInfo instanceof MapWriter
             ? pluginInfo
@@ -227,29 +254,35 @@ private NullKeyTolerantMap jsonSafeCopy(Map<String, Object> map) {
     return jsonSafeCopy;
   }
 
-  @SuppressWarnings({"unchecked"})
-  private Map<String, Object> buildConfigMap(
-      SolrQueryRequest solrQueryRequest, boolean expandParams) {
-
+  private Map<String, Object> buildConfigMap(boolean expandParams) {
     Map<String, Object> configMap = solrConfigAsMap();
+    requestHandlersWithImplicits(configMap, expandParams, null);
+    return jsonSafeCopy(configMap);
+  }
 
-    Map<String, Object> reqHandlers =
+  @SuppressWarnings({"unchecked"})
+  private Map<String, Object> requestHandlersWithImplicits(
+      Map<String, Object> configMap, boolean expandParams, String expandOnlyComponentName) {
+    Map<String, Object> reqHandlersMap =
         (Map<String, Object>)
             configMap.computeIfAbsent(SolrRequestHandler.TYPE, k -> new LinkedHashMap<>());
+
     List<PluginInfo> plugins = solrQueryRequest.getCore().getImplicitHandlers();
     for (PluginInfo plugin : plugins) {
-      if (SolrRequestHandler.TYPE.equals(plugin.type) && !reqHandlers.containsKey(plugin.name)) {
-        reqHandlers.put(plugin.name, plugin);
+      if (SolrRequestHandler.TYPE.equals(plugin.type) && !reqHandlersMap.containsKey(plugin.name)) {
+        reqHandlersMap.put(plugin.name, plugin);
       }
     }
 
     if (expandParams) {
-      for (Map.Entry<String, Object> entry : reqHandlers.entrySet()) {
-        entry.setValue(expandUseParams(solrQueryRequest, entry.getValue()));
+      for (Map.Entry<String, Object> entry : reqHandlersMap.entrySet()) {
+        if (expandOnlyComponentName == null || expandOnlyComponentName.equals(entry.getKey())) {
+          entry.setValue(expandUseParams(solrQueryRequest, entry.getValue()));
+        }
       }
     }
 
-    return jsonSafeCopy(configMap);
+    return reqHandlersMap;
   }
 
   @SuppressWarnings({"unchecked", "rawtypes"})

solr/core/src/java/org/apache/solr/handler/admin/api/GetConfigAPI.java

@@ -61,7 +61,6 @@ public void getSingleParamSet(SolrQueryRequest req, SolrQueryResponse rsp) {
   @EndPoint(
       path = {
         "/config/luceneMatchVersion",
-        "/config/requestHandler",
         "/config/initParams",
         "/config/listener",
         "/config/requestDispatcher",

solr/core/src/test-files/solr/question-answer-repository/repository.json

@@ -28,9 +28,9 @@
                 "method": "POST"
               },
               "verify-command": {
-                "path": "/api/collections/${collection}/config/requestHandler?componentName=${RH-HANDLER-PATH}&meta=true",
+                "path": "/api/collections/${collection}/config/requestHandlers?componentName=${RH-HANDLER-PATH}&meta=true",
                 "method": "GET",
-                "condition": "$['config'].['requestHandler'].['${RH-HANDLER-PATH}'].['_packageinfo_'].['version']",
+                "condition": "$['config'].['requestHandlers'].['${RH-HANDLER-PATH}'].['_packageinfo_'].['version']",
                 "expected": "${package-version}"
               }
             }

solr/core/src/test/org/apache/solr/cli/PackageToolTest.java

@@ -320,9 +320,9 @@ void assertPackageVersion(
 
     testForResponseElement(
         cluster.getJettySolrRunner(0).getBaseUrl().toString() + "/" + collection,
-        "/config/requestHandler?componentName=" + component + "&meta=true",
+        "/config/requestHandlers?componentName=" + component + "&meta=true",
         credentials,
-        Arrays.asList("config", "requestHandler", component, "_packageinfo_", "version"),
+        Arrays.asList("config", "requestHandlers", component, "_packageinfo_", "version"),
         componentVersion);
   }
 

solr/core/src/test/org/apache/solr/cli/packagemanager/TestPackageManager.java

@@ -60,7 +60,7 @@ public void testWrongVerificationJPathIsThrown() throws IOException {
         plugin.verifyCommand = new SolrPackage.Command();
         plugin.verifyCommand.method = "GET";
         plugin.verifyCommand.path = /*"/api*/
-            "/collections/" + COLLECTION_NAME + "/config/requestHandler";
+            "/collections/" + COLLECTION_NAME + "/config/requestHandlers";
         plugin.verifyCommand.condition = "&[no_quotes_error_jpath]";
         manager.verify(
             new SolrPackageInstance(

solr/core/src/test/org/apache/solr/handler/admin/V2ConfigAPIMappingTest.java

@@ -49,7 +49,6 @@ public void populateApiBag() {
   // the API lookup works for a handful of the valid config "components".
   @Test
   public void testGetSingleComponentConfig() {
-    assertAnnotatedApiExistsFor("GET", "/config/requestHandler");
     assertAnnotatedApiExistsFor("GET", "/config/jmx");
     assertAnnotatedApiExistsFor("GET", "/config/requestDispatcher");
     assertAnnotatedApiExistsFor("GET", "/config/luceneMatchVersion");