Merge #10150: [rpc] Add logging rpc

7fd50c3 allow libevent logging to be updated during runtime (John Newbery)
5255aca [rpc] Add logging RPC (John Newbery)
4d9950d Set BCLog::LIBEVENT correctly for old libevent versions. (John Newbery)

Tree-SHA512: d6788a7205372c0528da71eca052910dfb055f2940ca884f422ff3db66e23a2b49c6a15b8f27d5255554fe5c5a928f5dd903fdc63b0bd6c8fa7783e77bb30fe8

src/rpc/client.cpp

@@ -113,6 +113,8 @@ static const CRPCConvertParam vRPCConvertParams[] =
     { "getmempoolancestors", 1, "verbose" },
     { "getmempooldescendants", 1, "verbose" },
     { "bumpfee", 1, "options" },
+    { "logging", 0, "include" },
+    { "logging", 1, "exclude" },
     // Echo with conversion (For testing only)
     { "echojson", 0, "arg0" },
     { "echojson", 1, "arg1" },

src/rpc/misc.cpp

@@ -7,6 +7,7 @@
 #include "clientversion.h"
 #include "init.h"
 #include "validation.h"
+#include "httpserver.h"
 #include "net.h"
 #include "netbase.h"
 #include "rpc/blockchain.h"
@@ -555,6 +556,73 @@ UniValue getmemoryinfo(const JSONRPCRequest& request)
     }
 }
 
+uint32_t getCategoryMask(UniValue cats) {
+    cats = cats.get_array();
+    uint32_t mask = 0;
+    for (unsigned int i = 0; i < cats.size(); ++i) {
+        uint32_t flag = 0;
+        std::string cat = cats[i].get_str();
+        if (!GetLogCategory(&flag, &cat)) {
+            throw JSONRPCError(RPC_INVALID_PARAMETER, "unknown logging category " + cat);
+        }
+        mask |= flag;
+    }
+    return mask;
+}
+
+UniValue logging(const JSONRPCRequest& request)
+{
+    if (request.fHelp || request.params.size() > 2) {
+        throw std::runtime_error(
+            "logging [include,...] <exclude>\n"
+            "Gets and sets the logging configuration.\n"
+            "When called without an argument, returns the list of categories that are currently being debug logged.\n"
+            "When called with arguments, adds or removes categories from debug logging.\n"
+            "The valid logging categories are: " + ListLogCategories() + "\n"
+            "libevent logging is configured on startup and cannot be modified by this RPC during runtime."
+            "Arguments:\n"
+            "1. \"include\" (array of strings) add debug logging for these categories.\n"
+            "2. \"exclude\" (array of strings) remove debug logging for these categories.\n"
+            "\nResult: <categories>  (string): a list of the logging categories that are active.\n"
+            "\nExamples:\n"
+            + HelpExampleCli("logging", "\"[\\\"all\\\"]\" \"[\\\"http\\\"]\"")
+            + HelpExampleRpc("logging", "[\"all\"], \"[libevent]\"")
+        );
+    }
+
+    uint32_t originalLogCategories = logCategories;
+    if (request.params.size() > 0 && request.params[0].isArray()) {
+        logCategories |= getCategoryMask(request.params[0]);
+    }
+
+    if (request.params.size() > 1 && request.params[1].isArray()) {
+        logCategories &= ~getCategoryMask(request.params[1]);
+    }
+
+    // Update libevent logging if BCLog::LIBEVENT has changed.
+    // If the library version doesn't allow it, UpdateHTTPServerLogging() returns false,
+    // in which case we should clear the BCLog::LIBEVENT flag.
+    // Throw an error if the user has explicitly asked to change only the libevent
+    // flag and it failed.
+    uint32_t changedLogCategories = originalLogCategories ^ logCategories;
+    if (changedLogCategories & BCLog::LIBEVENT) {
+        if (!UpdateHTTPServerLogging(logCategories & BCLog::LIBEVENT)) {
+            logCategories &= ~BCLog::LIBEVENT;
+            if (changedLogCategories == BCLog::LIBEVENT) {
+            throw JSONRPCError(RPC_INVALID_PARAMETER, "libevent logging cannot be updated when using libevent before v2.1.1.");
+            }
+        }
+    }
+
+    UniValue result(UniValue::VOBJ);
+    std::vector<CLogCategoryActive> vLogCatActive = ListActiveLogCategories();
+    for (const auto& logCatActive : vLogCatActive) {
+        result.pushKV(logCatActive.category, logCatActive.active);
+    }
+
+    return result;
+}
+
 UniValue echo(const JSONRPCRequest& request)
 {
     if (request.fHelp)
@@ -581,7 +649,8 @@ static const CRPCCommand commands[] =
     /* Not shown in help */
     { "hidden",             "setmocktime",            &setmocktime,            true,  {"timestamp"}},
     { "hidden",             "echo",                   &echo,                   true,  {"arg0","arg1","arg2","arg3","arg4","arg5","arg6","arg7","arg8","arg9"}},
-    { "hidden",             "echojson",               &echo,                  true,  {"arg0","arg1","arg2","arg3","arg4","arg5","arg6","arg7","arg8","arg9"}},
+    { "hidden",             "echojson",               &echo,                   true,  {"arg0","arg1","arg2","arg3","arg4","arg5","arg6","arg7","arg8","arg9"}},
+    { "hidden",             "logging",                &logging,                true,  {"include", "exclude"}},
 };
 
 void RegisterMiscRPCCommands(CRPCTable &t)