From acdc3b2396d284186610e6020a148b722c88d630 Mon Sep 17 00:00:00 2001
From: Johan Wikman <johan.wikman@mariadb.com>
Date: Mon, 10 Jun 2019 19:07:12 +0300
Subject: [PATCH] MXS-2556 Add master configuration handling to SmartRouter

---
 .../routing/smartrouter/smartrouter.cc        | 76 ++++++++++++++++++-
 .../routing/smartrouter/smartrouter.hh        | 33 ++++++++
 .../routing/smartrouter/smartsession.cc       |  3 +
 3 files changed, 110 insertions(+), 2 deletions(-)

diff --git a/server/modules/routing/smartrouter/smartrouter.cc b/server/modules/routing/smartrouter/smartrouter.cc
index 4e9885eb7..ed9598222 100644
--- a/server/modules/routing/smartrouter/smartrouter.cc
+++ b/server/modules/routing/smartrouter/smartrouter.cc
@@ -16,6 +16,23 @@
 
 #include <maxscale/modutil.hh>
 
+namespace
+{
+
+namespace smartquery
+{
+
+config::Specification specification(MXS_MODULE_NAME, config::Specification::ROUTER);
+
+config::ParamServer
+master(&specification,
+       "master",
+       "The server/cluster to be treated as master, that is, the one where updates are sent.");
+
+}
+
+}
+
 /**
  * The module entry point.
  *
@@ -43,13 +60,68 @@ extern "C" MXS_MODULE* MXS_CREATE_MODULE()
         }
     };
 
+    SmartRouter::Config::populate(info);
+
     return &info;
 }
 
+SmartRouter::Config::Config()
+    : config::Configuration(&smartquery::specification)
+    , m_master(this, &smartquery::master)
+{
+}
+
+void SmartRouter::Config::populate(MXS_MODULE& module)
+{
+    smartquery::specification.populate(module);
+}
+
+bool SmartRouter::Config::configure(const MXS_CONFIG_PARAMETER& params)
+{
+    return smartquery::specification.configure(*this, params);
+}
+
+bool SmartRouter::Config::post_configure(const MXS_CONFIG_PARAMETER& params)
+{
+    bool rv = true;
+
+    auto servers = params.get_server_list(CN_SERVERS);
+    // TODO: Check that the servers are local ones.
+
+    auto it = std::find(servers.begin(), servers.end(), m_master.get());
+
+    if (it == servers.end())
+    {
+        rv = false;
+
+        std::string s;
+
+        for (auto server : servers)
+        {
+            if (!s.empty())
+            {
+                s+= ", ";
+            }
+
+            s += server->name();
+        }
+
+        MXS_ERROR("The master server %s, is not one of the servers (%s) of the service.",
+                  m_master.get()->name(), s.c_str());
+    }
+
+    return rv;
+}
+
 bool SmartRouter::configure(MXS_CONFIG_PARAMETER* pParams)
 {
-    // TODO ensure Servers are internal ones. Later TODO call routers directly.
-    return true;
+    if (!smartquery::specification.validate(*pParams))
+    {
+        return false;
+    }
+
+    // Since post_configure() has been overriden, this may fail.
+    return m_config.configure(*pParams);
 }
 
 SERVICE* SmartRouter::service() const
diff --git a/server/modules/routing/smartrouter/smartrouter.hh b/server/modules/routing/smartrouter/smartrouter.hh
index 526a5a9ed..e582c4e48 100644
--- a/server/modules/routing/smartrouter/smartrouter.hh
+++ b/server/modules/routing/smartrouter/smartrouter.hh
@@ -19,6 +19,7 @@
  */
 
 #include <maxscale/ccdefs.hh>
+#include <maxscale/config2.hh>
 #include <maxscale/router.hh>
 
 class SmartRouterSession;
@@ -28,6 +29,30 @@ class SmartRouterSession;
 class SmartRouter : public mxs::Router<SmartRouter, SmartRouterSession>
 {
 public:
+    class Config : public config::Configuration
+    {
+    public:
+        Config();
+
+        Config(const Config&) = delete;
+        Config& operator=(const Config&) = delete;
+
+        static void populate(MXS_MODULE& module);
+
+        bool configure(const MXS_CONFIG_PARAMETER& params);
+
+        SERVER* master() const
+        {
+            return m_master.get();
+        }
+
+    private:
+        bool post_configure(const MXS_CONFIG_PARAMETER& params) override;
+
+    private:
+        config::Server  m_master;
+    };
+
     static SmartRouter* create(SERVICE* pService, MXS_CONFIG_PARAMETER* pParams);
 
     SmartRouterSession* newSession(MXS_SESSION* pSession);
@@ -38,6 +63,14 @@ public:
     bool     configure(MXS_CONFIG_PARAMETER* pParams);
 
     SERVICE* service() const;
+
+    const Config& config() const
+    {
+        return m_config;
+    }
+
 private:
     SmartRouter(SERVICE* service);
+
+    Config m_config;
 };
diff --git a/server/modules/routing/smartrouter/smartsession.cc b/server/modules/routing/smartrouter/smartsession.cc
index 4518814b9..0425c8d09 100644
--- a/server/modules/routing/smartrouter/smartsession.cc
+++ b/server/modules/routing/smartrouter/smartsession.cc
@@ -121,6 +121,9 @@ SmartRouterSession* SmartRouterSession::create(SmartRouter* pRouter, MXS_SESSION
 {
     Clusters clusters;
 
+    SERVER* pMaster = pRouter->config().master();
+    // TODO: Use pMaster below.
+
     bool is_master = true;  // TODO this will be read from config
     int master_pos = 0;     //      and this will be initialized to the position of the master