Merge pull request #11 from TimSimpsonR/set_failed_if_mysql_install_f…

…ails Set the service status to FAILED if the MySQL install failed.
hub-cap · Jul 10, 2012 · 7b788da · 7b788da
2 parents 4a20371 + ffb9f67
commit 7b788da
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Showing 4 changed files with 46 additions and 32 deletions.
diff --git a/src/nova/guest/mysql/MySqlApp.cc b/src/nova/guest/mysql/MySqlApp.cc
@@ -1,5 +1,6 @@
 #include "nova/guest/mysql/MySqlApp.h"
 #include "nova/guest/apt.h"
+#include <exception>
 #include <boost/format.hpp>
 #include <fstream>
 #include "nova/utils/io.h"
@@ -173,38 +174,35 @@ void MySqlApp::install_and_secure(AptGuest & apt, int memory_mb) {
     NOVA_LOG_INFO("Updating status to BUILDING...");
     status->begin_mysql_install();
 
-    // You may wonder why there's no try / catch around this section which
-    // would change status to a failure state if something went wrong.
-    // The reason why is that the Reddwarf compute manager will time out the
-    // instance. If we added a catch here, it would be harder to test this
-    // ability of the Reddwarf compute manager. We may find a way to add error
-    // handling here anyway as it would speed up acknowledgement of failures,
-    // but the bigger priority is making sure the manager retains the ability
-    // to determine when a guest is misbehaving.
-
-    NOVA_LOG_INFO("Preparing Guest as MySQL Server");
-    install_mysql(apt);
-
-    string admin_password = mysql::generate_password();
-
-    NOVA_LOG_INFO("Generating root password...");
-    generate_root_password(local_db);
-    NOVA_LOG_INFO("Removing anonymous users...");
-    remove_anonymous_user(local_db);
-    NOVA_LOG_INFO("Removing root access...");
-    remove_remote_root_access(local_db);
-    NOVA_LOG_INFO("Creating admin user...");
-    create_admin_user(local_db, admin_password);
-    NOVA_LOG_INFO("Flushing privileges");
-    local_db.get_connection()->flush_privileges();
-    local_db.get_connection()->close();
+    try {
+        NOVA_LOG_INFO("Preparing Guest as MySQL Server");
+        install_mysql(apt);
 
-    internal_stop_mysql();
-    write_mycnf(apt, memory_mb, admin_password);
-    start_mysql();
+        string admin_password = mysql::generate_password();
+
+        NOVA_LOG_INFO("Generating root password...");
+        generate_root_password(local_db);
+        NOVA_LOG_INFO("Removing anonymous users...");
+        remove_anonymous_user(local_db);
+        NOVA_LOG_INFO("Removing root access...");
+        remove_remote_root_access(local_db);
+        NOVA_LOG_INFO("Creating admin user...");
+        create_admin_user(local_db, admin_password);
+        NOVA_LOG_INFO("Flushing privileges");
+        local_db.get_connection()->flush_privileges();
+        local_db.get_connection()->close();
 
-    status->end_install_or_restart();
-    NOVA_LOG_INFO("Dbaas preparation complete.");
+        internal_stop_mysql();
+        write_mycnf(apt, memory_mb, admin_password);
+        start_mysql();
+
+        status->end_install_or_restart();
+        NOVA_LOG_INFO("Dbaas preparation complete.");
+    } catch(const std::exception & e) {
+        NOVA_LOG_ERROR2("Error installing MySQL!: %s", e.what());
+        status->end_failed_install();
+        throw;
+    }
 }
 
 void MySqlApp::install_mysql(AptGuest & apt) {

diff --git a/src/nova/guest/mysql/MySqlAppStatus.cc b/src/nova/guest/mysql/MySqlAppStatus.cc
@@ -105,6 +105,12 @@ optional<string> MySqlAppStatus::find_mysql_pid_file() const {
     return rtn;
 }
 
+void MySqlAppStatus::end_failed_install() {
+    boost::lock_guard<boost::mutex> lock(nova_db_mutex);
+    this->restart_mode = false;
+    this->set_status(FAILED);
+}
+
 void MySqlAppStatus::end_install_or_restart() {
     boost::lock_guard<boost::mutex> lock(nova_db_mutex);
     this->restart_mode = false;

diff --git a/src/nova/guest/mysql/MySqlAppStatus.h b/src/nova/guest/mysql/MySqlAppStatus.h
@@ -71,6 +71,10 @@ namespace nova { namespace guest { namespace mysql {
             /* Called before restarting MYSQL. */
             void begin_mysql_restart();
 
+            /* Called when MySQL failed to install. Updates Nova DB to
+             * FAILED. */
+            void end_failed_install();
+
             /* Called after MySQL is installed or restarted. Updates the Nova
              * DB with the actual MySQL status. */
             void end_install_or_restart();

diff --git a/tests/nova/guest/mysql/MySqlAppStatus_tests.cc b/tests/nova/guest/mysql/MySqlAppStatus_tests.cc
@@ -150,7 +150,7 @@ BOOST_AUTO_TEST_CASE(When_row_is_in_build_state) {
 
 BOOST_AUTO_TEST_CASE(When_row_is_in_fail_state) {
     CHECK_POINT();
-    updater.set_status(MySqlAppStatus::FAILED);
+    updater.end_failed_install();
 
     BOOST_CHECK_EQUAL(updater.is_mysql_installed(), false);
     BOOST_CHECK_EQUAL(!updater.get_status_from_nova_db(), false);
@@ -166,6 +166,9 @@ BOOST_AUTO_TEST_CASE(When_row_is_in_fail_state) {
 }
 
 BOOST_AUTO_TEST_CASE(After_mysql_is_marked_as_installed_and_mysql_pingable) {
+    // This class mocks MySQL being pingable and working, by making
+    // "on_execute" not throw anything. So this simulates what happens in
+    // the code when MySQL can be pinged.
     struct Mock : public virtual MySqlAppStatusDefaultTestContext {
         virtual void on_execute(std::stringstream & out, int call_number)
         const {
@@ -190,7 +193,10 @@ BOOST_AUTO_TEST_CASE(After_mysql_is_marked_as_installed_and_mysql_pingable) {
 
 BOOST_AUTO_TEST_CASE(After_mysql_is_marked_as_installed_and_mysql_blocked) {
     updater.begin_mysql_install(); // Just to be different.
-
+    // This class mocks MySQL being pingable and working for the first call,
+    // but the second time throws an exception. This is simulates what happens
+    // when MySQL is "blocked" - the first ping fails, but the second
+    // process calls work.
     struct Mock : public virtual MySqlAppStatusDefaultTestContext {
         virtual void on_execute(std::stringstream & out, int call_number) const
         {