MXS-2969: Restart MaxScale on upgrade

Renamed the postrm script to prerm since it is executed before
uninstallation.

Silenced the output of the systemctl disable commands and added a
conditional restart of MaxScale if a MaxScale instance is running.

Use getent instead of grep to detect if the maxscale user needs to be
created.

CMakeLists.txt

@@ -119,7 +119,7 @@ configure_file(${CMAKE_SOURCE_DIR}/include/maxscale/paths.h.in ${CMAKE_BINARY_DI
 configure_file(${CMAKE_SOURCE_DIR}/include/maxscale/adminusers.h.in ${CMAKE_BINARY_DIR}/include/maxscale/adminusers.h @ONLY)
 configure_file(${CMAKE_SOURCE_DIR}/server/test/maxscale_test.h.in ${CMAKE_BINARY_DIR}/include/maxscale/maxscale_test.h @ONLY)
 configure_file(${CMAKE_SOURCE_DIR}/etc/postinst.in ${CMAKE_BINARY_DIR}/postinst @ONLY)
-configure_file(${CMAKE_SOURCE_DIR}/etc/postrm.in ${CMAKE_BINARY_DIR}/postrm @ONLY)
+configure_file(${CMAKE_SOURCE_DIR}/etc/prerm.in ${CMAKE_BINARY_DIR}/prerm @ONLY)
 configure_file(${CMAKE_SOURCE_DIR}/etc/upstart/maxscale.conf.in ${CMAKE_BINARY_DIR}/upstart/maxscale.conf @ONLY)
 configure_file(${CMAKE_SOURCE_DIR}/test/maxscale_test.cnf ${CMAKE_BINARY_DIR}/maxscale.cnf @ONLY)
 configure_file(${CMAKE_SOURCE_DIR}/test/maxscale_test_secondary.cnf ${CMAKE_BINARY_DIR}/maxscale_secondary.cnf @ONLY)
@@ -256,7 +256,7 @@ if(PACKAGE)
   install_program(${CMAKE_BINARY_DIR}/maxscale core)
   install_file(${CMAKE_BINARY_DIR}/maxscale.conf core)
   install_program(${CMAKE_BINARY_DIR}/postinst core)
-  install_program(${CMAKE_BINARY_DIR}/postrm core)
+  install_program(${CMAKE_BINARY_DIR}/prerm core)
 
   # The inclusion of CPack needs to be the last effective packaging related command. All
   # configurations to packaging done after the call will be ignored.

cmake/package.cmake

@@ -105,5 +105,5 @@ else()
   endif()
 
   message(STATUS "You can install startup scripts and system configuration files for MaxScale by running the 'postinst' shell script located at ${CMAKE_INSTALL_PREFIX}.")
-  message(STATUS "To remove these installed files, run the 'postrm' shell script located in the same folder.")
+  message(STATUS "To remove these installed files, run the 'prerm' shell script located in the same folder.")
 endif()

cmake/package_deb.cmake

@@ -6,7 +6,7 @@ set(CPACK_DEBIAN_PACKAGE_FILE_NAME "${CPACK_PACKAGE_NAME}")
 
 if(TARGET_COMPONENT STREQUAL "core" OR TARGET_COMPONENT STREQUAL "all")
   set(CPACK_DEBIAN_PACKAGE_SHLIBDEPS ON)
-  set(CPACK_DEBIAN_PACKAGE_CONTROL_EXTRA "${CMAKE_BINARY_DIR}/postinst;${CMAKE_BINARY_DIR}/postrm")
+  set(CPACK_DEBIAN_PACKAGE_CONTROL_EXTRA "${CMAKE_BINARY_DIR}/postinst;${CMAKE_BINARY_DIR}/prerm")
 elseif(TARGET_COMPONENT STREQUAL "devel")
   set(CPACK_DEBIAN_PACKAGE_DESCRIPTION "${CPACK_PACKAGE_DESCRIPTION_SUMMARY}\n${DESCRIPTION_TEXT}")
 endif()

cmake/package_rpm.cmake

@@ -39,7 +39,7 @@ set(CPACK_RPM_USER_FILELIST "${IGNORED_DIRS}")
 
 if(TARGET_COMPONENT STREQUAL "core" OR TARGET_COMPONENT STREQUAL "all")
   set(CPACK_RPM_POST_INSTALL_SCRIPT_FILE ${CMAKE_BINARY_DIR}/postinst)
-  set(CPACK_RPM_PRE_UNINSTALL_SCRIPT_FILE ${CMAKE_BINARY_DIR}/postrm)
+  set(CPACK_RPM_PRE_UNINSTALL_SCRIPT_FILE ${CMAKE_BINARY_DIR}/prerm)
 endif()
 
 if(EXTRA_PACKAGE_DEPENDENCIES)

etc/postinst.in

@@ -12,8 +12,9 @@ mkdir -p @MAXSCALE_VARDIR@/lib/maxscale
 mkdir -p @MAXSCALE_VARDIR@/cache/maxscale
 mkdir -p @MAXSCALE_VARDIR@/run/maxscale
 
-# Create MaxScale user
+# Create MaxScale user if it doesnt' exist
-if [ -f "/etc/passwd" ] && [ "$(grep -c 'maxscale' /etc/passwd)" -eq 0 ]
+getent passwd maxscale > /dev/null
+if [ $? -eq 0 ]
 then
     groupadd -r maxscale
     useradd -r -s /bin/false -g maxscale maxscale
@@ -63,7 +64,9 @@ then
     fi
 
     mkdir -p /etc/systemd/system/maxscale.service.d
-    systemctl enable maxscale.service
+    systemctl enable maxscale.service > /dev/null
+
+    systemctl is-active maxscale.service --quiet && systemctl restart maxscale.service
 else
     if [ -d "/etc/init/" ] && [ -f "@CMAKE_INSTALL_PREFIX@/@MAXSCALE_SHAREDIR@/upstart/maxscale.conf" ]
     then
@@ -77,6 +80,8 @@ else
     else
         echo "Could not find init script: @CMAKE_INSTALL_PREFIX@/@MAXSCALE_SHAREDIR@/maxscale" >& 2
     fi
+
+    service maxscale status > /dev/null && service maxscale restart > /dev/null
 fi
 
 # If no maxscale.cnf file is found in /etc, copy the template file there

etc/prerm.in

@@ -19,13 +19,15 @@ then
     if [ -f /usr/lib/systemd/system/maxscale.service ]
     then
         systemctl stop maxscale.service
-        systemctl disable maxscale.service
+        systemctl disable maxscale.service > /dev/null
         rm /usr/lib/systemd/system/maxscale.service
+        systemctl daemon-reload
     elif [ -f /lib/systemd/system/maxscale.service ]
     then
         systemctl stop maxscale.service
-        systemctl disable maxscale.service
+        systemctl disable maxscale.service > /dev/null
         rm /lib/systemd/system/maxscale.service
+        systemctl daemon-reload
     fi
 
     if [ -f /etc/logrotate.d/maxscale_logrotate ]