Switch from rpm to yum

cr: https://code.amazon.com/reviews/CR-117320135

Author: armnejad

Tools/src/update/linux/install.sh

@@ -20,15 +20,58 @@ if [ "$1" == "register-managed-instance" ]; then
   fi
 fi
 
-# allow ssm-agent to finish it's work
+# allow ssm-agent to finish its work
 sleep 2
 
+PACKAGE_MANAGER='rpm'
+
+# sets PACKAGE_MANAGER value to name of package manager
+# that is passed in as long as it is present on the OS
+function check_binary
+{
+    which $1 2>/dev/null
+    RET_CODE=$?
+    if [ ${RET_CODE} == 0 ];
+    then
+      PACKAGE_MANAGER=$1
+      echo "Package manager found. Using ${PACKAGE_MANAGER}  to install amazon-ssm-agent."
+    fi
+}
+
+check_binary yum
+if [ ${PACKAGE_MANAGER} == "yum" ];
+then
+  INSTALL_COMMAND="yum -y localinstall amazon-ssm-agent.rpm"
+else
+  INSTALL_COMMAND="rpm -U amazon-ssm-agent.rpm"
+fi
+
+function install_agent
+{
+  echo "Installing agent using ${INSTALL_COMMAND}."
+  pmOutput=$(${INSTALL_COMMAND} 2>&1)
+  pmExit=$?
+  echo "Package Manager Output: $pmOutput"
+}
+
+function check_error_code
+{
+  if [ "$pmExit" -ne 0 ]; then
+    # messages returned by rpm / yum when trying to install package that is already installed
+    if [[ $pmOutput == *"is already installed"* ]] || [[ $pmOutput == *"does not update installed package"* ]]; then
+      echo "Install was successful"
+      exit 0
+    fi
+
+    echo "Package manager failed with exit code '$pmExit'"
+    echo "Package manager output: $pmOutput"
+    exit 125
+  fi
+}
+
 if [[ $(/sbin/init --version 2> /dev/null) =~ upstart ]]; then
   echo "upstart detected"
-  echo "Installing agent"
-  pmOutput=$(rpm -U amazon-ssm-agent.rpm 2>&1)
-  pmExit=$?
-  echo "RPM Output: $pmOutput"
+  install_agent
 
   if [ "$DO_REGISTER" = true ]; then
 		/sbin/stop amazon-ssm-agent
@@ -42,16 +85,8 @@ if [[ $(/sbin/init --version 2> /dev/null) =~ upstart ]]; then
   /sbin/start amazon-ssm-agent
   status amazon-ssm-agent
 
-  if [ "$pmExit" -ne 0 ]; then
-    if [[ $pmOutput == *"is already installed"* ]]; then
-      echo "Install was successfull"
-      exit 0
-    fi
+  check_error_code
 
-    echo "Package manager failed with exit code '$pmExit'"
-    echo "Package manager output: $pmOutput"
-    exit 125
-  fi
 elif [[ $(systemctl 2> /dev/null) =~ -\.mount ]]; then
   if [[ "$(systemctl is-active amazon-ssm-agent.service)" == "active" ]]; then
     echo "-> Agent is running in the instance"
@@ -66,10 +101,7 @@ elif [[ $(systemctl 2> /dev/null) =~ -\.mount ]]; then
 
   originalSvc=$(systemctl show -p FragmentPath amazon-ssm-agent.service)
 
-  echo "Installing agent"
-  pmOutput=$(rpm -U amazon-ssm-agent.rpm 2>&1)
-  pmExit=$?
-  echo "RPM Output: $pmOutput"
+  install_agent
 
   updatedSvc=$(systemctl show -p FragmentPath amazon-ssm-agent.service)
   if ! [ -z "$originalSvc" ] && ! [ -z "$updatedSvc" ]; then
@@ -100,17 +132,8 @@ elif [[ $(systemctl 2> /dev/null) =~ -\.mount ]]; then
   systemctl start amazon-ssm-agent.service
   systemctl status amazon-ssm-agent.service
 
-  if [ "$pmExit" -ne 0 ]; then
-    if [[ $pmOutput == *"is already installed"* ]]; then
-      echo "Install was successful"
-      exit 0
-    fi
-
-    echo "Package manager failed with exit code '$pmExit'"
-    echo "Package manager output: $pmOutput"
-    exit 125
-  fi
+  check_error_code
 else
   echo "The amazon-ssm-agent is not supported on this platform. Please visit the documentation for the list of supported platforms" 1>&2
   exit 124
-fi
+fi

Tools/src/update/linux/uninstall.sh

@@ -11,12 +11,35 @@ function error_exit
   exit 1
 }
 
+PACKAGE_MANAGER='rpm'
+
+# sets PACKAGE_MANAGER value to name of package manager
+# that is passed in as long as it is present on the OS
+function check_binary
+{
+    which $1 2>/dev/null
+    RET_CODE=$?
+    if [ ${RET_CODE} == 0 ];
+    then
+      PACKAGE_MANAGER=$1
+      echo "Package manager found. Using ${PACKAGE_MANAGER}  to install amazon-ssm-agent."
+    fi
+}
+
+check_binary yum
+if [ ${PACKAGE_MANAGER} == "yum" ];
+then
+  UNINSTALL_COMMAND="yum -y remove amazon-ssm-agent"
+else
+  UNINSTALL_COMMAND="rpm --erase amazon-ssm-agent"
+fi
+
 if [[ $(/sbin/init --version 2> /dev/null) =~ upstart ]]; then
   echo "Checking if the agent is installed"
   if [ "$(rpm -q amazon-ssm-agent)" != "package amazon-ssm-agent is not installed" ]; then
 		echo "-> Agent is installed in this instance"
-		echo "Uninstalling the agent"
-		rpm --erase amazon-ssm-agent
+		echo "Uninstalling the agent using ${UNINSTALL_COMMAND}"
+		${UNINSTALL_COMMAND}
 		sleep 1
   else
 		echo "-> Agent is not installed in this instance"
@@ -25,8 +48,8 @@ elif [[ $(systemctl 2> /dev/null) =~ -\.mount ]]; then
   echo "Checking if the agent is installed"
   if [[ "$(systemctl status amazon-ssm-agent.service)" != *"Loaded: not-found"* ]]; then
 		echo "-> Agent is installed in this instance"
-		echo "Uninstalling the agent"
-		rpm --erase amazon-ssm-agent
+		echo "Uninstalling the agent using ${UNINSTALL_COMMAND}"
+		${UNINSTALL_COMMAND}
 		sleep 1
   else
 		echo "-> Agent is not installed in this instance"