Fixed install/remove of telegraf on non-systemd Debian/Ubuntu systems (#2360)

CHANGELOG.md

@@ -85,6 +85,7 @@ be deprecated eventually.
 - [#2356](https://github.com/influxdata/telegraf/issues/2356): cpu input panic when /proc/stat is empty.
 - [#2341](https://github.com/influxdata/telegraf/issues/2341): telegraf swallowing panics in --test mode.
 - [#2358](https://github.com/influxdata/telegraf/pull/2358): Create pidfile with 644 permissions & defer file deletion.
+- [#2360](https://github.com/influxdata/telegraf/pull/2360): Fixed install/remove of telegraf on non-systemd Debian/Ubuntu systems
 - [#2282](https://github.com/influxdata/telegraf/issues/2282): Reloading telegraf freezes prometheus output.
 - [#2390](https://github.com/influxdata/telegraf/issues/2390): Empty tag value causes error on InfluxDB output.
 - [#2380](https://github.com/influxdata/telegraf/issues/2380): buffer_size field value is negative number from "internal" plugin.

scripts/post-install.sh

@@ -24,10 +24,8 @@ function install_chkconfig {
     chkconfig --add telegraf
 }
 
-id telegraf &>/dev/null
-if [[ $? -ne 0 ]]; then
-    grep "^telegraf:" /etc/group &>/dev/null
-    if [[ $? -ne 0 ]]; then
+if ! id telegraf &>/dev/null; then
+    if ! grep "^telegraf:" /etc/group &>/dev/null; then
         useradd -r -K USERGROUPS_ENAB=yes -M telegraf -s /bin/false -d /etc/telegraf
     else
         useradd -r -K USERGROUPS_ENAB=yes -M telegraf -s /bin/false -d /etc/telegraf -g telegraf
@@ -60,24 +58,32 @@ fi
 # Distribution-specific logic
 if [[ -f /etc/redhat-release ]]; then
     # RHEL-variant logic
-    which systemctl &>/dev/null
-    if [[ $? -eq 0 ]]; then
+    if [[ "$(readlink /proc/1/exe)" == */systemd ]]; then
         install_systemd
     else
-	    # Assuming sysv
+        # Assuming SysVinit
         install_init
+        # Run update-rc.d or fallback to chkconfig if not available
+        if which update-rc.d &>/dev/null; then
+            install_update_rcd
+        else
             install_chkconfig
         fi
+    fi
 elif [[ -f /etc/debian_version ]]; then
     # Debian/Ubuntu logic
-    which systemctl &>/dev/null
-    if [[ $? -eq 0 ]]; then
+    if [[ "$(readlink /proc/1/exe)" == */systemd ]]; then
         install_systemd
         systemctl restart telegraf || echo "WARNING: systemd not running."
     else
-	    # Assuming sysv
+	    # Assuming SysVinit
         install_init
+        # Run update-rc.d or fallback to chkconfig if not available
+        if which update-rc.d &>/dev/null; then
             install_update_rcd
+        else
+            install_chkconfig
+        fi
         invoke-rc.d telegraf restart
     fi
 elif [[ -f /etc/os-release ]]; then
@@ -85,6 +91,11 @@ elif [[ -f /etc/os-release ]]; then
     if [[ $ID = "amzn" ]]; then
 	    # Amazon Linux logic
         install_init
+        # Run update-rc.d or fallback to chkconfig if not available
+        if which update-rc.d &>/dev/null; then
+            install_update_rcd
+        else
             install_chkconfig
         fi
+    fi
 fi

scripts/post-remove.sh

@@ -15,28 +15,45 @@ function disable_chkconfig {
     rm -f /etc/init.d/telegraf
 }
 
-if [[ "$1" == "0" ]]; then
-    # RHEL and any distribution that follow RHEL, Amazon Linux covered
-    # telegraf is no longer installed, remove from init system
+if [[ -f /etc/redhat-release ]]; then
+    # RHEL-variant logic
+    if [[ "$1" = "0" ]]; then
+        # InfluxDB is no longer installed, remove from init system
         rm -f /etc/default/telegraf
 
-    which systemctl &>/dev/null
-    if [[ $? -eq 0 ]]; then
+        if [[ "$(readlink /proc/1/exe)" == */systemd ]]; then
             disable_systemd
         else
             # Assuming sysv
             disable_chkconfig
         fi
-elif [ "$1" == "remove" -o "$1" == "purge" ]; then
+    fi
+elif [[ -f /etc/debian_version ]]; then
     # Debian/Ubuntu logic
+    if [ "$1" == "remove" -o "$1" == "purge" ]; then
         # Remove/purge
         rm -f /etc/default/telegraf
 
-    which systemctl &>/dev/null
-    if [[ $? -eq 0 ]]; then
+        if [[ "$(readlink /proc/1/exe)" == */systemd ]]; then
             disable_systemd
         else
             # Assuming sysv
+            # Run update-rc.d or fallback to chkconfig if not available
+            if which update-rc.d &>/dev/null; then
                 disable_update_rcd
+            else
+                disable_chkconfig
+            fi
+        fi
+    fi
+elif [[ -f /etc/os-release ]]; then
+    source /etc/os-release
+    if [[ $ID = "amzn" ]]; then
+        # Amazon Linux logic
+        if [[ "$1" = "0" ]]; then
+            # InfluxDB is no longer installed, remove from init system
+            rm -f /etc/default/telegraf
+            disable_chkconfig
+        fi
     fi
 fi

scripts/pre-install.sh

@@ -1,14 +1,16 @@
 #!/bin/bash
 
-if [[ -f /etc/opt/telegraf/telegraf.conf ]]; then
+if [[ -d /etc/opt/telegraf ]]; then
     # Legacy configuration found
     if [[ ! -d /etc/telegraf ]]; then
         # New configuration does not exist, move legacy configuration to new location
         echo -e "Please note, Telegraf's configuration is now located at '/etc/telegraf' (previously '/etc/opt/telegraf')."
-	mv /etc/opt/telegraf /etc/telegraf
+        mv -vn /etc/opt/telegraf /etc/telegraf
 
+        if [[ -f /etc/telegraf/telegraf.conf ]]; then
             backup_name="telegraf.conf.$(date +%s).backup"
-	echo "A backup of your current configuration can be found at: /etc/telegraf/$backup_name"
-	cp -a /etc/telegraf/telegraf.conf /etc/telegraf/$backup_name
+            echo "A backup of your current configuration can be found at: /etc/telegraf/${backup_name}"
+            cp -a "/etc/telegraf/telegraf.conf" "/etc/telegraf/${backup_name}"
+        fi
     fi
 fi

scripts/pre-remove.sh

@@ -5,8 +5,7 @@ BIN_DIR=/usr/bin
 # Distribution-specific logic
 if [[ -f /etc/debian_version ]]; then
     # Debian/Ubuntu logic
-    which systemctl &>/dev/null
-    if [[ $? -eq 0 ]]; then
+    if [[ "$(readlink /proc/1/exe)" == */systemd ]]; then
         deb-systemd-invoke stop telegraf.service
     else
         # Assuming sysv