Add better checks for existing installs to the kickstart scripts. (#9408)

* Added better checks for existing installs to the kickstart scripts.

This adds more robust checks to our Kickstart install scripts to prevent
users from accidentally installing Netdata over top of an existing
install (which can lead to all kinds of problematic situations).

The logic for these checks works as follows:

- See if `netdata` is located somewhere in `$PATH` (using `command -v`),
  and if present assume there's an existing install.
- Otherwise, check if `/opt/netdata/bin/netdata` exists, if so assume
  there's an existing install, otherwise continue under the assumption
  there isn't.
- If there is an existing install, check if it's one done through our
  install scripts, if not stop the installation process.
- If it is one of our installs, look for and attempt to use the updater
  script to update the existing install (exiting with an error message
  if that fails).

This also adds a switch called '--allow-duplicate-install' which will
cause the install to continue if it would normally refuse to continue
due to an existing install.

* Update checksums.

* Address feedback from @prologic.

4 files changed, 104 insertions, 22 deletions

diff --git a/packaging/installer/kickstart-static64.sh b/packaging/installer/kickstart-static64.sh
index 13cba51470..790986bf92 100755
--- a/packaging/installer/kickstart-static64.sh
+++ b/packaging/installer/kickstart-static64.sh
@@ -4,12 +4,13 @@
 # shellcheck disable=SC1117,SC2039,SC2059,SC2086
 #
 #  Options to run
-#  --dont-wait              do not wait for input
-#  --non-interactive        do not wait for input
-#  --dont-start-it          do not start netdata after install
-#  --stable-channel         Use the stable release channel, rather than the nightly to fetch sources
-#  --disable-telemetry      Opt-out of anonymous telemetry program (DO_NOT_TRACK=1)
-#  --local-files            Use a manually provided tarball for the installation
+#  --dont-wait                do not wait for input
+#  --non-interactive          do not wait for input
+#  --dont-start-it            do not start netdata after install
+#  --stable-channel           Use the stable release channel, rather than the nightly to fetch sources
+#  --disable-telemetry        Opt-out of anonymous telemetry program (DO_NOT_TRACK=1)
+#  --local-files              Use a manually provided tarball for the installation
+#  --allow-duplicate-install  do not bail if we detect a duplicate install
 #
 # Environment options:
 #
@@ -179,6 +180,52 @@ sudo=""
 [ -z "${UID}" ] && UID="$(id -u)"
 [ "${UID}" -ne "0" ] && sudo="sudo"
 
+# ---------------------------------------------------------------------------------------------------------------------
+# look for an existing install and try to update that instead if it exists
+
+ndpath="$(command -v netdata 2>/dev/null)"
+if [ -z "$ndpath" ] && [ -x /opt/netdata/bin/netdata ] ; then
+    ndpath="/opt/netdata/bin/netdata"
+fi
+
+if [ -n "$ndpath" ] ; then
+  ndprefix="$(dirname "$(dirname "${ndpath}")")"
+
+  if [ "${ndprefix}" = /usr ] ; then
+    ndprefix="/"
+  fi
+
+  progress "Found existing install of Netdata under: ${ndprefix}"
+
+  if [ -r "${ndprefix}/etc/netdata/.environment" ] ; then
+    if [ -x "${ndprefix}/usr/libexec/netdata/netdata-updater.sh" ] ; then
+      progress "Attempting to update existing install instead of creating a new one"
+      if run ${sudo} "${ndprefix}/usr/libexec/netdata/netdata-updater.sh" ; then
+        progress "Updated existing install at ${ndpath}"
+        exit 0
+      else
+        fatal "Failed to update existing Netdata install"
+        exit 1
+      fi
+    else
+      if [ -z "${NETDATA_ALLOW_DUPLICATE_INSTALL}" ] ; then
+        fatal "Existing installation detected which cannot be safely updated by this script, refusing to continue."
+        exit 1
+      else
+        progress "User explicitly requested duplicate install, proceeding."
+      fi
+    fi
+  else
+    progress "Existing install appears to be handled manually or through the system package manager."
+    if [ -z "${NETDATA_ALLOW_DUPLICATE_INSTALL}" ] ; then
+      fatal "Existing installation detected which cannot be safely updated by this script, refusing to continue."
+      exit 1
+    else
+      progress "User explicitly requested duplicate install, proceeding."
+    fi
+  fi
+fi
+
 # ----------------------------------------------------------------------------
 if [ "$(uname -m)" != "x86_64" ]; then
   fatal "Static binary versions of netdata are available only for 64bit Intel/AMD CPUs (x86_64), but yours is: $(uname -m)."
@@ -228,6 +275,9 @@ while [ -n "${1}" ]; do
 
     NETDATA_LOCAL_TARBALL_OVERRIDE_CHECKSUM="${1}"
     shift 1
+  elif [ "${1}" = "--allow-duplicate-install" ]; then
+    NETDATA_ALLOW_DUPLICATE_INSTALL=1
+    shift 1
   else
     echo >&2 "Unknown option '${1}' or invalid number of arguments. Please check the README for the available arguments of ${0} and try again"
     exit 1
diff --git a/packaging/installer/kickstart.sh b/packaging/installer/kickstart.sh
index a6779174da..1adfaca754 100755
--- a/packaging/installer/kickstart.sh
+++ b/packaging/installer/kickstart.sh
@@ -14,6 +14,7 @@
 #  --non-interactive          do not prompt for user input
 #  --no-updates               do not install script for daily updates
 #  --local-files              set the full path of the desired tarball to run install with
+#  --allow-duplicate-install  do not bail if we detect a duplicate install
 #
 # Environment options:
 #
@@ -278,21 +279,49 @@ sudo=""
 export PATH="${PATH}:/usr/local/bin:/usr/local/sbin"
 
 # ---------------------------------------------------------------------------------------------------------------------
-# try to update using autoupdater in the first place
-
-updater=""
-[ -x /etc/periodic/daily/netdata-updater ] && updater=/etc/periodic/daily/netdata-updater
-[ -x /etc/cron.daily/netdata-updater ] && updater=/etc/cron.daily/netdata-updater
-if [ -L "${updater}" ]; then
-  # remove old updater (symlink)
-  run ${sudo} rm -f "${updater}"
-  updater=""
+# look for an existing install and try to update that instead if it exists
+
+ndpath="$(command -v netdata 2>/dev/null)"
+if [ -z "$ndpath" ] && [ -x /opt/netdata/bin/netdata ] ; then
+    ndpath="/opt/netdata/bin/netdata"
 fi
-if [ -n "${updater}" ]; then
-  # attempt to run the updater, to respect any compilation settings already in place
-  progress "Re-installing netdata..."
-  run ${sudo} "${updater}" -f || fatal "Failed to forcefully update netdata"
-  exit 0
+
+if [ -n "$ndpath" ] ; then
+  ndprefix="$(dirname "$(dirname "${ndpath}")")"
+
+  if [ "${ndprefix}" = /usr ] ; then
+    ndprefix="/"
+  fi
+
+  progress "Found existing install of Netdata under: ${ndprefix}"
+
+  if [ -r "${ndprefix}/etc/netdata/.environment" ] ; then
+    if [ -x "${ndprefix}/usr/libexec/netdata/netdata-updater.sh" ] ; then
+      progress "Attempting to update existing install instead of creating a new one"
+      if run ${sudo} "${ndprefix}/usr/libexec/netdata/netdata-updater.sh" ; then
+        progress "Updated existing install at ${ndpath}"
+        exit 0
+      else
+        fatal "Failed to update existing Netdata install"
+        exit 1
+      fi
+    else
+      if [ -z "${NETDATA_ALLOW_DUPLICATE_INSTALL}" ] ; then
+        fatal "Existing installation detected which cannot be safely updated by this script, refusing to continue."
+        exit 1
+      else
+        progress "User explicitly requested duplicate install, proceeding."
+      fi
+    fi
+  else
+    progress "Existing install appears to be handled manually or through the system package manager."
+    if [ -z "${NETDATA_ALLOW_DUPLICATE_INSTALL}" ] ; then
+      fatal "Existing installation detected which cannot be safely updated by this script, refusing to continue."
+      exit 1
+    else
+      progress "User explicitly requested duplicate install, proceeding."
+    fi
+  fi
 fi
 
 # ---------------------------------------------------------------------------------------------------------------------
@@ -318,6 +347,9 @@ while [ -n "${1}" ]; do
     RELEASE_CHANNEL="stable"
     NETDATA_INSTALLER_OPTIONS="$NETDATA_INSTALLER_OPTIONS --stable-channel"
     shift 1
+  elif [ "${1}" = "--allow-duplicate-install" ]; then
+    NETDATA_ALLOW_DUPLICATE_INSTALL=1
+    shift 1
   elif [ "${1}" = "--local-files" ]; then
     shift 1
     if [ -z "${1}" ]; then
diff --git a/packaging/installer/methods/kickstart-64.md b/packaging/installer/methods/kickstart-64.md
index 7a9e7ff6eb..f5e146dfc8 100644
--- a/packaging/installer/methods/kickstart-64.md
+++ b/packaging/installer/methods/kickstart-64.md
@@ -77,7 +77,7 @@ To use `md5sum` to verify the intregity of the `kickstart-static64.sh` script yo
 command above, run the following:
 
 ```bash
-[ "ff717737ccc2212a3363dad7fa8bd20d" = "$(curl -Ss https://my-netdata.io/kickstart-static64.sh | md5sum | cut -d ' ' -f 1)" ] && echo "OK, VALID" || echo "FAILED, INVALID"
+[ "f47630f78c0c5e651cb6788301d8e05c" = "$(curl -Ss https://my-netdata.io/kickstart-static64.sh | md5sum | cut -d ' ' -f 1)" ] && echo "OK, VALID" || echo "FAILED, INVALID"
 ```
 
 If the script is valid, this command will return `OK, VALID`.
diff --git a/packaging/installer/methods/kickstart.md b/packaging/installer/methods/kickstart.md
index 5c26b349d8..9519aff8de 100644
--- a/packaging/installer/methods/kickstart.md
+++ b/packaging/installer/methods/kickstart.md
@@ -58,7 +58,7 @@ To use `md5sum` to verify the intregity of the `kickstart.sh` script you will do
 run the following:
 
 ```bash
-[ "2057599f8b11ce56f85aa7f26ce7b15b" = "$(curl -Ss https://my-netdata.io/kickstart.sh | md5sum | cut -d ' ' -f 1)" ] && echo "OK, VALID" || echo "FAILED, INVALID"
+[ "05e3a23be90de1c2c62b2dbd8a3fb682" = "$(curl -Ss https://my-netdata.io/kickstart.sh | md5sum | cut -d ' ' -f 1)" ] && echo "OK, VALID" || echo "FAILED, INVALID"
 ```
 
 If the script is valid, this command will return `OK, VALID`.