#!/bin/bash

# v1.0:
# - Initial release of the script
# v1.1 CHANGES:
# - Updated query for installed version to versionstring instead of version
# v1.2 CHANGES:
# - Updated nextcloud release check to actually get latest version from the release-url
# v1.3 CHANGES:
# - Added check for configured apache-user and basepath exist.
# v1.4 CHANGES:
# - added extra logic to deal with unresponsive or empty response from release-url
# v1.5 CHANGES:
# - added enhancement sugestion made by briand on checkmk forum to make the version-compare more granular
# Version 1.6 CHANGES:
# - Restructured and refined variables, also added additional comments per line of code
#
# WARNING: Current logic in the check will report wrong version as upgrade when a release is withdrawn from a/the release-url.

# Current active version of the script
SCRIPT_VERSION=1.6

# Installation:
# This file should be place on a/the nextcloud host in /usr/lib/check_mk_agent/local
#
# (optional) if you want the check to run on a different schedule (like once per hour) put it in a subdirectory of above path
# named to the number of seconds of the interval wanted, so 3600/ for once an hour, 86400 for once per day.
#
# Also do not forget to make this file executable with chmod +x /usr/lib/check_mk_agent/local/nextcloud-updates.sh

# (c) Michael Honkoop <mhonkoop@comsolve.nl>

# License: GNU General Public License v2

######################
# Configurable Parameters
######################

# url to check releases against
RELEASEURL="https://download.nextcloud.com/server/releases/"

#basepath of Nextcloud's occ executable
BASEPATH="/var/www/nextcloud"

# set the correct user for running the commands (either apache or www-data, this depends on your Linux-Distribution)
APACHEUSER="www-data"

# Service name
SERVICE="NextCloud"

# Set how exact the version-comparison should be - enhancement suggested by briand at checkmk forum
#
# how many “.”-separated fields to compare:
#  3 → XX.YY.ZZ  (full)
#  2 → XX.YY     (major+minor)
#  1 → XX        (major only)
VERSION_FIELDS=2

# Service name
SERVICE="NextCloud"

######################
# The code below should not be changed, unless you know EXACTLY what you are doing.
# All configureable parameters are above this section.
######################

# check if jq package is present on the system
if ! command -v curl >/dev/null 2>&1; then
    echo "2 \"$SERVICE\" - $SERVICE localcheck requires jq package to be installed"
    echo "2 \"$SERVICE Apps\" - $SERVICE Apps  localcheck requires jq package to be installed"
    exit 0
fi

# check if configured apache user exists
if ! id -u "$APACHEUSER" >/dev/null 2>&1; then
    echo "2 \"$SERVICE\" - $SERVICE localcheck webserver user does not exist, check configuration!"
    echo "2 \"$SERVICE Apps\" - $SERVICE Apps localcheck webserver user does not exist, check configuration!"
    exit 0
fi

# check if configured basepath exists
if [ ! -d "$BASEPATH" ]; then
    echo "2 \"$SERVICE\" - $SERVICE localcheck could not find configured basepath, check configuration!"
    echo "2 \"$SERVICE Apps\" - $SERVICE Apps localcheck could not find configured basepath, check configuration!"
    exit 0
fi

# Get current installed Nextcloud version-information
# in v29.x.x version gives more detail, which is not given by the check on installed version, so switched to versionstring instead.

NCINSTALLED=$(sudo -u "$APACHEUSER" php "$BASEPATH"/occ status --output=json | jq -r '.versionstring' | cut -d. -f1-"$VERSION_FIELDS")

# Get latest avaiable (core) version information
# In v29.x.x this has changed outputs <name-of-instance> <version>,

NCAVAILABLE=$(curl -s --connect-timeout 5 --fail-with-body "$RELEASEURL" | sed -e 's/<[^>]*>//g' | grep -o "^nextcloud.*.zip" | tail -n1 | cut -d'-' -f 2 | sed 's/.\{4\}$//' | cut -d. -f1-"$VERSION_FIELDS")

# if the check on the release-url is not returning a version - report status
if [ -z "$NCAVAILABLE" ]; then
    echo "1 \"$SERVICE\" - No data received from release-URL, can not determine latest release-version for $SERVICE Core"

# compare resuts of installed and available version and report update available if they differ
elif [ "$NCINSTALLED" != "$NCAVAILABLE" ]; then
   echo "1 \"$SERVICE\" - A new $SERVICE Core version ($NCAVAILABLE) is available, running Core version is: $NCINSTALLED please upgrade"
else
    sudo -u "$APACHEUSER" php "$BASEPATH"/occ status -e
    if [ $? -eq 0 ]; then
        echo "0 \"$SERVICE\" - $SERVICE all up to date"
    elif [ $? -eq 1 ]; then
        echo "1 \"$SERVICE\" - $SERVICE maintenance-mode is enabled"
    elif [ $? -eq 2 ]; then
        echo "2 \"$SERVICE\" - $SERVICE Core needs updating"
    fi
fi

APPRESULT=$(sudo -u "$APACHEUSER" php "$BASEPATH"/occ app:update --showonly)
if [[ "$APPRESULT" == *"All apps are up-to-date"* ]]; then
    echo "0 \"$SERVICE Apps\" - $SERVICE Apps all up to date"
    exit 0
else
    UPDATECOUNT=$(echo "$APPRESULT" | wc -l)
    echo "1 \"$SERVICE Apps\" - $UPDATECOUNT $SERVICE Apps requires updates"
    exit 0
fi