{% import_yaml 'salt/minion.defaults.yaml' as SALT_MINION_DEFAULTS -%}

#!/bin/bash
#
# Copyright 2014-2022 Security Onion Solutions, LLC
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

# this script checks the time the file /opt/so/log/salt/state-apply-test was last modified and restarts the salt-minion service if it is outside a threshold date/time
# the file is modified via file.touch using a scheduled job healthcheck.salt-minion.state-apply-test that runs a state.apply. 
# by default the file should be updated every 5-8 minutes. 
# this allows us to test that the minion is able apply states and communicate with the master
# if the file is unable to be touched via the state.apply, then we assume there is a possibilty that the minion is hung (though it could be possible the master is down as well)
# we then stop the service, pkill salt-minion, the start the salt-minion service back up

. /usr/sbin/so-common

QUIET=false
UPTIME_REQ=1800 #in seconds, how long the box has to be up before considering restarting salt-minion due to /opt/so/log/salt/state-apply-test not being touched
CURRENT_TIME=$(date +%s)
SYSTEM_START_TIME=$(date -d "$(</proc/uptime awk '{print $1}') seconds ago" +%s)
LAST_HIGHSTATE_END=$([ -e "/opt/so/log/salt/lasthighstate" ] && date -r /opt/so/log/salt/lasthighstate +%s || echo 0)
LAST_HEALTHCHECK_STATE_APPLY=$([ -e "/opt/so/log/salt/state-apply-test" ] && date -r /opt/so/log/salt/state-apply-test +%s || echo 0)
# SETTING THRESHOLD TO ANYTHING UNDER 600 seconds may cause a lot of salt-minion restarts since the job to touch the file occurs every 5-8 minutes by default
THRESHOLD={{SALT_MINION_DEFAULTS.salt.minion.check_threshold}} #within how many seconds the file /opt/so/log/salt/state-apply-test must have been touched/modified before the salt minion is restarted
THRESHOLD_DATE=$((LAST_HEALTHCHECK_STATE_APPLY+THRESHOLD))

logCmd() {
  cmd=$1
  info "Executing command: $cmd"
  $cmd >> "/opt/so/log/salt/so-salt-minion-check"
}

log() {
    msg=$1
    level=${2:-I}
    now=$(TZ=GMT date +"%Y-%m-%dT%H:%M:%SZ")
    if ! $QUIET; then
      echo $msg
    fi
    echo -e "$now | $level | $msg" >> "/opt/so/log/salt/so-salt-minion-check" 2>&1
}

error() {
    log "$1" "E"
}

info() {
    log "$1" "I"
}

usage()
{
cat <<EOF

Check health of salt-minion and restart it if needed
  Options:
  -h                This message
  -q                Don't output to terminal

EOF
}

while getopts ":q" opt; do
  case "$opt" in
    q )
       QUIET=true
      ;;
    * ) usage
        exit 0
      ;;
  esac
done

log "running so-salt-minion-check"

if [ $CURRENT_TIME -ge $((SYSTEM_START_TIME+$UPTIME_REQ))  ]; then
  if [ $THRESHOLD_DATE -le $CURRENT_TIME ]; then
    log "salt-minion is unable to apply states" E
    log "/opt/so/log/salt/healthcheck-state-apply not touched by required date: `date -d @$THRESHOLD_DATE`, last touched: `date -d @$LAST_HEALTHCHECK_STATE_APPLY`" I
    log "last highstate completed at `date -d @$LAST_HIGHSTATE_END`" I
    log "checking if any jobs are running" I
    logCmd "salt-call --local saltutil.running" I
    log "ensure salt.minion-state-apply-test is enabled" I
    logCmd "salt-call state.enable salt.minion-state-apply-test" I
    log "ensure highstate is enabled" I
    logCmd "salt-call state.enable highstate" I
    log "killing all salt-minion processes" I
    logCmd "pkill -9 -ef /usr/bin/salt-minion" I
    log "starting salt-minion service" I
    logCmd "systemctl start salt-minion" I
  else
    log "/opt/so/log/salt/healthcheck-state-apply last touched: `date -d @$LAST_HEALTHCHECK_STATE_APPLY` must be touched by `date -d @$THRESHOLD_DATE` to avoid salt-minion restart" I
  fi
else
  log "system uptime only $((CURRENT_TIME-SYSTEM_START_TIME)) seconds does not meet $UPTIME_REQ second requirement." I
fi