check_digitalocean_config_nagios.sh

#!/bin/bash

set -euo pipefail
err() {
        echo $1 >>/dev/stderr
        rm -f $TMP_SNAPSHOT_FILE
        exit 3
}
trap "err 'Error while running monitoring commands'" ERR

CONFIG_SNAPSHOT_FILE=/tmp/check_digitalocean_config_snapshot.json
TMP_SNAPSHOT_FILE=`tempfile`
API="https://api.digitalocean.com/v2"
TOKEN=""
ID=""
ACKNOWLEDGE=0

# thanks to https://stackoverflow.com/questions/192249/how-do-i-parse-command-line-arguments-in-bash/29754866
while [[ $# -gt 0 ]]
do
        key="$1"
        case $key in
                -t|--token)
                        TOKEN="$2"
                        shift # past argument
                        shift # past value
                        ;;
                -u|--url)
                        API="$2"
                        shift # past argument
                        shift # past value
                        ;;
                -i|--id)
                        ID="$2"
                        shift # past argument
                        shift # past value
                        ;;
                --acknowledge)
                        ACKNOWLEDGE=1
                        shift
                        ;;
                *)
                        err "Unknown command option - run without parameters for usage"
                        ;;
        esac
done
if [ -z "$TOKEN" -o -z "$ID" ]; then
        echo "Usage: $0 -t|--token <DO token> -i|--id <unique ID for this DO token> [ --acknowledge ] [ -u|--url <DO URL up including /v2> ]" >>/dev/stderr
        exit 3
fi
CONFIG_SNAPSHOT_FILE="$CONFIG_SNAPSHOT_FILE.$ID"

JQ=`which jq`
if [ -z "$JQ" ]; then
        echo "Could not find 'jq' for JSON parsing"
        exit 2
fi
CURL=`which curl`
if [ -z "$CURL" ]; then
        echo "Could not find 'curl'"
        exit 2
fi
DIFF=`which diff`
if [ -z "$DIFF" ]; then
        echo "Could not find 'diff'"
        exit 2
fi

diff() {
        $DIFF --suppress-common-lines --ignore-space-change --ignore-blank-lines $1 $2
}

curl() {
        $CURL --connect-timeout 20 --silent --show-error --header 'Content-Type: application/json' --header "Authorization: Bearer $TOKEN" $API$1 | jq "$2"
}

(
for i in /domains /databases /certificates /droplets /load_balancers /account/keys /images /firewalls /floating_ips; do
        curl $i '. | del(.links?) | del(.meta?)'
done
) | jq --slurp add >$TMP_SNAPSHOT_FILE

if [ ! -w $CONFIG_SNAPSHOT_FILE ]; then
        cp $TMP_SNAPSHOT_FILE $CONFIG_SNAPSHOT_FILE || err "Failed to copy new to old snapshot!"
        echo "Initialising with new state"
        exit 3
fi
set +e
trap - ERR
diff $CONFIG_SNAPSHOT_FILE $TMP_SNAPSHOT_FILE
DIFFRESULT=$?
if [ $DIFFRESULT -eq 2 ]; then
        err 'Failed to run diff'
fi
if [ $DIFFRESULT -eq 1 ]; then
        if [ $OVERWRITE -eq 1 ]; then
                cp $TMP_SNAPSHOT_FILE $CONFIG_SNAPSHOT_FILE
                echo "Infrastructure changes acknowledged!"
                rm -f $TMP_SNAPSHOT_FILE
                exit 1
        fi
        echo "Infrastructure changes detected! Run with --acknowledge to acknowledge and update the stored config!"
        rm -f $TMP_SNAPSHOT_FILE
        # exit code 2 = critical
        exit 2
fi
rm -f $TMP_SNAPSHOT_FILE
exit 0