Valheim Server Discord Alerts

logwatcher.sh

#!/bin/bash

##########################
# Change these variables #
##########################
FILE="/path/to/console.log"
WEBHOOK_URL="CHANGEME"
STEAMKEY="CHANGEME"
##########################

### script logic ###
# array to store steam ids and map to player names
declare -A SteamID
# initialize global variables
lastSteamID=0
havePlayerName=0 

# begin watching the log file and check each new line
tail -Fn0 $FILE | \
while read -r line ; do
    # check for the matching lines we want to look into further
        if grep -iq "Closing socket\|Got handshake from client\|Got character ZDOID from" <<< "$line"
        then
            # tokenize the line sp;it by colons so easier to process
            IFS=':' tokens=( $line )
            # we're only interested in the text of the log entry
            entry=$(echo "${tokens[3]}" | xargs)
            # get rid of windows carriage return
            entry="$(echo $entry | sed 's/\r//g')"
            if grep -iq "Got handshake from client" <<< "$entry"
            then
                # grab everything in the entry past the matching text and mark that we have a recent steam id
                lastSteamID=$(sed -n -e 's/^.*Got handshake from client //p' <<< "$entry")
                haveSteamID=1
            elif grep -iq "Got character ZDOID from" <<< "$entry"
            then
                # grab everything in the entry past the matching text and mark that we have a recent player name
                playerName=$(sed -n -e 's/^.*Got character ZDOID from //p' <<< "$entry")
                havePlayerName=1
                # add the name and id to the array for recall later
                SteamID[$lastSteamID]=$playerName
                # if we have both a recent name and recent steam id go ahead and assume we have a new client that connected and send alert
                if [[ havePlayerName -eq 1 && haveSteamID -eq 1 ]]
                then
                    # grab the steam id profile url and name
                    response=$(curl -Gs -d "steamids=${lastSteamID}" -d "key=${STEAMKEY}" https://api.steampowered.com/ISteamUser/GetPlayerSummaries/v2/)
                    profile=$(jq '.response.players[0].profileurl' <<< $response | tr -d "\"")
                    personaname=$(jq '.response.players[0].personaname' <<< $response | tr -d "\"")
                    # output to terminal
                    echo "Player ${playerName} (probably ${lastSteamID}) has joined the server - Steam profile ${personaname} (${profile})"
                    # send to Discord
                    curl -X POST --data "{\"content\": \"Player ${playerName} (probably ${lastSteamID}) has joined the server - Steam profile ${personaname} (${profile})\"}" --header "Content-Type:application/json" "$WEBHOOK_URL"
                    # reset variables so we're not sending alerts without it being a new connection
                    havePlayerName=0
                    haveSteamID=0
                fi
            elif grep -iq "Closing socket" <<< "$entry"
            then
                # grab everything in the entry past the matching text
                socket=$(sed -n -e 's/^.*Closing socket //p' <<< "$entry")
                # check that it's an actual socket closing
                if [ "$socket" != "0" ]
                then
                    # output to terminal
                    echo "SteamID ${socket} left the server (was probably ${SteamID[$socket]})"
                    # send to Discord
                    curl -X POST --data "{\"content\": \"SteamID ${socket} left the server (was probably ${SteamID[$socket]})\"}" --header "Content-Type:application/json" "$WEBHOOK_URL"
                fi
            else
                # this should never happen but is included for failover
                echo "unhandled entry:" "$entry"
            fi
        fi
done