get_marathon_log.txt

APP_NAME=foobar
TASK_INDEX=0
LOG_TYPE=stderr # or stdout
MARATHON_HOST="marathon.host.local"
SCHEME=https

MARATHON_TASK_URI="$SCHEME://$MARATHON_HOST/v2/apps/$APP_NAME?embed=app.tasks"
app_info=$(curl "$MARATHON_TASK_URI")

app_task=$(echo ${app_info} | jq -r ".app.tasks[$TASK_INDEX]")
app_task_id=$(echo ${app_task} | jq -r '.id')
app_task_slave_host=$(echo ${app_task} | jq -r '.host')

full_slave_status=$(curl -s $SCHEME://${app_task_slave_host}:5051/state)
app_log_dir=$(echo ${full_slave_status} | jq -r '.frameworks[0].executors[].directory' | grep "${app_task_id}")

path_param="${app_log_dir}/${LOG_TYPE}"
encoded_path=${path_param//\//%2F}

echo
echo "================= ${LOG_TYPE}  ================="
echo "=================LOG BELOW================="

curl $SCHEME://${app_task_slave_host}:5051/files/download?path=${encoded_path}
echo "==================END LOG=================="