Helper script to pretty print and filter docker JSON logs output

logs.sh

logs_help () {
   echo "Usage:"
   echo "logs <container name> <jq expression>"
 }

CONTAINER=$1
FILTER="$2"

if [ ! $# -eq 1 ]; then
  logs_help
else
  # First argument passed to jq is to filter out log lines that are not valid JSON
  docker-compose logs -f $1 --no-log-prefix 2>&1 | jq -R "fromjson? | $FILTER"
fi

Example to print everything:

logs api .

Example to get only the msg from the logs:

logs api {msg}

Example to get messages containing text:

logs api 'select(.msg | contains("THING"))'