Networking
The docker-compose instruction creates an internal network for the containers to communicate in, the ports get exposed to the PI's IP address when you want to connect from outside. It also creates a "DNS" the name being the container name. So it is important to note that when one container talks to another they talk by name. All the containers names are lowercase like nodered, influxdb...
An easy way to find out your IP is by typing ip address in the terminal and look next to eth0 or wlan0 for your IP. It is highly recommended that you set a static IP for your PI or at least reserve an IP on your router so that you know it
Check the docker-compose.yml to see which ports have been used
You want to connect your nodered to your mqtt server.
In nodered drop an mqtt node, when you need to specify the address type mosquitto
You want to connect to your influxdb from grafana. You are in the Docker network and you need to use the name of the Container. The address you specify in the grafana is http://influxdb:8086
You want to connect to the web interface of grafana from your laptop. Now you are outside the container environment you type PI's IP eg 192.168.n.m:3000