I have my Rsp Pi using node red to process some sensors data, then I am saving the data into influxDb. Now I'd like to be able to access my database (influxdb) from my laptop (running with linux). Someone has ideas on how to do it ? Useful ressources ?
You need to understand a little about the network(s) you are using. This has an impact on what you might need to do (if anything) to enable direct access to InfluxDB on the Pi from a laptop.
If they are both on the same network, then you just need to know the IP address of the Pi. You might also need to adjust the IPTABLES firewall on the Pi to allow an incoming connection on the port that InfluxDB uses (can't remember that off the top of my head, it is in the docs).
If the laptop needs access when on a different network to the Pi (e.g. over the Internet), that is a completely different matter. More complex and needing a lot more security.
The other question is whether you actually need to access the database or whether you could use Node-RED to present a web UI of the data?