Access local database or API

By default, docker-hosted instances use a bridge network, which does not support access to services on the docker-host via 127.0.0.1 or localhost from inside of the docker.

Here we take PostgreSQL as an example and show you how to access local API or database in different operating systems (OS) for docker-hosted Lowcoder.

Preparation

Assume that a Postgres service is ready on your local host with port 5432.

On Linux, you can check if Postgres runs locally with the command pgrep -u postgres -fa -- -D

How to access a local database or API from Lowcoder which runs inside the Docker

Linux

1. Enter ifconfig docker0 in the terminal, and verify the IP configuration of Docker's virtual bridge (VB).

   Having set up Docker, the OS would automatically create docker0 using the IP address 172.17.0.1 (by default), through which the Docker service communicates with the host.

2. Enter the same IP address into Lowcoder to configure the Postgres data source (172.17.0.1 in this example, but use the actual IP address displayed on your terminal in the real case).

On some OS (such as Ubuntu), port access might be blocked by the firewall. To solve that, configure in the following steps:

1. Stop the firewall from blocking access from docker0 by typing in the terminal:\ iptables -A INPUT -p tcp -i docker0 --dport YOUR_DB_PORT -j ACCEPT Note: In this caseHere we use Postgres port 5432 for YOUR_DB_PORT, and you should replace it with your own.

2. Save the firewall configuration by typing in the terminal: iptables-save > /etc/iptables.up.rules

Windows & Mac

On Windows and macOS, Docker does not create the virtual bridge docker0. Then the following host name is helpful to resolve the host IP:

host.docker.internal

On Windows and Mac:

Access a Database on your local network from Lowcoder which runs in Docker

Access an API on your local network from Lowcoder which runs in Docker