Cannot insert data to TDengine server that started within Docker

Currently I'm using the command docker run -p 6030-6042:6030-6042/tcp -p 6030-6040:6030-6040/udp --name taosd tdengine/tdengine to start a TDengine server, and then connect it with taos shell in another container with docker run --rm -it tdengine/tdengine taos -h <host ip>. It connects ok, but when inserting data into a table, it causes error:

Welcome to the TDengine shell from Linux, Client Version:2.0.22.0
Copyright (c) 2020 by TAOS Data, Inc. All rights reserved.

taos> create database if not exists test;
Query OK, 0 of 0 row(s) in database (0.000638s)

taos> use test;
Database changed.

taos> create table if not exists tb1 (ts timestamp, n int);
Query OK, 0 of 0 row(s) in database (0.000880s)

taos> insert into tb1 values (now, 1);

DB error: Unable to resolve FQDN (0.090774s)

Solution

TDengine connecting is based on FQDN(hostname if it familiar to you) - which requires DNS resolution for the server end point).

In your case, first set the hostname in start: docker run --hostname taosd ..., and then echo <your ip> taosd >> /etc/hosts in your shell located container or host. then you can connect it with taos -h taosd (here we use taosd as the TDengine server container hostname, all the connections should use hostname to resolve the real ip.)

Steps:

start TDengine server:

docker run --rm --hostname taosd \
  -p 6030-6042:6030-6042/tcp -p 6030-6040:6030-6040/udp \
  --name taosd tdengine/tdengine

start another container as client:
```
docker run --rm -it --add-host taosd:<your ip> tdengine/tdengine taos -h taosd
```
--add-host will add an dns resolvation line in /etc/hosts.

<your ip> you could use the external IP or get the container ip by docker inspect taosd |jq '.[0].NetworkSettings.Networks[].IPAddress' -r.

now insert data with your sql:

create database if not exists test;
use test;
create table if not exists tb1 (ts timestamp, n int);
insert into tb1 values (now, 1);

All done.