Docker deploys Kafka consumer Failed to construct kafka consumer

Docker deploys java project (Kafka consumer) and reports an error, error message:

Failed to construct kafka consumer

and

No resolvable bootstrap urls given in bootstrap.servers

, there will be a warning message in the middle:

Removing server cdh1.tw9.com:9092 from bootstrap.servers as DNSresolution failed for cdh1.tw9.com

Because the idea startup or the jar package startup project uses the local /etc/hostsconfiguration analysis (if this is not enough for you to play chicken) there will be no error message; but when using docker deployment, there is no configuration
inside the container , so dns resolution /etc/hostsDomain name address will report an error

Solution: Modify the /etc/hosts configuration in the container or share the host /etc/hosts data

solution:

One: Directly enter the container to modify /etc/hosts. After restarting the container, the added content will be lost.

Two: Modify directly when making the image. This method requires you to be the root user, and /etc/hoststhe file does not have permissions for ordinary users. So you have to install sudo in the container, which increases the image size and is not recommended.

Three: When using docker run to run a new container, add the domain name and IP information to the container’s /etc/hosts file through the parameter –add-host.
docker run --add-host=cdh1.tw9.com:192.168.9.1 --name server -d service-image

Four: Use docker-compose and configure docker-compose.ymlparameters in the file extra_hosts. For example:

extra_hosts:
- "somehost:162.242.195.82"
- "otherhost:50.31.209.229"

Enter the container and view /etc/hosts to see the corresponding configuration;

Five: Shared hosting /etc/hosts:
The container "shares" the hosts file of the host (the ultimate solution)

Reference:
How to modify the hosts file in the docker container
Docker Compose configuration file details
the container's "shared" host's hosts file (ultimate solution)