How to add my own custom kafka commands into this?
Opened this issue · 4 comments
Hi Shawn- First of all great work!. I'm working on adding extra kafka commands into this shell. Any pointers? I was able to add to add custom command into the menu but options execution throws error. I thought to reach out to you for the pointers so that I can add some commands to this and take it forward.
Thanks
Hi there, thank you!
The steps look like this:
- Add the new command and its options to the
completer.json
file in thekafkashell/data
directory. - Implement new logic in the
kafkashell/executor.py
class. This class takes the user input when it is submitted. It then matches specific methods based on the input and executes them.
For example, take the kafka-topics
command. If a user enters kafka-topics --list
in kafka-shell
, it will be sent to the executor class. It will match this block on line 59:
elif command.startswith(valid_command_prefixes):
self.execute_valid_command(command)
Then, it will match the following block on line 63:
if command.startswith(constants.COMMAND_KAFKA_TOPICS):
final_command = self.handle_kafka_topics_command(command)
We then handle the kafka topics command. This is where we automatically add flags such as --bootstrap-servers
. This starts on line 166.
def handle_kafka_topics_command(self, command):
command += self.handle_bootstrap_or_zookeeper_flag(command)
command += self.handle_admin_client_settings(command)
return command
Lastly, we end up with a final_command
that gets executed by os.system(final_command)
on line 126.
If you want to implement non-Kafka based commands, look at the exit
or save
methods in the executor for examples.
I hope that helps!
Thanks for the info Shawn. I have couple of questions.
- How do you discover kafka install location? Is it via port#?
- Does this work on a secure environment?
- I notice a decorator @staticmethod being used. Where is that coming from?
Happy to help, @xargs-Pratix!
-
It depends on how you've installed kafka. Most kafka installations run on port
9092
. If you've installed it on a local machine and have started a kafka cluster, yourbootstrap.servers
are most likelylocalhost:9092
. -
Yes, this can work in a secure environment. If you're talking about a secure kafka cluster, you can pass client/admin config files with the tool (defined in the kafka-shell config file).
-
It's built into python, see this post more information.
Hope that helps!