The motivation and goal LGTM, but the API changes look very simple and hard to use. Do we have to implement all these interfaces for an admin extension? If yes, could you show an example in the proposal as a guidance?
For example, if I just want to implement a simple command: ```bash ./bin/pulsar-admin kafka create-topic <my-topic> --partitions <num-partitions> ``` How should I implement these interfaces? Thanks, Yunze > 2022年8月18日 16:23，Enrico Olivelli <eolive...@gmail.com> 写道： > > Hello, > I have drafted a PIP around this proposal. > > PIP link: https://github.com/apache/pulsar/issues/17155 > > I am preparing an official PR, I already have a working prototype. > > Copy of the contents of the GH issue is attached for discussion here > on the Mailing list. > > Motivation > > There are many projects that are in the Pulsar ecosystem like Protocol > Handlers (Kafka, MQTT, RabbitMQ) and libraries (JMS…) that need > additional tools for operating Pulsar following specific conventions > adopted by each project and to handle custom domain objects (like JMS > queues, Kafka Consumer Groups...). > > Some examples: > > Kafka: tools for inspecting internal systems, SchemaRegistry, > Transaction Manager, Consumers Groups > JMS: tools to handling Subscriptions and Selectors > RabbitMQ: tools to handle Pulsar topics and subscription following the > convention > > This is very important as it is hard to follow the conventions of each > project using pulsar-admin and the administrator may inadvertently > break the system. > > This feature will enhance the UX of the Pulsar Admin CLI tools for the > benefit of the whole ecosystem and users. > > Goal > > As we do for many other components in Pulsar, we need a way to enhance > the CLI tools, pulsar-admin and pulsar-shell, with additional commands > that are specific to the additional features. > > The proposal here is to add an extension mechanism to the pulsar-admin > (and so pulsar-shell) tool. > Following the usual conventions for extensions the extension will be > bundled in a .nar file that may contain additional third party > libraries. > > The extension will be able to provide new top level commands > > pulsar-admin my-command-group my-command arguments… > > The extension will be able to access the PulsarAdmin API provided by > the environment. > > The extension must not depend directly on the JCommander library but > we will provide an API to declare the parameters and the other > metadata necessary to document and execute the command. > This is very important because during the lifecycle of Pulsar the > project may decide to upgrade JCommander to an incompatible version or > to drop the dependency at all. > > API Changes > > We will introduce a new Maven module pulsar-tools-api that contains > the public API that can be used by implementations of the custom > commands. > > The implementation will be bundled in a .nar file with a descriptor > with the following fields: > > factoryClass: xxxxx.CommandFactory > name: extension-name > description: Description... > > There are the new classes: > > /** > Access to the environment > */ > public interface CommandExecutionContext { > PulsarAdmin getPulsarAdmin(); > Properties getConfiguration(); > } > > > /** > * Custom command implementation > */ > public interface CustomCommand { > String name(); > String description(); > List<ParameterDescriptor> parameters(); > boolean execute(Map<String, Object> parameters, > CommandExecutionContext context) throws Exception; > } > > /** > * A group of commands. > */ > public interface CustomCommandGroup { > String name(); > String description(); > List<CustomCommand> commands(CommandExecutionContext context); > } > > /** > * Main entry point of the extension > */ > public interface CustomCommandFactory { > > /** > * Generate the available command groups. > */ > List<CustomCommandGroup> commandGroups(CommandExecutionContext context); > } > > @Builder > @Getter > public final class ParameterDescriptor { > @Builder.Default > private String name = ""; > @Builder.Default > private String description = ""; > private ParameterType type = ParameterType.STRING; > private boolean required = false; > }
