Merge pull request #3 from m3dev/doc/readme

[Doc] Add install and usage sections to README

Author: maronuu

README.md

@@ -2,6 +2,110 @@
 
 Kannon is a wrapper for the [gokart](https://github.com/m3dev/gokart) library that allows gokart tasks to be easily executed in a distributed and parallel manner on multiple [kubernetes](https://kubernetes.io/) jobs.
 
+# Install
+Kannon can be installed via `pip`.
+
+```bash
+pip install kannon
+```
+
+# Usage
+It is required for users to prepare following two scripts and copy them into a docker container:
+- A script to start task pipeline on master job.
+- A script for child jobs to run assigned tasks.
+
+Easy and self-contained quick starter will be available soon!
+
+## A script to run job on master job
+Required to:
+- Import module where `gokart.TaskOnKart` and `kannon.TaskOnBullet` classes are defined.
+- Load luigi and k8s configs.
+- Create a task instance.
+- Run `Kannon.build`.
+
+```python
+""" This script runs on master job. """
+import logging
+
+import gokart
+import luigi
+from kubernetes import config, client
+import fire
+
+# TODO: Import task definition here!
+import example_tasks
+from kannon import Kannon
+
+logging.basicConfig(level=logging.INFO)
+
+
+def main(
+    container_name: str,
+    image_name: str,
+):
+    # TODO: Load luigi config here!
+    luigi.configuration.LuigiConfigParser.add_config_path("./conf/base.ini")
+
+    # TODO: Load kube config here!
+    config.load_incluster_config()
+    v1 = client.BatchV1Api()
+    # TODO: Create task instance here!
+    task_root = [CREATE TASK INSTANCE HERE]
+    
+    # TODO: Run Kannon.build!
+    Kannon(
+        api_instance=v1,
+        namespace="mynamespace",
+        image_name=image_name,
+        container_name=container_name,
+        job_prefix="myjob",
+        path_child_script="./run_child.py",
+        env_to_inherit=["TASK_WORKSPACE_DIRECTORY"],
+        service_account_name="myserviceaccount,
+    ).build(task_root)
+
+
+if __name__ == "__main__":
+    Fire.fire(main)
+```
+
+## A script for child jobs to run assigned tasks
+For now, it is required for users to prepare the following script. In the future release, it will not be required.
+
+Required to:
+- Import module where `gokart.TaskOnKart` and `kannon.TaskOnBullet` classes are defined.
+- Load luigi config.
+- Parse a serialized task instance.
+- Run `gokart.build`.
+
+```python
+""" This script requires to be defined by user. """
+import gokart
+import luigi
+import logging
+
+# TODO: Import task definitions here!
+import example_tasks
+
+import fire
+
+logging.basicConfig(level=logging.INFO)
+
+
+def main(serialized_task: str):
+    # TODO: Load luigi config here!
+    luigi.configuration.LuigiConfigParser.add_config_path("./conf/base.ini")
+    
+    # TODO: Parse a serialized gokart.TaskOnKart here!
+    task: gokart.TaskOnKart = gokart.TaskInstanceParameter().parse(serialized_task)
+    # TODO: Run gokart.build!
+    gokart.build(task)
+
+
+if __name__ == "__main__":
+    fire.Fire(main)
+```
+
 # Thanks
 
 Kannon is a wrapper for gokart. Thanks to gokart and dependent projects!