zoo-template-common

Shared reusable classes for service templates used in the ZOO-Project CWL runner ecosystem.

This repository centralizes commonly used logic like execution handlers and STAC I/O utilities to avoid duplication and simplify maintenance across multiple service templates.

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Included Modules

File	Description
common_execution_handler.py	Defines a base ExecutionHandler class with standard hook methods like pre_execution_hook, post_execution_hook, handle_outputs, etc.
common_stac_io.py	Implements CustomStacIO using boto3 to support reading/writing STAC catalogs from/to S3.

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How to Use in a Service Template

1. Import the Common Execution Handler

from zoo_template_common.common_execution_handler import ExecutionHandler

class MyHandler(ExecutionHandler):
    def handle_outputs(self, log, output, usage_report, tool_logs):
        self.results = {"url": output["result_path"]}

You can override only the hooks you need:

def get_pod_env_vars(self, **kwargs):
    return {"A": "1", "B": "2"}

2. Use the Custom STAC I/O Handler for S3

from zoo_template_common.common_stac_io import CustomStacIO
from pystac.stac_io import StacIO

StacIO.set_default(CustomStacIO)

Why Use This?

• Avoids duplicating handler and I/O logic across templates

• Centralizes updates and bug fixes

• Promotes extensibility using clean class inheritance

• Easily shareable across multiple ZOO service templates

Repositories Using This

• zoo-service-template
• eoepca-proc-service-template
• zoo-argo-wf-proc-service-template
• eoepca-proc-service-template-wes

Local Development & Installation

Add it to PYTHONPATH in your service.py:

import sys, os
sys.path.append("/path/to/zoo-template-common")