https://github.com/stac-utils/stac-task
Provides a class interface for running custom algorithms on STAC ItemCollections
https://github.com/stac-utils/stac-task
Last synced: 4 days ago
JSON representation
Provides a class interface for running custom algorithms on STAC ItemCollections
- Host: GitHub
- URL: https://github.com/stac-utils/stac-task
- Owner: stac-utils
- License: apache-2.0
- Created: 2022-08-12T02:20:38.000Z (almost 3 years ago)
- Default Branch: main
- Last Pushed: 2024-04-22T13:03:52.000Z (about 1 year ago)
- Last Synced: 2024-04-22T13:44:17.122Z (about 1 year ago)
- Language: Python
- Size: 952 KB
- Stars: 18
- Watchers: 9
- Forks: 4
- Open Issues: 12
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- License: LICENSE
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README
# STAC Task (stac-task)
[](https://github.com/stac-utils/stac-task/actions/workflows/continuous-integration.yml)
[](https://badge.fury.io/py/stac-task)
[](https://stac-task.readthedocs.io/en/latest/?badge=latest)
[](https://codecov.io/gh/stac-utils/stac-task)
[](https://opensource.org/licenses/Apache-2.0)
- [Quickstart for Creating New Tasks](#quickstart-for-creating-new-tasks)
- [Task Input](#task-input)
- [ProcessDefinition Object](#processdefinition-object)
- [UploadOptions Object](#uploadoptions-object)
- [path\_template](#path_template)
- [collections](#collections)
- [tasks](#tasks)
- [TaskConfig Object](#taskconfig-object)
- [workflow_options](#workflow_options)
- [Full ProcessDefinition Example](#full-processdefinition-example)
- [Migration](#migration)
- [0.4.x -\> 0.5.x](#04x---05x)
- [0.5.x -\> 0.6.0](#05x---060)
- [Development](#development)
- [Contributing](#contributing)
This Python library consists of the Task class, which is used to create custom tasks
based on a "STAC In, STAC Out" approach. The Task class acts as wrapper around custom
code and provides several convenience methods for modifying STAC Items, creating derived
Items, and providing a CLI.
This library is based on a [branch of cirrus-lib](https://github.com/cirrus-geo/cirrus-lib/tree/features/task-class)
except aims to be more generic.
## Quickstart for Creating New Tasks
```python
from typing import Any
from stactask import Task, DownloadConfig
class MyTask(Task):
name = "my-task"
description = "this task does it all"
def validate(self, payload: dict[str, Any]) -> bool:
return len(self.items) == 1
def process(self, **kwargs: Any) -> list[dict[str, Any]]:
item = self.items[0]
# download a datafile
item = self.download_item_assets(
item,
config=DownloadConfig(include=['data'])
)
# operate on the local file to create a new asset
item = self.upload_item_assets_to_s3(item)
# this task returns a single item
return [item.to_dict(include_self_link=True, transform_hrefs=False)]
```
## Task Input
Task input is often referred to as a 'payload'.
| Field Name | Type | Description |
| ---------- | ------------------------- | --------------------------------------------------- |
| type | string | Must be FeatureCollection |
| features | [Item] | An array of STAC Items |
| process | [`ProcessDefinition`] | An array of `ProcessDefinition` objects. |
| ~~process~~ | ~~`ProcessDefinition`~~ | **DEPRECATED** A `ProcessDefinition` object |
### ProcessDefinition Object
A Task can be provided additional configuration via the 'process' field in the input
payload.
| Field Name | Type | Description |
| ---------------- | ------------------ | ------------------------------------------------------------------------ |
| description | string | Description of the process configuration |
| upload_options | `UploadOptions` | An `UploadOptions` object |
| tasks | Map | Dictionary of task configurations. |
| ~~tasks~~ | ~~[`TaskConfig`]~~ | **DEPRECATED** A list of `TaskConfig` objects. |
| workflow_options | Map | Dictionary of configuration options applied to all tasks in the workflow |
#### UploadOptions Object
Options used when uploading Item assets to a remote server can be specified in a
'upload_options' field in the `ProcessDefinition` object.
| Field Name | Type | Description |
| ------------- | ------------- | --------------------------------------------------------------------------------------- |
| path_template | string | **REQUIRED** A string template for specifying the location of uploaded assets |
| public_assets | [str] | A list of asset keys that should be marked as public when uploaded |
| headers | Map | A set of key, value headers to send when uploading data to s3 |
| collections | Map | A mapping of output collection name to a JSONPath pattern (for matching Items) |
| s3_urls | bool | Controls if the final published URLs should be an s3 (s3://*bucket*/*key*) or https URL |
##### path_template
The 'path_template' string is a way to control the output location of uploaded assets
from a STAC Item using metadata from the Item itself. The template can contain fixed
strings along with variables used for substitution. See [the PySTAC documentation for
`LayoutTemplate`](https://pystac.readthedocs.io/en/stable/api/layout.html#pystac.layout.LayoutTemplate)
for a list of supported template variables and their meaning.
##### collections
The 'collections' dictionary provides a collection ID and JSONPath pattern for matching
against STAC Items. At the end of processing, before the final STAC Items are returned,
the Task class can be used to assign all of the Items to specific collection IDs. For
each Item the JSONPath pattern for all collections will be compared. The first match
will cause the Item's Collection ID to be set to the provided value.
For example:
```json
"collections": {
"landsat-c2l2": "$[?(@.id =~ 'LC08.*')]"
}
```
In this example, the task will set any STAC Items that have an ID beginning with "LC08"
to the `landsat-c2l2` collection.
See [JSONPath Online Evaluator](https://jsonpath.com) to experiment with JSONPath and
[regex101](https://regex101.com) to experiment with regex.
#### tasks
The 'tasks' field is a dictionary with an optional key for each task. If present, it
contains a dictionary that is converted to a set of keywords and passed to the Task's
`process` function. The documentation for each Task will provide the list of available
parameters.
```json
{
"tasks": {
"task-a": {
"param1": "value1"
},
"task-c": {
"param2": "value2"
}
}
}
```
In the example above, a task named `task-a` would have the `param1=value1` passed as a
keyword, while `task-c` would have `param2=value2` passed. If there were a `task-b` to
be run, it would not be passed any keywords.
#### TaskConfig Object
**DEPRECATED** The 'tasks' field _should_ be a dictionary of parameters, with task names
as keys. See [tasks](#tasks) for more information. `TaskConfig` objects are supported
for backwards compatibility.
| Field Name | Type | Description |
| ---------- | ------------- | ----------------------------------------------------------------------------------- |
| name | str | **REQUIRED** Name of the task |
| parameters | Map | Dictionary of keyword parameters that will be passed to the Task `process` function |
#### workflow_options
The 'workflow_options' field is a dictionary of options that apply to all tasks in the
workflow. The 'workflow_options' dictionary is combined with each task's option
dictionary. If a key in the 'workflow_options' dictionary conflicts with a key in a
task's option dictionary, the task option value takes precedence.
### Full ProcessDefinition Example
```json
{
"description": "My process configuration",
"upload_options": {
"path_template": "s3://my-bucket/${collection}/${year}/${month}/${day}/${id}",
"collections": {
"landsat-c2l2": "$[?(@.id =~ 'LC08.*')]"
}
},
"tasks": {
"task-name": {
"param": "value"
}
}
}
```
## Migration
### 0.4.x -> 0.5.x
In 0.5.0, the previous use of fsspec to download Item Assets has been replaced with the
stac-asset library. This has necessitated a change in the parameters that the download
methods accept.
The primary change is that the Task methods `download_item_assets` and
`download_items_assets` (items plural) now accept fewer explicit and implicit (kwargs)
parameters.
Previously, the methods looked like:
```python
def download_item_assets(
self,
item: Item,
path_template: str = "${collection}/${id}",
keep_original_filenames: bool = False,
**kwargs: Any,
) -> Item:
```
but now look like:
```python
def download_item_assets(
self,
item: Item,
path_template: str = "${collection}/${id}",
config: Optional[DownloadConfig] = None,
) -> Item:
```
Similarly, the `asset_io` package methods were previously:
```python
async def download_item_assets(
item: Item,
assets: Optional[list[str]] = None,
save_item: bool = True,
overwrite: bool = False,
path_template: str = "${collection}/${id}",
absolute_path: bool = False,
keep_original_filenames: bool = False,
**kwargs: Any,
) -> Item:
```
and are now:
```python
async def download_item_assets(
item: Item,
path_template: str = "${collection}/${id}",
config: Optional[DownloadConfig] = None,
) -> Item:
```
Additionally, `kwargs` keys were set to pass configuration through to fsspec. The most
common parameter was `requester_pays`, to set the Requester Pays flag in AWS S3
requests.
Many of these parameters can be directly translated into configuration passed in a
`DownloadConfig` object, which is just a wrapper over the `stac_asset.Config` object.
Migration of these various parameters to `DownloadConfig` are as follows:
- `assets`: set `include`
- `requester_pays`: set `s3_requester_pays` = True
- `keep_original_filenames`: set `file_name_strategy` to
`FileNameStrategy.FILE_NAME` if True or `FileNameStrategy.KEY` if False
- `overwrite`: set `overwrite`
- `save_item`: none, Item is always saved
- `absolute_path`: none. To create or retrieve the Asset hrefs as absolute paths, use
either `Item#make_all_asset_hrefs_absolute()` or `Asset#get_absolute_href()`
### 0.5.x -> 0.6.0
Previously, the `validate` method was a _classmethod_, validating the payload argument
passed. This has now been made an instance method, which validates the `self._payload`
copy of the payload, from which the `Task` instance is constructed. This is
behaviorally the same, in that construction will fail if validation fails, but allows
implementers to utilize the instance method's convenience functions.
Previous implementations of `validate` would have been similar to this:
```python
@classmethod
def validate(payload: dict[str, Any]) -> bool:
# Check The Things™
return isinstance(payload, dict)
```
And will now need to be updated to this form:
```python
def validate(self) -> bool:
# Check The Things™
return isinstance(self._payload, dict)
```
## Development
Clone, install in editable mode with development and test requirements, and install the
**pre-commit** hooks:
```shell
git clone https://github.com/stac-utils/stac-task
cd stac-task
pip install -e '.[dev,test]'
pre-commit install
```
To run the tests:
```shell
pytest
```
To lint all the files:
```shell
pre-commit run --all-files
```
## Contributing
Use Github [issues](https://github.com/stac-utils/stac-task/issues) and [pull
requests](https://github.com/stac-utils/stac-task/pulls).