Actions and Triggers¶
Ryax supports actions in several languages.
python3
NodeJS
C#
Triggers are only supported in python3.
Here, we will describe what a Ryax python action is, what it consists of, as well as some technical functionalities made available.
You can find examples of actions and triggers in the Ryax default actions.
General¶
An action or a trigger requires at least 2 files: the python code in a .py
file, and the Ryax metadata file: ryax_metadata.yaml
. If the action has some external dependencies such as Pypi packages, or anything outside the python standard library (ex: pandas
, tensorflow
), it needs a standard requirements.txt
file with those dependencies listed on separate lines in plain text. You can also add a logo to your action, to easily identify it in the webui. This logo must be at most 250x250px
, and be in either jpg
or png
format.
Dependencies¶
Python dependencies¶
In a typical python3 program, you might need to install some dependencies for your program to work. The common approach is to have a file requirements.txt
with a list of all packages needed. Ryax will look at this file in the root of the action to know the external python libraries that are required by your code.
If your code does not have any external dependencies, you can omit this file.
Windows users must be careful because windows sometimes adds a .txt resulting in a requirements.txt.txt
.
A requirements.txt
file consists of a list of python dependencies, one per line. It is highly recommended to add version constraints to be sure that you always have the same version when your action is built:
pandas==2.1.4
tensorflow==1.3.0
pillow==7.0.0
You can look for all available python dependencies on Pypi.
Binary dependencies¶
If you have non-python dependencies (called “binary dependencies”), you can specify them in the dependencies
field of the ryax_metadata.yaml
file. It is possible that some python actions require a binary dependency to work, like opencv
. You can look for all supported dependencies, and their version, here. Some binaries might not work as Ryax run your code in a containerized and secured environment.
Metadata file¶
To describe your action, you need a ryax_metadata.yaml
file that contains a high-level description of your action and the inputs/outputs. The file ryax_metadata.yaml
follows the YAML standard.
Here is an example:
apiVersion: "ryax.tech/v2.0"
kind: Processor
spec:
id: tfdetection
human_name: Tag objects
description: "Tag detected objects on images using Tensorflow"
type: python3
version: "1.0"
logo: mylogo.png
dynamic_outputs: false
inputs:
- help: Model used to tag the images
human_name: Model name
name: model
type: enum
enum_values:
- ssdlite_mobilenet_v2_coco_2018_05_09
- mask_rcnn_inception_v2_coco_2018_01_28
default_value: ssdlite_mobilenet_v2_coco_2018_05_09
- help: An image to be tagged; in any format accepted by OpenCV
human_name: Image
name: image
type: file
outputs:
- help: Path of the tagged image
human_name: Tagged image
name: tagged_image
type: file
Some explanation on the fields:
kind
to tell the kind of the action: accepted values are Trigger, Processor, Publisherid
unique name of the actionversion
unique version of the actionhuman_name
a short name, readable by a humandescription
a description of the actiontype
the programming languagelogo
optional, a relative path to a logo file.
Note the field dynamic_outputs
as well. This is an optional field and will default to false. Only triggers may have dynamic outputs. This is useful in some cases such as when using an online form which can be filled out, to trigger workflows. This feature allows for the reuse of all the code for that trigger, while also allowing users to re-define the fields on that form in different workflows.
inputs
and outputs
contain the list of all the inputs and outputs (IOs) of this action:
name
: the name of your variable in your code. Is must not contain spaces or special characters except for_
. The input dict of you handler contains an entry with this name.human_name
: a human readable name.help
: describes your variable usage.type
: the action IO types. See the following table.optional
: whether your IO is optional or not. If true it will accept aNone
value.enum_values
(Only for enum type): a list of values accepted by your enum.default_value
(Optional and only for inputs): give a default value for this input.
Ryax Types¶
Ryax Actions IOs are typed. Here is the list of available types:
Type |
Description |
---|---|
string |
String of characters |
longstring |
Use for long text (Larger UI inputs) |
password |
String hidden on the UI |
integer |
64-bit integer |
float |
floating-point number |
boolean |
True of False |
enum |
Enumeration with a list of possible values |
file |
File (imported and exported by Ryax) |
directory |
Directory containing a set of files (imported and exported by Ryax) |
The code¶
Ryax knows how to call your code by importing a python code and starting a specific function in it.
Depending on the kind
of the action, we use 2 different filenames:
ryax_run.py
for triggersryax_handler.py
for all other actions
When creating a action, Ryax will copy all the files that are in the action directory. Thus, if you split your code in multiple files and use some resource files, they will be copied into the action.
Actions¶
The ryax_handler.py
file should contain a handle
method that takes a dict
as first parameter and returns a dict
or a list
of dict
.
def handle(request: dict)->dict:
a = request["an_integer_input"] # define in the `name` field
a = a + 42
return {
"output1": "value",
"output2": a,
}
By looking at this code, we can guess that this action has at least an input called an_integer_input
(an integer), and has 2 outputs: output1
and output2
. Ryax should know about these by describing them in the ryax_metadata.yaml
file.
The handle
function must return a dict
, it should contain an entry for all outputs of the action, with a valid value, as defined and typed in the ryax_metadata.yaml
file.
User defined errors¶
A common user-case in Ryax is to set up an API endpoint using the builtin HTTP API JSON
trigger. Likely you will want to configure your return codes alongside this. To do so, in your handler.py
file you may define an exception with the following signature:
from dataclasses import dataclass
@dataclass
class RyaxException(Exception):
message: str
code: int
And then in your handle code you may invoke that Exception as follows:
def handle(request: dict)->dict:
raise RyaxException(message="My error message", code = 404)
Raising the exception as done above will be caught by Ryax, and cancel the current run of your workflow. If this occurred in the context of an API endpoint, the endpoint will return the status code you have set, along with the error message.
Triggers¶
ryax_run.py
is the file to write your python code for a trigger. This script must contain a run
function that takes 2 paramaters: a dict
containing the inputs and an instance of the RyaxSourceProtocol
class.
import asyncio
from ryax_wrapper import RyaxSourceProtocol #optional import
async def run(service: RyaxSourceProtocol, input_values: dict) -> None:
while True:
text = source.inputs_values["input1"]
source.create_run({"output1": "hello "+text})
await asyncio.sleep(1)
In this particular case, we are creating an execution every second. We can guess that this action has 1 input called input1
and 1 output called output1
. Ryax should know about these by describing them in the ryax_metadata.yaml
file.
Here is the interface of RyaxSourceProtocol
:
class RyaxRunStatus(Enum):
DONE = 1
ERROR = 2
class RyaxSourceProtocol(metaclass=abc.ABCMeta):
async def create_run_error(self) -> None:
await self.create_run({}, status=RyaxRunStatus.ERROR)
@abc.abstractmethod
async def create_run(
self,
data: dict,
running_time: float = 0.001,
status: RyaxRunStatus = RyaxRunStatus.DONE,
) -> None:
...
def get_output_definitions(self) -> Dict[str, Any]:
...
Migrating from v1 to v2.0¶
Most of the specifications stay the same, except the following.
ryax_metadata.yaml
changes:
apiVersion: "ryax.tech/v2.0"
kind
changes:Gateways
is nowSource
,Functions
is nowProcessor
,Publishers
is nowPublisher
spec.detail
becomesspec.description
The requirements.txt
is now completly standard.
handler.py
has to be renamed ryax_handler.py
.
run.py
has to be renamed ryax_run.py
.
Also, the content has to be changed, we do not use a class anymore.
You have to use a run
function has explained in the documentation above.
If the ryax_metadata.yaml
file contains unknown fields, an error is thrown.