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OSCAR Service

OSCAR allows the creation of serverless file-processing services based on container images. These services require a user-defined script with the commands responsible of the processing. The platform automatically mounts a volume on the containers with the FaaS Supervisor component, which is in charge of:

  • Downloading the file that invokes the service and make it accessible through the INPUT_FILE_PATH environment variable.
  • Execute the user-defined script.
  • Upload the content of the output folder accessible via the TMP_OUTPUT_DIR environment variable.


FaaS Supervisor, the component in charge of managing the input and output of services, allows JSON or base64 encoded body in service requests. The body of these requests will be automatically decoded into the invocation's input file available from the script through the $INPUT_FILE_PATH environment variable.

The output of synchronous invocations will depend on the application itself:

  1. If the script generates a file inside the output dir available through the $TMP_OUTPUT_DIR environment variable, the result will be the file encoded in base64.
  2. If the script generates more than one file inside $TMP_OUTPUT_DIR, the result will be a zip archive containing all files encoded in base64.
  3. If there are no files in $TMP_OUTPUT_DIR, FaaS Supervisor will return its logs, including the stdout of the user script run. To avoid FaaS Supervisor's logs, you must set the service's log_level to CRITICAL.

This way users can adapt OSCAR's services to their own needs.

You can follow one of the examples in order to test the OSCAR framework for specific applications. We recommend you to start with the plant classification example.