Python Reference

On This Page

This document describes specific Python build and deploy configurations.

Function and handler

def handler(context, event):
    return ""

The handler field is of the form <package>:<entrypoint>, where <package> is a dot (.) separated path (for example, foo.bar equates to foo/bar.py) and <entrypoint> is the function name. In the example above, the handler is main:handler, assuming the file is named main.py.

Dockerfile

Following is sample Dockerfile code for deploying a Python function. For more information, see Deploying Functions from a Dockerfile.

Note
Make sure to replace my-function-code and my-function.yaml in the following example with the names of your function and function-configuration file.
ARG NUCLIO_LABEL=1.1.18
ARG NUCLIO_ARCH=amd64
ARG NUCLIO_BASE_IMAGE=python:3.6-jessie
ARG NUCLIO_ONBUILD_IMAGE=quay.io/nuclio/handler-builder-python-onbuild:${NUCLIO_LABEL}-${NUCLIO_ARCH}

# Supplies processor uhttpc, used for healthcheck
FROM nuclio/uhttpc:0.0.1-amd64 as uhttpc

# Supplies processor binary, wrapper
FROM ${NUCLIO_ONBUILD_IMAGE} as processor

# From the base image
FROM ${NUCLIO_BASE_IMAGE}

# Copy required objects from the suppliers
COPY --from=processor /home/nuclio/bin/processor /usr/local/bin/processor
COPY --from=processor /home/nuclio/bin/py /opt/nuclio/
COPY --from=uhttpc /home/nuclio/bin/uhttpc /usr/local/bin/uhttpc

RUN pip install nuclio-sdk msgpack --no-index --find-links /opt/nuclio/whl

# Readiness probe
HEALTHCHECK --interval=1s --timeout=3s CMD /usr/local/bin/uhttpc --url http://127.0.0.1:8082/ready || exit 1

# USER CONTENT
ADD ./my-function-code /opt/nuclio
ADD ./my-function.yaml /etc/nuclio/config/processor/processor.yaml
# END OF USER CONTENT

# Run processor with configuration and platform configuration
CMD [ "processor" ]

Function configuration

Your function-configuration file (for example, my-function.yaml for the example Dockerfile) must include the name of your handler function and Python runtime. For more information, see the function-configuration reference. For example:

spec:
  handler: main:handler
  runtime: python:3.6

Build and execution

Following are example commands for building and running the latest version of a my-function function that’s listening on port 8090; replace the function name and version and the port number, as needed:

docker build -t my-function:latest .
docker run --name my-function --rm -d -p 8090:8080 my-function:latest