hello-world

Copyright (C) 2021, Axis Communications AB, Lund, Sweden. All Rights Reserved.

A minimal Python application

This example demonstrates how to create a simple Python application using the ACAP Computer Vision SDK and run it on an edge device.

Going from zero to a Python application running on an AXIS device is quite easy. First, the application script is written, as in the hello-world script in app/simply_hello.py. Next, the Dockerfile which build the application image is constructed. This needs to pull in packages from the ACAP Computer Vision SDK, as is done using the COPY commands. Finally, the application needs to be built and uploaded, as is specified below.

Example structure

Following are the list of files and a brief description of each file in the example

hello-world
├── app
├── |- simply_hello.py
├── Dockerfile
└── README.md

• simply_hello.py - A Python script that prints "Hello World"
• Dockerfile - Build instructions for the application image that is run on the camera

Requirements

To ensure compatibility with the examples, the following requirements shall be met:

• Camera: ARTPEC-{7-8} DLPU devices (e.g., Q1615 MkIII)
• docker-compose version 1.29 or higher
• Docker version 20.10.8 or higher
• Firmware: 10.9
• Docker ACAP installed and started, using TLS and SD card as storage

How to run the code

Export the environment variable for the architecture

Export the ARCH variable depending on the architecture of your camera

# For arm32
export ARCH=armv7hf
# For arm64
export ARCH=aarch64

Set your camera IP address define APP name and clear Docker memory

# Set camera IP
export AXIS_TARGET_IP=<actual camera IP address>
export DOCKER_PORT=2376

# Define APP name
export APP_NAME=hello-world

# Clean docker memory
docker --tlsverify -H tcp://$AXIS_TARGET_IP:$DOCKER_PORT system prune -af

Build and run the images

With the environment setup, the hello-world image can be built. The environment variables are supplied as build arguments such that they are made available to docker during the build process:

docker build . -t $APP_NAME --build-arg ARCH

Next, the built image needs to be uploaded to the device. This can be done through a registry or directly. In this case, the direct transfer is used by piping the compressed application directly to the device's docker client:

docker save $APP_NAME | docker --tlsverify -H tcp://$AXIS_TARGET_IP:$DOCKER_PORT  load

With the application image on the device, it can be started. As this example does not use e.g., OpenCV, no special mounts are needed, making the run command very simple:

docker --tlsverify -H tcp://$AXIS_TARGET_IP:$DOCKER_PORT run -it $APP_NAME

The expected output from the application is simply:

Hello World!

License

Apache License 2.0