[Yocto] 01_Building Yocto Images using a Docker Container
Building a Yocto image requires a specific set of Operating System dependencies that might make it challenging to run on a non-dedicated machine. Over time it can be difficult to maintain a known-good environment that will work with a number of different versions of the Yocto project. One solution to this is to use a Docker container to create a known-good build environment, containing the necessary packages and Operating System version.
1. Introduction
The creation of a Docker container can be achieved in a number of ways. This specific guide shows how to install the bare minimum infrastructure to build Yocto images for NXP hardware while storing the generated build artifacts outside of the container itself. The Docker container will mount local folders on the host machine, and no persistent data will be stored within the Docker container filesystem. This has the advantage of not requiring containers to be part of a backup strategy, and allows for a very lightweight build environment.
2. Installation of Docker Engine on a Linux machine
The process to install Docker on a host Linux machine can vary based on the operating system that is being run natively. Please follow the instructions at Install Docker Engine to install the Docker engine. Be sure to also follow the post-installation steps at Linux post-installation steps for Docker Engine in order to allow users to run Docker without root/sudo access. The remaining sections assume that this has all been completed successfully, and as a user, you are able to successfully run the “hello world” docker test image:
$ docker run hello-world
Unable to find image 'hello-world:latest' locally
latest: Pulling from library/hello-world
c1ec31eb5944: Pull complete
Digest: sha256:4bd78111b6914a99dbc560e6a20eab57ff6655aea4a80c50b0c5491968cbc2e6
Status: Downloaded newer image for hello-world:latest
Hello from Docker!
This message shows that your installation appears to be working correctly.
Building a Docker Image
On your host machine, create a new directory, and and create the following contents as a file “Dockerfile”.
This Dockerfile shall create a base Ubuntu 16.04 OS image, and install the necessary packages and additional tools required to build IMX6 Yocto Images. A user “build” is also created within the container, and shall be used for the build process.
Build your Docker image using the following command, making sure you are in the directory containing the Dockerfile. You can choose a different name to “yoctocontainer” if you prefer. Ensure you also change the name appropriately when running the docker run command if you do.
docker build -t yoctocontainer .
Building will take around a minute, depending on bandwidth to download the dependencies. On subsequent builds, downloads will be cached and so will be substantially quicker. The build command only needs to be run once, unless you modify the Dockerfile to include new packages or tools.
Once the image is created, you can change to any directory on your host. There is now no dependency on the Dockerfile being in the current directory (or even existing), as the configuration of “yoctocontainer” is centrally managed on your machine.
The docker run command can now be executed. The -v options below share folders between the host and the docker image. This is important to note as the docker container will be run in a mode where no data local to the docker machine will survive a relaunch!
As a result, the example below uses the current working directory (pwd) and mounts it as a folder /home/build/work. As long as you change directory and run all of your Yocto commands as a folder within work, this will remain on your target system after docker has finished. Feel free to add additional paths to the example shown below, and remove unused paths:
This Docker image is purposefully minimal - it is intended to be a build environment only! This means, you will not find common editing tools such as vi or nano, as files should be modified on the host, and the docker image used to build the image. Always work in a mounted filesystem (such as ~/build/work) to ensure that your data persists across sessions!
Once completed, you can quit back to your host shell using the exit command. The next invocation of the container will be “fresh” as no data persists across runs, outside of that mounted from the host Operating System.
Storing the Docker Image your built
# carlos @ asus_carlos in ~/storage [8:38:33]
$ docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
9875b7bc364f yoctocontainer "/bin/bash" 2 hours ago Up 2 hours stupefied_cori
415aa304458a carloswei/ubuntu1804_emb:v1 "/bin/bash" 24 hours ago Up 24 hours quizzical_franklin
20041bc19285 carloswei/ubuntu2004_emb:v1 "/bin/bash" 25 hours ago Exited (0) 25 hours ago temp_v2
# carlos @ asus_carlos in ~/storage [10:17:26]
$ docker commit -a 'Carlos Wei' -m "yocto built finished" 9875b7bc364f yoctocontainer:v1
sha256:69c437f498c45ab88f6e9a712ba36d5008ebe7c5e1631bea2ffd773e06be9279
# carlos @ asus_carlos in ~/storage [10:18:32]
$ docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
yoctocontainer v1 69c437f498c4 6 seconds ago 1.05GB
yoctocontainer latest 9a3a326304a7 2 hours ago 1.04GB
carloswei/ubuntu2404_emb v1 2be5a661285e 46 hours ago 5.7GB
carloswei/ubuntu2204_emb v1 ae73c0d02a2f 46 hours ago 5.6GB
carloswei/ubuntu2004_emb v1 37ba311ea955 47 hours ago 5.51GB
carloswei/ubuntu1804_emb v1 a9b6f5e2daf5 47 hours ago 5.31GB
carloswei/ubuntu1604_emb v1 2e6eea371ac2 2 days ago 5.29GB
[Yocto] 01_Building Yocto Images using a Docker Container
Building a Yocto image requires a specific set of Operating System dependencies that might make it challenging to run on a non-dedicated machine. Over time it can be difficult to maintain a known-good environment that will work with a number of different versions of the Yocto project. One solution to this is to use a Docker container to create a known-good build environment, containing the necessary packages and Operating System version.
1. Introduction
The creation of a Docker container can be achieved in a number of ways. This specific guide shows how to install the bare minimum infrastructure to build Yocto images for NXP hardware while storing the generated build artifacts outside of the container itself. The Docker container will mount local folders on the host machine, and no persistent data will be stored within the Docker container filesystem. This has the advantage of not requiring containers to be part of a backup strategy, and allows for a very lightweight build environment.
2. Installation of Docker Engine on a Linux machine
The process to install Docker on a host Linux machine can vary based on the operating system that is being run natively. Please follow the instructions at Install Docker Engine to install the Docker engine. Be sure to also follow the post-installation steps at Linux post-installation steps for Docker Engine in order to allow users to run Docker without root/sudo access. The remaining sections assume that this has all been completed successfully, and as a user, you are able to successfully run the “hello world” docker test image:
Building a Docker Image
On your host machine, create a new directory, and and create the following contents as a file “Dockerfile”.
https://github.com/carloscn/dockerhub/tree/master/ubuntu1604
https://github.com/carloscn/dockerhub/blob/master/ubuntu1604/Dockerfile
This Dockerfile shall create a base Ubuntu 16.04 OS image, and install the necessary packages and additional tools required to build IMX6 Yocto Images. A user “build” is also created within the container, and shall be used for the build process.
Build your Docker image using the following command, making sure you are in the directory containing the Dockerfile. You can choose a different name to “yoctocontainer” if you prefer. Ensure you also change the name appropriately when running the docker run command if you do.
docker build -t yoctocontainer .Building will take around a minute, depending on bandwidth to download the dependencies. On subsequent builds, downloads will be cached and so will be substantially quicker. The build command only needs to be run once, unless you modify the Dockerfile to include new packages or tools.
Once the image is created, you can change to any directory on your host. There is now no dependency on the Dockerfile being in the current directory (or even existing), as the configuration of “yoctocontainer” is centrally managed on your machine.
The docker run command can now be executed. The -v options below share folders between the host and the docker image. This is important to note as the docker container will be run in a mode where no data local to the docker machine will survive a relaunch!
As a result, the example below uses the current working directory (pwd) and mounts it as a folder /home/build/work. As long as you change directory and run all of your Yocto commands as a folder within work, this will remain on your target system after docker has finished. Feel free to add additional paths to the example shown below, and remove unused paths:
https://github.com/carloscn/dockerhub/blob/master/ubuntu1604/run_your_build_docker.sh
Once completed, you can quit back to your host shell using the exit command. The next invocation of the container will be “fresh” as no data persists across runs, outside of that mounted from the host Operating System.
Storing the Docker Image your built
Reference