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HOWTO Docker

Docker is a platform that lets you package, ship, and run applications in lightweight, portable units called containers.

Docker makes it easy to run an application the same way everywhere—on your laptop, a server, or in the cloud—without worrying about differences in operating systems or installed software.

Install Docker on IGEL OS

NOTE: Need to run docker as root.

Test Docker with hello-world

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docker run hello-world
What happens internally:

  • Docker checks if the hello-world image exists locally
  • If not, it pulls it from Docker Hub
  • Docker creates and runs a container
  • The container prints a message and exits

Docker Examples

  • Setup Debian Bookworm (12)
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docker run --network host -it debian:bookworm bash -c \
"apt-get update && apt-get install -y curl iputils-ping && bash"
  • Setup Ubuntu 22.04
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docker run --network host -it ubuntu:22.04 bash -c \
"apt-get update && apt-get install -y curl iputils-ping && bash"
  • List docker images
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docker images
  • Run debian:bookworm
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docker run --network host -it debian:bookworm
  • Run ubuntu:22.04
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docker run --network host -it ubuntu:22.04

Use Docker to collect latest deb files

Summary of steps:

  • Create dockerfile
  • Create get-debs.sh to collect deb files
  • Run docker to collect the files and save into artifacts folder

Save the following as dockerfile:

# Choose a base image
FROM debian:bookworm AS build

# Set a working directory inside the image
WORKDIR /tmp
COPY . .

# Copy deb collection script
COPY get-debs.sh .

# Install dependencies
RUN apt update && apt-get install -y curl gnupg

# run get-debs to collect the deb files
RUN bash ./get-debs.sh

# copy deb files to out folder
RUN mkdir -p /out
RUN cp -v *.deb /out/
RUN cp -v deb-listing.txt /out/

# copy files out of container
FROM scratch AS export
COPY --from=build /out/ /

Save the following as get-debs.sh:

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#!/bin/bash
#set -x
#trap read debug

MISSING_LIBS="containerd.io docker-buildx-plugin docker-ce docker-ce-cli docker-ce-rootless-extras docker-compose-plugin"

apt install curl -y

curl -fsSL https://download.docker.com/linux/debian/gpg | gpg --dearmor -o /etc/apt/keyrings/docker.gpg

echo \
"deb [arch=amd64 signed-by=/etc/apt/keyrings/docker.gpg] \
https://download.docker.com/linux/debian \
bookworm stable" | \
tee /etc/apt/sources.list.d/docker.list > /dev/null

apt-get update

mkdir build_tar
cd build_tar

for lib in $MISSING_LIBS; do
  apt-get download $lib
  ls $lib* >> deb-listing.txt
  mv $lib*.deb $lib.deb
done

mv *.deb ..
mv deb-listing.txt ..
cd ..
rm -rf build_tar

Run Docker with the following commands:

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mkdir -p artifacts
docker system prune -f
docker buildx build --network host --target export --output type=local,dest=./artifacts .
  • The deb files will be in the artifacts folder

Using IGEL OS App SDK Docker image

Summary of steps:

  • Download IGEL OS App SDK Docker image from IGEL App Creator Portal
  • Load the docker image
  • Create dockerfile
  • Zip up the recipe and any needed files into recipe.zip
  • Run docker to build the image, collect the certificates, create zip file of results, and save into artifacts folder

Load the docker image

Note: Docker must be run as root

docker load < igelpkg.tar

Create recipe.zip

Save the following as dockerfile:

# Choose a base image
FROM igelpkg:latest AS build

# Set a working directory inside the image
WORKDIR /tmp
COPY . .

# Copy zip of recipe and any needed files
RUN rm -rf /tmp/*
COPY recipe.zip .

# Install dependencies
RUN apt update && apt-get install -y zip

# unzip recipe
RUN unzip recipe.zip
RUN rm recipe.zip

# run igel packager
RUN igelpkg build -r bookworm -a x64 -sp -sa -l -sr

# copy certs
RUN cp /usr/share/igelpkg/certs/IGEL_OS_12_SDK-intermediate.crt .
RUN cp /usr/share/igelpkg/certs/IGEL_OS_12_SDK-leaf.crt .

# create zip file and copy to out folder
RUN mkdir -p /out
RUN zip -r build_results.zip *
RUN cp -v build_results.zip /out/

# copy files out of container
FROM scratch AS export
COPY --from=build /out/ /

Run Docker with the following commands:

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mkdir -p artifacts
docker system prune -f
docker buildx build --network host --target export --output type=local,dest=./artifacts .
  • The zip, build_results.zip, file will be in the artifacts folder