Docker support

Firefly normal firmware generally does not meet Docker operation
requirements. If there is a need, you can use SDK to enable related
kernel configs and rebuild the kernel to support Docker.

(RK356X v1.2.4a and later version, RK3399/RK3588 support Docker by
default, you can skip straight to the installation step)

The following case is based on Firefly Ubuntu 20.04, and the kernel
configuration part is generic!

Check Kernel Configuration

First use script to see which configuration is needed by Docker but
missing in current kernel. You can get the check script from

GitHub

.

After get the script, begin to check:

   #Copy the script to SDK/kernel/
   cp check-config.sh PathToSDK/kernel/
   cd PathToSDK/kernel
   chmod +x check-config.sh

   #Get current kernel configuration
   make ARCH=arm64 firefly_linux_defconfig

   #Check
   ./check-config.sh .config

The result looks like this, mainly two parts:

   Generally Necessary:
   - cgroup hierarchy: properly mounted [/sys/fs/cgroup]
   - apparmor: enabled and tools installed
   - CONFIG_NAMESPACES: enabled
   - CONFIG_NET_NS: enabled
   - CONFIG_PID_NS: enabled
   - CONFIG_IPC_NS: enabled
   - CONFIG_UTS_NS: enabled
   - CONFIG_CGROUPS: enabled
   ......

   Optional Features:
   - CONFIG_USER_NS: enabled
   - CONFIG_SECCOMP: enabled
   - CONFIG_SECCOMP_FILTER: enabled
   - CONFIG_CGROUP_PIDS: enabled
   - CONFIG_MEMCG_SWAP: enabled
   ......

Generally Necessary: All features in this part need to be enabled in
kernel.

Optional Features: Enable them as you needed.

Enable Needed Features

From the result you can find out which features are need to be
enabled, then use "make ARCH=arm64 menuconfig" to enter config menu,
search and enable them. Please read the instructions in the config
menu, if some features can't be selected, check the dependency.

Enabled all the necessary features and some optional features,
remember to save:

   make ARCH=arm64 savedefconfig
   mv defconfig arch/arm64/configs/firefly_linux_defconfig

Compile the kernel:

   #Back to SDK dir
   cd ..
   #Compile
   ./build.sh kernel

Install Docker

After burning new kernel, install Docker on device (This method works
on PC as well)

Step1：Quick install

   # Here only introduces the quick-install using script
   apt-get update
   wget -qO- https://get.docker.com/ | sh

You should see the Docker version information after the installation
is successful.

Step2：Check docker root dir (This step is only for PC docker
installing)

If you are installing docker in Firefly device, please skip this step.

   # execute
   docker info | grep -i dir
   # result
    Docker Root Dir: /var/lib/docker

The result shows docker root dir, this location may be different on
different PC.

Images and containers need large disk space,

if the default location does not have enough space, you need to change
the default location to one with sufficient space.

Emphasize again：This step is only for PC, in Firefly device, change
this dir will cause docker error

, please go to next step.

   # stop docker service first
   sudo systemctl stop docker

   # modify /lib/systemd/system/docker.service
   sudo vim /lib/systemd/system/docker.service

   # add your destination dir at the end of ExecStart line: --graph /home/firefly/docker/data
   ExecStart=/usr/bin/dockerd -H fd:// --containerd=/run/containerd/containerd.sock --graph /home/firefly/docker/data

   # start docker service
   sudo systemctl daemon-reload
   sudo systemctl start docker

   # check if the location is updated
   docker info | grep -i dir
    Docker Root Dir: /home/firefly/docker/data

Step3：add your user to docker group

   sudo usermod -a -G docker firefly
   # reboot
   sudo reboot

Step4：After reboot, run demo to test docker:

   firefly@firefly:~# docker run hello-world
   Unable to find image 'hello-world:latest' locally
   latest: Pulling from library/hello-world
   93288797bd35: Pull complete
   Digest: sha256:cc15c5b292d8525effc0f89cb299f1804f3a725c8d05e158653a563f15e4f685
   Status: Downloaded newer image for hello-world:latest

   Hello from Docker!
   This message shows that your installation appears to be working correctly.

   To generate this message, Docker took the following steps:
    1. The Docker client contacted the Docker daemon.
    2. The Docker daemon pulled the "hello-world" image from the Docker Hub.
       (arm64v8)
    3. The Docker daemon created a new container from that image which runs the
       executable that produces the output you are currently reading.
    4. The Docker daemon streamed that output to the Docker client, which sent it
       to your terminal.

   To try something more ambitious, you can run an Ubuntu container with:
    $ docker run -it ubuntu bash

   Share images, automate workflows, and more with a free Docker ID:
    https://hub.docker.com/

   For more examples and ideas, visit:
    https://docs.docker.com/get-started/