Guide to Installing OECT and Deploying OpenWrt in LXC

1️⃣ Main System Selection

OECT has recently gained popularity, and after acquiring it, I considered flashing the firmware. The K2P + N1 has met most of my home network needs, and with OECT’s 4GB of RAM, running OpenWrt separately would be too extravagant, so I decided on the Main System: Armbian.

Let the professionals handle professional tasks:

• Armbian as the main system
• Deploying OpenWrt through LXC containers, sharing the kernel with Armbian, without interfering with the main system

2️⃣ Flashing Considerations

• Use the top Type-C interface for flashing, do not connect the power cable
• Do not unplug the SATA cable forcefully
• Short the GND and 1V8 (it is recommended to use the DEBUG point for GND)
• Flashing tool configuration:
• Address 0xCCCCCCCC Name LoaderToDDR
• Address 0x00000000 Name system

3️⃣ Creating br0 Bridge (Armbian)

Armbian creates a br0 bridge, bridging the host’s physical network card and the LXC/OpenWrt container network, allowing the container to behave like a real independent device on the local network.

Edit the Netplan configuration:

network:

  version:2

  renderer: networkd  

  ethernets:

    eth0:{}

  bridges:

    br0:

      interfaces:[eth0]

      addresses:[192.168.1.10/24]# Change to your internal IP

      routes:

        -to: default          

        via: 192.168.1.1          # Main router IP

      nameservers:

        addresses:[8.8.8.8, 1.1.1.1]

YAML

Apply configuration:

sudo netplan apply

ip addr show

Bash

4️⃣ Change to Tsinghua Source

vi /etc/apt/sources.list.d/ubuntu.sources

# Comment out the original source, add:

URIs: https://mirrors.tuna.tsinghua.edu.cn/ubuntu/LXC

Bash

5️⃣ Install LXC

sudo apt update

sudo apt install lxc bridge-utils

Bash

Why Choose LXC Instead of LXD

• LXC is like Docker without a GUI
• LXD simplifies LXC commands but requires Snap, which takes up more space and has poor interoperability between containers and the main system
• OECT has limited space, so I decisively run LXC bare-metal

6️⃣ Configure OpenWrt Container

sudo mkdir -p /var/lib/lxc/openwrt

sudo mkdir -p /var/lib/lxc/openwrt/rootfs

vi /var/lib/lxc/openwrt/config

Example content:

# Container configuration

lxc.include = /usr/share/lxc/config/common.conf

lxc.arch = aarch64

# Container specific configuration

lxc.apparmor.profile = unconfined

lxc.apparmor.allow_nesting = 1

lxc.rootfs.path = dir:/var/lib/lxc/openwrt/rootfs

lxc.uts.name = openwrt

lxc.start.auto = 1

lxc.start.delay = 20

# Network

lxc.net.0.type = veth

lxc.net.0.link = br0

lxc.net.0.flags = up

# TUN/TAP

lxc.cgroup2.devices.allow = c 10:200 rwm

lxc.mount.entry = /dev/net/tun dev/net/tun none bind,create=file

Ini

7️⃣ Download and Install OpenWrt Image

There are two types of images: original OpenWrt images and domestic OpenWrt branch images.

Original Image

1. The method to install OpenWrt from the original image can be found at: https://images.lxd.canonical.com/. Enter the webpage, select the appropriate version of OpenWrt, click the date to download the two files in the red box, and upload them to the root folder.

# Download rootfs and extract

sudo apt install squashfs-tools

unsquashfs rootfs.squashfs

cp -a squashfs-root/* /var/lib/lxc/openwrt/rootfs/

tar -xJf lxd.tar.xz -C /var/lib/lxc/openwrt/rootfs/

Bash

Domestic Branch Images (immortalwrt/istoreOS)

2. The method to install OpenWrt from domestic branch images is numerous, with immortalwrt and istoreOS being the most popular. Both of these firmware formats are img.gz, rename using mv to openwrt.img.gz and then enter the following commands.

gzip -d openwrt.img.gz

fdisk -l openwrt.img

Bash

The screen will show loop1 and loop2, calculate the offset, offset=$((START_SECTOR * 512)), multiply the start value of the large partition by 512 to get the offset value. Substitute this value into the following offset.

mkdir /mnt/openwrt

mount -o loop,offset=$offset openwrt.img /mnt/openwrt

cp -a /mnt/openwrt/* /var/lib/lxc/openwrt/rootfs/

Bash

8️⃣ Start OpenWrt Container

lxc-start openwrt

Bash

9️⃣ Common LXC Commands

# Create and configure

lxc-create        # Create container

lxc-config        # Display/modify LXC configuration

lxc-update-config # Update old version configuration files

# Start and run

lxc-start         # Start container

lxc-execute       # Start container and execute command

lxc-attach        # Attach to running container

lxc-console       # Open container console

lxc-autostart     # Start all containers set to autostart

lxc-usernsexec    # Execute command in user namespace

lxc-unshare       # Open new namespace to execute command

# Stop and destroy

lxc-stop          # Stop container

lxc-destroy       # Delete container

# Query and monitor

lxc-ls            # List all containers

lxc-info          # View container information

lxc-monitor       # Monitor container events

lxc-top           # Show container resource usage

lxc-wait          # Wait for container to reach specified state

# Snapshot and copy

lxc-copy          # Copy container

lxc-snapshot      # Snapshot operations (create/list/recover)

# State management

lxc-freeze        # Freeze container (pause processes)

lxc-unfreeze      # Unfreeze container (resume processes)

# Device and resource

lxc-cgroup        # Manage container's cgroup parameters

lxc-device        # Manage container device mapping# Advanced features

lxc-checkconfig   # Check kernel support for LXC

lxc-checkpoint    # Container checkpoint/recovery (requires criu)

Bash

References

1. Little Rice Needs to Eat – Bilibili
2. fitnessele – Enshan Forum
3. hereyes – Enshan Forum