VyOS with Incus Agent Compilation Guide
This guide walks you through compiling VyOS with support for the Incus agent, which requires adding 9P filesystem support to the kernel configuration.
Prerequisites
- Docker installed on your system
- Git installed
- Sufficient disk space for kernel compilation
- Root/sudo access
Step 1: Clone VyOS Build Repository
First, clone the VyOS build repository and navigate to the kernel build directory:
git clone https://github.com/vyos/vyos-build.git
cd vyos-build/scripts/package-build/linux-kernel
Step 2: Clone Linux Kernel Source
Download the Linux kernel source code:
git clone https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Step 3: Configure Kernel for Incus Agent
Create the fix_9p_config.sh script (provided below) and make it executable:
chmod +x fix_9p_config.sh
Run the script to add 9P settings required for the Incus agent:
./fix_9p_config.sh arch/x86/configs/vyos_defconfig
This script will automatically configure the kernel with the necessary 9P filesystem support.
Step 4: Build the Kernel
Navigate back to the main VyOS build directory and start the Docker container:
cd ../../../ # Return to main vyos-build directory
docker run --rm -it --privileged -v $(pwd):/vyos -w /vyos vyos/vyos-build:current bash
Step 5: Install Dependencies and Build
Inside the Docker container, install the required build dependencies:
sudo su
apt install -y bc kmod libelf-dev libssl-dev flex bison python3 libpfm4 libtraceevent-dev libunwind-dev libdw-dev libdebuginfod-dev systemtap-sdt-dev libslang2-dev libperl-dev python3-dev
exit
Navigate to the kernel build directory and checkout the desired kernel version:
cd scripts/package-build/linux-kernel
git checkout <kernel_version> # Replace with your desired kernel version
./build-kernel.sh
Step 6: Copy Built Packages
Copy the generated .deb files to the main packages directory:
cp *.deb ../../../packages/
The following .deb files should be generated:
linux-headers-6.6.96-vyos_6.6.96-1_amd64.deblinux-image-6.6.96-vyos_6.6.96-1_amd64.deblinux-libc-dev_6.6.96-1_amd64.deblinux-perf-6.6.96-vyos_6.6.96-1_amd64.deb
Step 7: Add Incus Agent Package
Add the Incus agent .deb file to the same packages directory where you copied the kernel packages.
Step 8: Build VyOS ISO Image
From the main VyOS build directory, clean any previous builds and create the ISO image:
sudo make clean
sudo ./build-vyos-image --architecture amd64 --build-by "eminent" generic
Kernel Configuration Script
Below is the fix_9p_config.sh script that configures the kernel for 9P filesystem support:
#!/bin/bash
# 9P Kernel Configuration Fixer Script
# Usage: ./fix_9p_config.sh <defconfig_file>
set -e
# Check if file argument is provided
if [ $# -ne 1 ]; then
echo "Usage: $0 <defconfig_file>"
echo "Example: $0 arch/x86/configs/vyos_defconfig"
exit 1
fi
DEFCONFIG_FILE="$1"
# Check if file exists
if [ ! -f "$DEFCONFIG_FILE" ]; then
echo "Error: File '$DEFCONFIG_FILE' not found!"
exit 1
fi
echo "=== 9P Kernel Configuration Fixer ==="
echo "Processing file: $DEFCONFIG_FILE"
# Create backup
BACKUP_FILE="${DEFCONFIG_FILE}.backup.$(date +%Y%m%d_%H%M%S)"
cp "$DEFCONFIG_FILE" "$BACKUP_FILE"
echo "Backup created: $BACKUP_FILE"
# Define required 9P configurations
declare -a REQUIRED_CONFIGS=(
"CONFIG_NET_9P=y"
"CONFIG_NET_9P_FD=y"
"CONFIG_NET_9P_VIRTIO=y"
"CONFIG_NET_9P_XEN=m"
"CONFIG_NET_9P_RDMA=m"
"CONFIG_9PNET=y"
"CONFIG_9P_FS=y"
"CONFIG_9P_FSCACHE=y"
"CONFIG_9P_FS_POSIX_ACL=y"
"CONFIG_9P_FS_SECURITY=y"
"CONFIG_FSCACHE=y"
"CONFIG_CACHEFILES=y"
"CONFIG_VIRTIO_PCI=y"
"CONFIG_VIRTIO=y"
"CONFIG_VIRTIO_CONSOLE=y"
"CONFIG_NETWORK_FILESYSTEMS=y"
"CONFIG_NETFS_SUPPORT=y"
)
# Define configs to check for conflicts (both enabled and disabled forms)
declare -a CONFLICT_PATTERNS=(
"CONFIG_NET_9P"
"CONFIG_9PNET"
"CONFIG_9P_FS"
"CONFIG_9P_FSCACHE"
"CONFIG_9P_FS_POSIX_ACL"
"CONFIG_9P_FS_SECURITY"
"CONFIG_FSCACHE"
"CONFIG_CACHEFILES"
"CONFIG_VIRTIO_PCI"
"CONFIG_VIRTIO"
"CONFIG_VIRTIO_CONSOLE"
"CONFIG_NETWORK_FILESYSTEMS"
"CONFIG_NETFS_SUPPORT"
)
echo ""
echo "=== Step 1: Checking for conflicting entries ==="
# Remove all existing instances of these configs (both enabled and disabled)
for pattern in "${CONFLICT_PATTERNS[@]}"; do
# Count how many instances exist
count=$(grep -c "^${pattern}=" "$DEFCONFIG_FILE" 2>/dev/null || true)
disabled_count=$(grep -c "^# ${pattern} is not set" "$DEFCONFIG_FILE" 2>/dev/null || true)
if [ "$count" -gt 0 ] || [ "$disabled_count" -gt 0 ]; then
echo " Found conflicts for $pattern: $count enabled, $disabled_count disabled"
# Remove all instances (enabled and disabled)
sed -i "/^${pattern}=/d" "$DEFCONFIG_FILE"
sed -i "/^# ${pattern} is not set/d" "$DEFCONFIG_FILE"
echo " Removed all instances of $pattern"
fi
done
echo ""
echo "=== Step 2: Adding required 9P configurations ==="
# Find a good place to insert configs (after comments, before first real config)
insert_line=$(grep -n "^CONFIG_" "$DEFCONFIG_FILE" | head -1 | cut -d: -f1)
if [ -z "$insert_line" ]; then
# If no CONFIG lines found, add at end of file
insert_line=$(wc -l < "$DEFCONFIG_FILE")
((insert_line++))
else
# Insert before first CONFIG line
((insert_line--))
fi
echo " Inserting configs at line $insert_line"
# Create temporary file with new configs
temp_file=$(mktemp)
# Add header comment
echo "# 9P Filesystem Support (Added by fix_9p_config.sh)" >> "$temp_file"
# Add all required configs
for config in "${REQUIRED_CONFIGS[@]}"; do
echo "$config" >> "$temp_file"
echo " Added: $config"
done
echo "" >> "$temp_file"
# Insert the new configs into the original file
head -n "$insert_line" "$DEFCONFIG_FILE" > "${temp_file}.part1"
tail -n +$((insert_line + 1)) "$DEFCONFIG_FILE" > "${temp_file}.part2"
cat "${temp_file}.part1" "$temp_file" "${temp_file}.part2" > "$DEFCONFIG_FILE"
# Cleanup temp files
rm -f "$temp_file" "${temp_file}.part1" "${temp_file}.part2"
echo ""
echo "=== Step 3: Verification ==="
# Verify all required configs are present and no conflicts remain
echo " Checking for required configs:"
all_present=true
for config in "${REQUIRED_CONFIGS[@]}"; do
if grep -q "^${config}$" "$DEFCONFIG_FILE"; then
echo " ✓ $config"
else
echo " ✗ $config - NOT FOUND!"
all_present=false
fi
done
echo ""
echo " Checking for remaining conflicts:"
conflicts_found=false
for pattern in "${CONFLICT_PATTERNS[@]}"; do
# Check for duplicates
count=$(grep -c "^${pattern}=" "$DEFCONFIG_FILE" 2>/dev/null || true)
disabled_count=$(grep -c "^# ${pattern} is not set" "$DEFCONFIG_FILE" 2>/dev/null || true)
if [ "$count" -gt 1 ]; then
echo " ⚠ WARNING: Multiple enabled entries for $pattern ($count found)"
conflicts_found=true
fi
if [ "$disabled_count" -gt 0 ]; then
echo " ⚠ WARNING: Disabled entries still present for $pattern ($disabled_count found)"
conflicts_found=true
fi
done
echo ""
echo "=== Summary ==="
if [ "$all_present" = true ] && [ "$conflicts_found" = false ]; then
echo "✅ SUCCESS: All 9P configurations added successfully!"
echo "✅ No conflicts detected."
else
echo "❌ Issues detected. Please review the warnings above."
fi
echo ""
echo "📁 Original file backed up to: $BACKUP_FILE"
echo "📝 Modified file: $DEFCONFIG_FILE"
echo ""
echo "Next steps:"
echo "1. Review the changes: diff $BACKUP_FILE $DEFCONFIG_FILE"
echo "2. Build the kernel: ./build-kernel.sh"
echo "3. Verify 9P support: grep 9P linux/.config"
exit 0
What This Process Does
-
Kernel Configuration: The script automatically adds 9P filesystem support to the VyOS kernel configuration, which is essential for the Incus agent to function properly.
-
9P Filesystem: This provides the communication channel between the Incus host and the VyOS container, allowing for file sharing and agent communication.
-
Custom Build: Creates a custom VyOS image with Incus agent support built-in.
Troubleshooting
- Build Failures: Ensure all dependencies are installed and you have sufficient disk space
- 9P Support: Verify 9P support is enabled by checking
grep 9P linux/.configafter kernel build - Container Issues: Make sure Docker has sufficient privileges and resources allocated
Notes
- Replace
<kernel_version>with the specific kernel version you want to build (e.g.,v6.6.96) - The build process may take considerable time depending on your system specifications
- Ensure you have the correct Incus agent .deb package for your target architecture