Dockerized LEDE/OpenWRT image builder

What

Easily and quickly build LEDE or OpenWRT custom images using a self-contained docker container and the LEDE or OpenWrt image builder. On the builder host, Docker is the only requirement.

Note

The lede-dockerbuilder uses pre-compiled packages to build the final image. Look here if you are looking for a docker images to compile LEDE/OpenWRT completely from source.

Why

• customized and optimized (size) images with your personal configurations
• full automatic image creation (could be run in CI)
• reproducable results
• easy configuration, fast build (in minutes)

How

$ git clone https://github.com/jandelgado/lede-dockerbuilder.git
$ cd lede-dockerbuilder
$ ./builder.sh build example-nexx-wt3020.conf

Your custom images can now be found in the output diretory.

The build command will first build the docker image containing the LEDE image builder. The resulting docker image is per default tagged with lede-imagebuilder:<Release>-<Target>-<Subtarget>. Afterwards a container, which builds the actual LEDE image, is run. The final LEDE/OpenWRT image will be available in the output/ directory.

Usage

Dockerized LEDE/OpenWRT image builder.

Usage: ./builder.sh COMMAND CONFIGFILE [OPTIONS] 
  COMMAND is one of:
    build-docker-image- just build the docker image
    build             - build docker image, then start container and build the LEDE image
    shell             - start shell in docker container
  CONFIGFILE          - configuraton file to use

  OPTIONS:
  -o OUTPUT_DIR       - output directory 
  -f ROOTFS_OVERLAY   - rootfs-overlay directory 
  --skip-sudo         - call docker directly, without sudo

  command line options -o, -f, -r override config file settings.

Example:
  ./builder.sh build example.cfg -o output -f myrootfs

Configuration file

The configuration file is quiet self-explanatory. The following parameters are mandatory:

• LEDE_TARGET - Target architecture
• LEDE_SUBTARGET - Sub target architecture
• LEDE_RELEASE - LEDE release to use
• LEDE_PROFILE - LEDE profile to use
• LEDE_BUILDER_URL - URL of the LEDE image builder to use
• LEDE_PACKAGES - list of packages to include/exclude. Prepend package to be excluded with -.

LEDE_TARGET, LEDE_SUBTARGET and LEDE_RELEASE are used to construct the URL of the image builder binary, LEDE_BUILDER_URL as well as for the construction for the tag of the docker image.

You can find the proper values (for LEDE 17.01) by browsing the LEDE website here and here.

In addition the following optional parameters can be set, to further control output and image creation:

• OUTPUT_DIR - path where resulting images are stored. Defaults to output in the scripts directory (can be overridden by -o parameter)
• ROOTFS_OVERLAY - path of the root file system overlay directory. Defaults to rootfs-overlay in the scripts directory (can be overridden by -f parameter)

Use the BASEDIR_CONFIG_FILE variable to set locations of OUTPUT_DIR or ROOTFS_OVERLAY relative to the configuration files location. This allows self-contained projects outside of the lede-dockerbuilder folder. If e.g. ROOTFS_OVERLAY=$BASEDIR_CONFIG_FILE/rootfs-overlay is set, then the rootfs-overlay directory is expected to be in the same directory as the configuration file.

Example configuration for my NEXX WT3020 router, where I have an encrypted USB disk attached so I can use it as a simple NAS.

# LEDE profile to use
LEDE_PROFILE=wt3020-8M

# specify the URL where the builder can be downloaded.
LEDE_RELEASE=17.01.1
LEDE_TARGET=ramips
LEDE_SUBTARGET=mt7620
LEDE_BUILDER_URL="https://downloads.lede-project.org/releases/$LEDE_RELEASE/targets/$LEDE_TARGET/$LEDE_SUBTARGET/lede-imagebuilder-$LEDE_RELEASE-$LEDE_TARGET-$LEDE_SUBTARGET.Linux-x86_64.tar.xz"

# list packages to include in LEDE image. prepend packages to deinstall with "-".
LEDE_PACKAGES="samba36-server kmod-usb-storage kmod-scsi-core kmod-fs-ext4 ntfs-3g\
    kmod-nls-cp437 kmod-nls-iso8859-1 vsftpd cryptsetup kmod-crypto-xts\
    kmod-crypto-iv block-mount kmod-usb-ohci kmod-usb2 kmod-dm\
    kmod-crypto-misc kmod-crypto-cbc kmod-crypto-crc32c kmod-crypto-hash\
    kmod-crypto-user iwinfo tcpdump\
    -ppp -kmod-ppp -kmod-pppoe -kmod-pppox -ppp-mod-pppoe"

File system overlay

Place any files and folders that should be copied to the root file system of the resulting image to the directory pointed to by ROOTFS_OVERLAY (default: rootfs-overlay/), which can be overridden by the -f command line option.

Example directory structure

The following is an example directoy layout, which I use to create a customized LEDE image for my NEXX WT3020 router (including the generated output).

├── builder.sh
├── docker
│   ├── Dockerfile
│   └── etc
│        └── entrypoint.sh
├── example.cfg
├── example-openwrt.cfg
├── output
│   ├── lede-17.01.1-ramips-mt7620-device-wt3020-8m.manifest
│   ├── lede-17.01.1-ramips-mt7620-wt3020-8M-squashfs-factory.bin
│   ├── lede-17.01.1-ramips-mt7620-wt3020-8M-squashfs-sysupgrade.bin
│   └── sha256sums
├── README.md
└── rootfs-overlay
    ├── etc
    │   ├── config
    │   │   ├── dhcp
    │   │   ├── dropbear
    │   │   ├── firewall
    │   │   ├── network
    │   │   ├── samba
    │   │   ├── system
    │   │   ├── wireless
    │   ├── dropbear
    │   │   └── authorized_keys
    │   ├── hotplug.d
    │   │   └── block
    │   │       └── 10-mount
    │   ├── passwd
    │   ├── rc.local
    │   ├── shadow
    │   └── vsftpd.conf
    ├── README.md
    └── usr
        └── local
            └── bin
                └── fix_sta_ap.sh

Debugging

Run ./builder.sh shell CONFIGFILE to get a shell into the docker container, e.g. ./builder.sh shell example.cfg.

Building OpenWRT images

The file example-openwrt-wrt1043nd.conf contains an example which uses the OpenWRT image builder to create an image for the TP-Link WR1043ND router.

Examples

These examples evolved from images I use myself.

• Minimal LEDE image with LUCI web GUI for the Raspberry PI 2. Just ~8MB gziped. I use this image on my home dnsmasq/openvpn 'server'.
• OpenWRT image for the TP-Link WR1043ND
• LEDE image with samba, vsftpd and encrypted usb disk for NEXX-WT3020. Predessor of ...
• LEDE image with samba, vsftpd and encrypted usb disk for GINET-GL-M300N. This is my travel router setup where I have an encrypted USB disk connected to the router.

To build an example run ./builder.sh build <config-file>, e.g.

$ ./builder.sh build example-rpi2.conf 

The resulting image can be found in the output/ directory.

Author

Jan Delgado

License

Apache License 2.0