ansible-openwisp2-imagegenerator

This ansible role allows to build several openwisp2 firmware images for different organizations while keeping track of their configurations.

NOTE: this role has not been tested in the wild yet. If you intend to use it, try it out and if something goes wrong please proceed to report your issue, but bear in mind you need to be willing to understand the build process and it's inner working in order to make it work for you.

Required role variables

The following variables are required:

• openwisp2fw_source_dir: indicates the directory of the OpenWRT source that is used during compilation
• openwisp2fw_generator_dir: indicates the directory used for the preparation of generators
• openwisp2fw_bin_dir: indicates the directory used when building the final images
• openwisp2fw_organizations: a list of organizations; see the example playbook.yml file in the create playbook section to understand its structure

Usage (tutorial)

If you don't know how to use ansible, don't panic, this procedure will guide you step by step.

If you already know how to use ansible, you can skip this section and jump straight to the "Install this role" section.

First of all you need to understand two key concepts:

• for "compilation server" we mean a server which is used to compile the images
• for "local machine" we mean the host from which you launch ansible, eg: your own laptop or CI server

Ansible is a configuration management/automation tool that works by entering the compilation server via SSH and executing a series of commands.

1. Install ansible

Install ansible on your local machine if you haven't done already, there are various ways in which you can do this, but we prefer to use the official python package manager, eg:

sudo pip install ansible

If you don't have pip installed see Installing pip on the pip documentation website.

Installing ansible in other ways is fine too, just make sure to install a version of the 2.0.x series (which is the version with which we have tested this playbook).

2. Install this role

For the sake of simplicity, the easiest thing is to install this role on your local machine via ansible-galaxy (which was installed when installing ansible), therefore run:

sudo ansible-galaxy install openwisp.openwisp2-imagegenerator

3. Choose a working directory

Choose a working directory on your local machine where to put the configuration of your firmware images.

Eg:

mkdir ~/my-openwisp2-firmware-conf
cd ~/my-openwisp2-firmware-conf

Putting this working directory under version control is also a very good idea, it will help you to track change, rollback, set up a CI server to automatically build the images for you and so on.

4. Create inventory file

The inventory file is where group of servers are defined. In our simple case we can get away with defining a group in which we will put just one server.

Create a new file hosts on your local machine with the following contents:

[myserver]
mycompiler.mydomain.com ansible_user=<youruser> ansible_become_pass=<sudo-password>

Substitute mycompiler.mydomain.com with your hostname (ip addresses are allowed as well).

Also put your SSH user and password respectively in place of <youruser> and <sudo-password> (must be sudoer and non-root). These credentials are used during the Installation of dependencies step.

5. Create playbook file

Create a new playbook file playbook.yml on your local machine with the following contents:

# playbook.yml
- hosts: your_host_here
  roles:
    - openwisp.openwisp2-imagegenerator
  vars:
    openwisp2fw_source_dir: /home/user/openwisp2-firmware-source
    openwisp2fw_generator_dir: /home/user/openwisp2-firmware-generator
    openwisp2fw_bin_dir: /home/user/openwisp2-firmware-builds
    openwisp2fw_source_targets:
        - system: ar71xx
          subtarget: generic
          profile: Default
        - system: x86
          subtarget: generic
          profile: Generic
    openwisp2fw_organizations:
        - name: snakeoil # name of the org
          flavours: # supported flavours
            - standard
          luci_openwisp: # /etc/config/luci_openwisp
            # other config keys can be added freely
            username: "operator"
            # clear text password that will be encrypted in /etc/config/luci_openwisp
            password: "<CHANGE_ME>"
          openwisp: # /etc/config/openwisp
            # other config keys can be added freely
            url: "https://my-openwisp2-instance.com"
            shared_secret: "my-openwisp2-secret"
            unmanaged: "{{ openwisp2fw_default_unmanaged }}"
          # clear text password that will be encrypted in /etc/shadow
          root_password: "<CHANGE_ME>"

This playbook will let you compile firmware images for an organization named snakeoil using only the standard flavour (which includes a default OpenWRT 18.06 image with the standard OpenWISP2 modules) for two architectures, ar71xx and x86.

See the section Role Variables to know how to customize the available configurations.

At this stage your directory layout should look like the following:

.
├── hosts
└── playbook.yml

6. Run the playbook

Now is time to start the compilation of OpenWISP2 Firmware.

Launch the playbook from your local machine with:

ansible-playbook -i hosts playbook.yml -e "recompile=1 cores=4"

You can substitute cores=4 with the number of cores at your disposal.

When the playbook is done running you will find the images on the compilation server located in the directory specified in openwisp2fw_bin_dir, which in our example is /home/user/openwisp2-firmware-builds with a directory layout like the following:

/home/user/openwisp2-firmware-builds
├── snakeoil/                                      # (each org has its own dir)
├── snakeoil/2016-12-02-094316/ar71xx/standard/    # (contains ar71xx images for standard flavour)
├── snakeoil/2016-12-02-094316/x86/standard/       # (contains x86 images for standard flavour)
└── snakeoil/latest/                               # (latest is a symbolic link to the last compilation)

Now, if you followed this tutorial and everything worked out, you are ready to customize your configuration to suit your needs! Read on to find out how to accomplish this.

Role variables

There are many variables that can be customized if needed, take a look at the defaults for a comprehensive list.

Some of those variables are also explained in Organizations and Flavours.

Organizations

If you are working with OpenWISP, there are chances you may be compiling images for different groups of people: for-profit clients, no-profit organizations or any group of people that can be defined as an "organization".

Organizations can be defined freely in openwisp2fw_organizations.

For an example of how to do this, refer to the "example playbook.yml file".

If you need to add specific files in the filesystem tree of the images of each organization, see "Adding files for specific organizations".

Flavours

A flavour is a combination of packages that are included in an image.

You may want to create different flavours for your images, for example:

• standard: the most common use case
• minimal: an image for device which have little storage space available
• mesh: an image with packages that are needed for implementing a mesh network

By default only a standard flavour is available.

You can define your own flavours by setting openwisp2fw_image_flavours - take a look at the default variables to undetstand its structure.

Build process

The build process is composed of the following steps.

1. Installation of dependencies

tag: install

In this phase the operating system dependencies needed for the subsequent steps are installed or upgraded.

2. Compilation

tag: compile

The OpenWRT source is compiled in order to produce something called "Image Generator". The image generator is an archive that contains the precompiled packages and a special Makefile that will be used to generate the customized images for each organization.

The source is downloaded and compiled in the directory specified in openwisp2fw_source_dir.

3. Preparation of generators

tag: generator

During this step the image generators are extracted and prepared for building different images for different organizations, each organization can build images for different flavours (eg: full-featured, minimal, mesh, ecc);

The images are extracted and prepared in the directory specified in openwisp2fw_generator_dir.

4. Building of final images

tag: build

In this phase a series of images is produced.

Several images will be built for each architecture, organization and flavour. This can generate quite a lof of files, therefore use this power with caution: it's probably better to start with fewer options and add more cases as you go ahead.

For example, if you choose to use 2 architectures (ar71xx and x86), 2 organizations (eg: A and B) and 2 flavours (eg: standard and mini), you will get 8 groups of images:

• organization: A / flavour: standard / arch: ar71xx
• organization: A / flavour: standard / arch: x86
• organization: A / flavour: mini / arch: ar71xx
• organization: A / flavour: mini / arch: x86
• organization: B / flavour: standard / arch: ar71xx
• organization: B / flavour: standard / arch: x86
• organization: B / flavour: mini / arch: ar71xx
• organization: B / flavour: mini / arch: x86

The images will be created in the directory specified in openwisp2fw_bin_dir.

Adding files to images

You can add arbitrary files in every generated image by placing these files in a directory named files/ in your playbook directory.

Example:

.
├── hosts
├── playbook.yml
└── files/etc/profile

files/etc/profile will be added in every generated image.

Adding files for specific organizations

You can add files to images of specific organizations too.

Let's say you have an organization called snakeoil and you want to add a custom banner, you can accomplish this by creating the following directory structure:

.
├── hosts
├── playbook.yml
└── organizations/snakeoil/etc/banner

Since this step is one of the last steps performed before building the final images, you can use this feature to overwrite any file built automatically during the previous steps.

Extra parameters

You can pass the following extra parameters to ansible-playbook:

• recompile: wether to repeat the compilation step
• cores: number of cores to use during the compilation step
• orgs: comma separated list of organization names if you need to limit the generation of images to specific organiations

Examples

Recompile with 16 cores:

ansible-playbook -i hosts playbook.yml -e "recompile=1 cores=16"

Generate images only for organization foo:

ansible-playbook -i hosts playbook.yml -e "orgs=foo"

Generate images only for organizations foo and bar:

ansible-playbook -i hosts playbook.yml -e "orgs=foo,bar"

Run specific steps

Since each step in the process is tagged, you can run specific steps by using ansible tags.

Example 1, run only the preparation of generators:

ansible-playbook -i hosts playbook.yml -t generator

Example 2, run only the preparation of generators and build steps:

ansible-playbook -i hosts playbook.yml -t generator,build

Targets with no subtarget

This example shows how to fill openwisp2fw_source_targets in order to compile targets that do not specify a subtarget (eg: sunxi, ARMv8, QEMU):

openwisp2fw_source_targets:
    # Allwinner SOC, Lamobo R1
    - system: sunxi
      profile: DEVICE_sun7i-a20-lamobo-r1
    # QEMU ARM Virtual Image
    - system: armvirt
      profile: Default

Support

See OpenWISP Support Channels.