OpenWRT configuration agent for OpenWISP Controller
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README.rst

openwisp-config


OpenWRT configuration agent for the new OpenWISP 2 Controller.

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Install precompiled package

First run:

opkg update

Then install one of the latest builds:

opkg install <URL>

Where <URL> is the URL of the image that is suitable for your case (we suggest openssl or alternatively mbedtls).

For a list of the latest built images, take a look at downloads.openwisp.io/openwisp-config/.

If you need to compile the package yourself, see Compiling openwisp-config and Compiling a custom OpenWRT image.

Once installed openwisp-config needs to be configured (see Configuration options) and then started with:

/etc/init.d/openwisp_config start

To ensure the agent is working correctly find out how to perform debugging in the Debugging section.

Configuration options

UCI configuration options must go in /etc/config/openwisp.

  • url: url of controller, eg: https://controller.openwisp.org
  • interval: time in seconds between checks for changes to the configuration, defaults to 120
  • verify_ssl: whether SSL verification must be performed or not, defaults to 1
  • shared_secret: shared secret, needed for Automatic registration
  • consistent_key: whether Consistent key generation is enabled or not, defaults to 1
  • merge_config: whether Merge configuration is enabled or not, defaults to 1
  • test_config: whether a new configuration must be tested before being considered applied, defaults to 1
  • test_script: custom test script, read more about this feature in Configuration test
  • uuid: unique identifier of the router configuration in the controller application
  • key: key required to download the configuration
  • unmanaged: list of config sections which won't be overwritten, see Unmanaged Configurations
  • capath: value passed to curl --capath argument, by default is empty; see also curl capath argument
  • cacert: value passed to curl --cacert argument, by default is empty; see also curl cacert argument
  • connect_timeout: value passed to curl --connect-timeout argument, defaults to 15; see curl connect-timeout argument
  • max_time: value passed to curl --max-time argument, defaults to 30; see curl connect-timeout argument
  • mac_interface: the interface from which the MAC address is taken when performing automatic registration, defaults to eth0
  • management_interface: management interface name (both openwrt UCI names and linux interface names are supported), it's used to collect the management interface ip address
  • pre_reload_hook: path to custom executable script, see pre-reload-hook
  • post_reload_hook: path to custom executable script, see post-reload-hook

Automatic registration

When the agent starts, if both uuid and key are not defined, it will consider the router to be unregistered and it will attempt to perform an automatic registration.

The automatic registration is performed only if shared_secret is correctly set.

The device will choose as name one of its mac addresses, unless its hostname is not OpenWrt, in the latter case it will simply register itself with the current hostname.

When the registration is completed, the agent will automatically set uuid and key in /etc/config/openwisp.

To enable this feature by default on your firmware images, follow the procedure described in Compiling a custom OpenWRT image.

Consistent key generation

When using Automatic registration, this feature allows devices to keep the same configuration even if reset or reflashed.

The key is generated consistently with an operation like md5sum(mac_address + shared_secret); this allows the controller application to recognize that an existing device is registering itself again.

The mac_interface configuration key specifies which interface is used to calculate the mac address, this setting defaults to eth0. If no eth0 interface exists, the first non-loopback, non-bridge and non-tap interface is used. You won't need to change this setting often, but if you do, ensure you choose a physical interface which has constant mac address.

The "Consistent key generation" feature is enabled by default, but must be enabled also in the controller application in order to work.

Merge configuration

By default the remote configuration is merged with the local one. This has several advantages:

  • less bolierplate configuration stored in the remote controller
  • local users can change local configurations without fear of losing their changes

It is possible to turn this feature off by setting merge_config to 0 in /etc/config/openwisp.

Configuration test

When a new configuration is downloaded, the agent will first backup the current running configuration, then it will try to apply the new one and perform a basic test, which consists in trying to contact the controller again;

If the test succeeds, the configuration is considered applied and the backup is deleted.

If the test fails, the backup is restored and the agent will log the failure via syslog (see Debugging for more information on auditing logs).

Disable testing

To disable this feature, set the test_config option to 0, then reload/restart openwisp_config.

Define custom tests

If the default test does not satisfy your needs, you can define your own tests in an executable script and indicate the path to this script in the test_script config option.

If the exit code of the executable script is higher than 0 the test will be considered failed.

Unmanaged Configurations

In some cases it could be necessary to ensure that some configuration sections won't be overwritten by the controller.

These settings are called "unmanaged", in the sense that they are not managed remotely. In the default configuration of openwisp_config there are no unmanaged settings.

Example unmanaged settings:

config controller 'http'
        ...
        list unmanaged 'system.@led'
        list unmanaged 'network.loopback'
        list unmanaged 'network.@switch'
        list unmanaged 'network.@switch_vlan'
        ...

Note the lines with the @ sign; this syntax means any UCI section of the specified type will be unmanaged.

In the previous example, the loopback interface, all led settings, all switch and switch_vlan directives will never be overwritten by the remote configuration and will only be editable via SSH or via the web interface.

Hooks

Below are described the available hooks in openwisp-config.

pre-reload-hook

Defaults to /etc/openwisp/pre-reload-hook; the hook is not called if the path does not point to an executable script file.

This hook is called each time openwisp-config applies a configuration, but before services are reloaded, more precisely in these situations:

  • after a new remote configuration is downloaded and applied
  • after a configuration test failed (see Configuration test) and a previous backup is restored

You can use this hook to perform custom actions before services are reloaded, eg: to perform auto-configuration with LibreMesh.

Example configuration:

config controller 'http'
        ...
        option pre_reload_hook '/usr/sbin/my-pre-reload-hook'
        ...

Complete example:

# set hook in configuration
uci set openwisp.http.pre_reload_hook='/usr/sbin/my-pre-reload-hook'
uci commit openwisp
# create hook script
cat <<EOF > /usr/sbin/my-pre-reload-hook
#!/bin/sh
# put your custom operations here
EOF
# make script executable
chmod +x /usr/sbin/my-pre-reload-hook
# reload openwisp_config by using procd's convenient utility
reload_config

post-reload-hook

Defaults to /etc/openwisp/post-reload-hook; the hook is not called if the path does not point to an executable script file.

Same as pre_reload_hook but with the difference that this hook is called after the configuration services have been reloaded.

Compiling openwisp-config

There are 4 variants of openwisp-config:

  • openwisp-config-openssl: depends on ca-certificates and libopenssl
  • openwisp-config-mbedtls: depends on ca-certificates and libmbedtls
  • openwisp-config-cyassl: depends on ca-certificates and libcyassl
  • openwisp-config-nossl: doesn't depend on any SSL library and doesn't install trusted CA certificates

The following procedure illustrates how to compile all the openwisp-config variants and their dependencies:

git clone https://github.com/openwrt/openwrt.git openwrt
cd openwrt
git checkout openwrt-18.06

# configure feeds
echo "src-git openwisp https://github.com/openwisp/openwisp-config.git" > feeds.conf
cat feeds.conf.default >> feeds.conf
./scripts/feeds update -a
./scripts/feeds install -a
# any arch/target is fine because the package is architecture indipendent
arch="ar71xx"
echo "CONFIG_TARGET_$arch=y" > .config;
echo "CONFIG_PACKAGE_openwisp-config-openssl=y" >> .config
echo "CONFIG_PACKAGE_openwisp-config-mbedtls=y" >> .config
echo "CONFIG_PACKAGE_openwisp-config-cyassl=y" >> .config
echo "CONFIG_PACKAGE_openwisp-config-nossl=y" >> .config
make defconfig
make tools/install
make toolchain/install
make package/openwisp-config/compile

Alternatively, you can configure your build interactively with make menuconfig, in this case you will need to select the openwisp-config variant by going to Administration > openwisp:

git clone https://github.com/openwrt/openwrt.git openwrt
cd openwrt
git checkout openwrt-18.06

# configure feeds
echo "src-git openwisp https://github.com/openwisp/openwisp-config.git" > feeds.conf
cat feeds.conf.default >> feeds.conf
./scripts/feeds update -a
./scripts/feeds install -a
make menuconfig
# go to Administration > openwisp and select the variant you need interactively
make -j1 V=s

Compiling a custom OpenWRT image

If you are managing many devices and customizing your openwisp-config configuration by hand on each new device, you should switch to using a custom OpenWRT firmware image that includes openwisp-config and its precompiled configuration file, this strategy has a few important benefits:

  • you can save yourself the effort of installing and configuring openwisp-config on each device
  • you can enable Automatic registration by setting shared_secret, hence saving extra time and effort to register each device on the controller app
  • if you happen to reset the firmware to initial settings, these precompiled settings will be restored as well

The following procedure illustrates how to compile a custom OpenWRT 18.06.1 image with a precompiled minimal /etc/config/openwisp configuration file:

git clone https://github.com/openwrt/openwrt.git openwrt
cd openwrt
git checkout openwrt-18.06

# include precompiled file
mkdir -p files/etc/config
cat <<EOF > files/etc/config/openwisp
config controller 'http'
    # change the values of the following 2 options
    option url 'https://openwisp2.mydomain.com'
    option shared_secret 'mysharedsecret'
EOF

# configure feeds
echo "src-git openwisp https://github.com/openwisp/openwisp-config.git" > feeds.conf
cat feeds.conf.default >> feeds.conf
./scripts/feeds update -a
./scripts/feeds install -a
# replace with your desired arch target
arch="ar71xx"
echo "CONFIG_TARGET_$arch=y" > .config
echo "CONFIG_PACKAGE_openwisp-config-openssl=y" >> .config
echo "CONFIG_LIBCURL_OPENSSL=y" >> .config
make defconfig
# compile with verbose output
make -j1 V=s

Automate compilation for different organizations

If you are working with OpenWISP, there are chances you may be compiling several images for different organizations (clients or non-profit communities) and use cases (full featured, mesh, 4G, etc).

Doing this by hand without tracking your changes can lead you into a very disorganized and messy situation.

To alleviate this pain you can use ansible-openwisp2-imagegenerator.

Debugging

Debugging openwisp-config can be easily done by using the logread command:

logread

Use grep to filter out any other log message:

logread | grep openwisp

If you are in doubt openwisp-config is running at all, you can check with:

ps | grep openwisp

You should see something like:

3800 root      1200 S    {openwisp_config} /bin/sh /usr/sbin/openwisp_config --url https://openwisp2.mydomain.com --verify-ssl 1 --consistent-key 1 ...

You can inspect the version of openwisp-config currently installed with:

openwisp_config --version

Run tests

To run the unit tests, you must install the required dependencies first; to do this, you can take a look at the install-dev.sh script.

You can run all the unit tests by launching the dedicated script:

./runtests

Alternatively, you can run specifc tests, eg:

cd openwisp-config/tests/
lua test_utils.lua -v

Contributing

Please read the OpenWISP contributing guidelines.

Changelog

See CHANGELOG.

License

See LICENSE.

Support

See OpenWISP Support Channels.