AGL Application Framework: A Quick Tutorial
Introduction
This document proposes a quick tutorial to demonstrate the major
functionalities of the AGL Application Framework.
For more complete information, please refer to the inline documentation
available in the main git repository:
https://gerrit.automotivelinux.org/gerrit/#/admin/projects/src/app-framework-main
For more information on AGL, please visit:
https://www.automotivelinux.org/
Sample applications
4 sample applications (.wgt files) are prebuilt and available at the following address:
https://github.com/iotbzh/afm-widget-examples
You can get them by cloning this git repository on your desktop (will be useful later in this tutorial):
git clone https://github.com/iotbzh/afm-widget-examples
Using the CLI tool
Setup Environment
Connect your AGL target board to the network and copy some sample widgets on it through SSH (set BOARDIP with your board IP address) :
cd afm-widget-examples
BOARDIP=1.2.3.4
scp *.wgt root@$BOARDIP:~/
Connect through SSH on the target board and check for Application Framework daemons:
$ ssh root@$BOARDIP
root@porter:~# ps -ef|grep bin/afm
afm 409 1 0 13:00 ? 00:00:00 /usr/bin/afm-system-daemon
root 505 499 0 13:01 ? 00:00:00 /usr/bin/afm-user-daemon
root 596 550 0 13:22 pts/0 00:00:00 grep afm
We can see that there are two daemons running:
- afm-system-daemon runs with a system user 'afm' and is responsible for installing/uninstalling packages
- afm-user-daemon runs as a user daemon (currently as root because it's the only real user on the target board) and is responsible for the whole life cycle of the applications running inside the user session.
The application framework has a tool running on the
Command Line Interface (CLI).
Using the afm-util command, you can install, uninstall, list, run, pause ... applications.
To begin, run 'afm-util help' to get a quick help on commands:
root@porter:~# afm-util help
usage: afm-util command [arg]
The commands are:
list
runnables list the runnable widgets installed
add wgt
install wgt install the wgt file
remove id
uninstall id remove the installed widget of id
info id
detail id print detail about the installed widget of id
ps
runners list the running instance
run id
start id start an instance of the widget of id
kill rid
terminate rid terminate the running instance rid
status rid
state rid get status of the running instance rid
Install an application
You can then install your first application:
root@porter:~# afm-util install /home/root/annex.wgt
{ "added": "webapps-annex@0.0" }
Let's install a second application:
root@porter:~# afm-util install /home/root/memory-match.wgt
{ "added": "webapps-memory-match@1.1" }
Note that usually, afm-util will return a JSON result, which is the common format for messages returned by the Application Framework daemons.
List installed applications
You can then list all installed applications:
root@porter:~# afm-util list
[ { "id": "webapps-annex@0.0", "version": "0.0.10", "width": 0, "height": 0, "name": "Annex", "description": "Reversi\/Othello", "shortname": "", "author": "Todd Brandt <todd.e.brandt@intel.com>" },
{ "id": "webapps-memory-match@1.1", "version": "1.1.7", "width": 0, "height": 0, "name": "MemoryMatch", "description": "Memory match", "shortname": "", "author": "Todd Brandt <todd.e.brandt@intel.com>" } ]
Here, we can see the two previously installed applications.
Get information about an application
Let's get some details about the first application:
root@porter:~# afm-util info webapps-annex@0.0
{ "id": "webapps-annex@0.0", "version": "0.0.10", "width": 0, "height": 0, "name": "Annex", "description": "Reversi\/Othello", "shortname": "", "author": "Todd Brandt <todd.e.brandt@intel.com>" }
Note: that AGL applications are mostly handled by afm-util through their IDs.
In our example, the application ID is 'webapps-annex@0.0'.
Start application
Let's start the first application Annex:
root@porter:~# afm-util start webapps-annex@0.0
1
As the application is a HTML5 game, you should then get a webview running with QML on the board display.
Security Context
The application has been started in the user session, with a dedicated security context, enforced by SMACK.
To illustrate this, we can take a look at the running processes and their respective SMACK labels:
root@porter:~# ps -efZ |grep webapps-annex | grep -v grep
User::App::webapps-annex root 716 491 0 13:19 ? 00:00:00 /usr/bin/afb-daemon --mode=local --readyfd=8 --alias=/icons /usr/share/afm/icons --port=12348 --rootdir=/usr/share/afm/applications/webapps-annex/0.0 --token=7D6D2F16 --sessiondir=/home/root/app-data/webapps-annex/.afb-daemon
User::App::webapps-annex root 717 491 0 13:19 ? 00:00:00 /usr/bin/qt5/qmlscene http://localhost:12348/index.html?token=7D6D2F16 /usr/bin/web-runtime-webkit.qml
In the previous result, we see that the application is composed of two processes:
- the application binder (afb-daemon)
- the application UI (qmlscene ...)
While most system processes run with the label 'System', we see that the
application runs with a specific SMACK label 'User::App::webapps-annex': this
label is used to force the application to follow
a Mandatory Access Control (MAC) scheme.
This means that those processes run in their own security context,
isolated from the rest of the system (and other applications).
Global security rules can then be applied to restrict access
to all other user or system resources.
Check running applications
To check for running applications, just run:
root@porter:~# afm-util ps
[ { "runid": 1, "state": "running", "id": "webapps-annex@0.0" } ]
The 'runid' is the application instance ID and is used as an argument for the subcommands controlling the application runtime state (kill/pause/resume/status)
Uninstall application
To uninstall an application, simply use its ID:
root@porter:~# afm-util uninstall webapps-annex@0.0
true
Then list the installed apps to confirm the removal:
root@porter:~# afm-util list
[ { "id": "webapps-memory-match@1.1", "version": "1.1.7", "width": 0, "height": 0, "name": "MemoryMatch", "description": "Memory match", "shortname": "", "author": "Todd Brandt <todd.e.brandt@intel.com>" } ]
afm-client: a sample HTML5 'Homescreen'
afm-client is a HTML5 UI that allows to install/uninstall applications as well as starting/pausing them as already demonstrated with afm-util.
The HTML5 UI is accessible remotely through this URL:
http://[board_ip]:1234/opa?token=132456789
Installing an application
By clicking on the 'Upload' button on the right,
you can send an application package (WGT file) and install it.
Select for example the file 'rabbit.wgt' that was cloned initially
from the git repository afm-widget-examples.
Then a popup requester ask for a confirmation:
'Upload Application rabbit.wgt ?'. Click on the 'Install' button.
You should then see some changes in the toolbar:
a new icon appeared, representing the freshly installed application.
Running an application
In the toolbar, click on the button representing the Rabbit application.
You'll get a popup asking to:
- start the application
- or get some info about it
- or uninstall it
Click on the 'start' item: the application starts and should be visible
as a webview on the target board display.
Note that at this point, we could also run the application remotely,
that is in the same browser as the Homescreen app.
By default, the application framework is configured
to run applications 'locally' on the board display.
Uninstalling an application
From the same popup menu, you can select 'uninstall'
to remove the application from the system.
As a consequence, the application icon should disappear from the toolbar.
afb-client: a template for Angular Applications
Another package 'afb-client' is also available for testing.
This is a sample HTML5 application demonstrating various basic
capabilities of the Binder daemon.
It can be used by developers as a template to start writing real AGL Applications.
This application is not available as WGT file yet and it should be started manually without any specific security context:
root@porter:~# /usr/bin/afb-daemon --port=1235 --token='' --sessiondir=/home/root/.afm-daemon --rootdir=/usr/share/agl/afb-client --alias=/icons:/usr/share/afm/icons
Then you can access it from a browser:
http://[board_ip]:1235/opa/?token=132456789
afb-client is a simple application to demonstrate the built-in capabilities of the binder daemon (handling sessions and security tokens, testing POSTs uploads...) and was used during the application framework development to validate the proposed features.