Daemons of the application framework

Introduction

The application framework of redpesk provides two services running in background as daemons. They ensure that operations use correctly the security framework and that applications are executed in the correct security context.

• afmpkg-installerd: this daemon installs and removes applications. It is automatically called when dnf installs or removes applications. It automatically stops after an inactivity period.

• afm-system-daemon: this daemon handles life cycle of installed application: listing, starting, stopping. It can be accessed through the command line utility afm-util.

afm-system-daemon

The daemon afm-system-daemon is accessible through redpesk micro-service architecture using either the binder afb-binder, the client library libafbcli or the programs afb-client and afm-util.

It is installed as a systemd service and started automatically on need.

It can also be started, restarted, stopped, checked using systemctl as below:

$ systemctl status afm-system-daemon

List of applications

At start afm-system-daemon scans the directories containing applications and load in memory a list of available applications accessible by current user.

afm-system-daemon provides the data it collects about applications to its clients. Clients may either request the full list of available applications or a more specific information about a given application.

Starting applications

afm-system-daemon starts application by using systemd. Systemd builds a secure environment for the application before starting it.

Once launched, running instances of application receive a runid that identify them. On previous versions, the runid had a special meaning. The current version uses the linux PID of the launched process as runid.

List of running applications

afm-system-daemon manages the list of applications that it launched.

When owning the right permissions, a client can get the list of running instances and details about a specific running instance. It can also terminate a given application.

afmpkg-installerd

The daemon afmpkg-installerd is activated by the dnf’s plugin named redpesk when it detects that the installed or removed package is an afmpkg.

After being used, if afmpkg-installerd is not used for 5 minutes, it automatically stops.

Installing applications

afmpkg-installerd reads the metadata of the installed package and check it.

When metadata are wrong, the installation is cancelled.

Otherwise, when metadata are valid, afmpkg-installerd contacts the security manager to setup the system security for the installed application.

After installing or removing an application, afmpkg-installerd sends to afm-system-daemon a signal telling it to update its applications database.

Removing applications

afmpkg-installerd contacts the security manager to cleanup the security rules for the removed application and to remove their security setup.