From 4a1409460a7c0a5d26fe10b5f84368b3cb8b8b5a Mon Sep 17 00:00:00 2001 From: José Bollo Date: Wed, 26 Oct 2016 18:24:13 +0200 Subject: doc: switch to mkdocs MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: José Bollo --- docs/afm-user-daemon.md | 696 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 696 insertions(+) create mode 100644 docs/afm-user-daemon.md (limited to 'docs/afm-user-daemon.md') diff --git a/docs/afm-user-daemon.md b/docs/afm-user-daemon.md new file mode 100644 index 0000000..f1ce7f8 --- /dev/null +++ b/docs/afm-user-daemon.md @@ -0,0 +1,696 @@ + +The afm-user-daemon +=================== + +Foreword +-------- + +This document describes application framework user daemon fundamentals. +FCF (Fully Conform to Specification) implementation is still under development. +It may happen that current implementation somehow diverges with specifications. + + +Introduction +------------ + +The daemon **afm-user-daemon** is in charge of handling +applications on behalf of a user. Its main tasks are: + + - enumerate applications that end user can run + and keep this list available on demand + + - start applications on behalf of end user, set user running + environment, set user security context + + - list current runnable or running applications + + - stop (aka pause), continue (aka resume), terminate + a running instance of a given application + + - transfer requests for installation/uninstallation + of applications to the corresponding system daemon + **afm-system-daemon** + +The **afm-user-daemon** takes its orders from the session +instance of D-Bus. + +The figure below summarizes the situation of **afm-user-daemon** in the system. + + +------------------------------------------------------------+ + | User | + | +---------------------+ | + | +---------------------+ | Smack isolated | | + | | D-Bus session + | APPLICATIONS | | + | +----------+----------+ +---------+-----------+ | + | | | | + | | | | + | +----------+--------------------------+-----------+ | + | | | | + | | afm-user-daemon | | + | | | | + | +----------+----------------------+----------+----+ | + | | | : | + | | | : | + :================|======================|==========:=========: + | | | : | + | +----------+----------+ +-----+-----+ : | + | | D-Bus system +-----+ CYNARA | : | + | +----------+----------+ +-----+-----+ : | + | | | : | + | +----------+---------+ +-------+----------+----+ | + | | afm-system-daemon +----+ SECURITY-MANAGER | | + | +--------------------+ +-----------------------+ | + | | + | System | + +------------------------------------------------------------+ + + +Tasks of **afm-user-daemon** +---------------------------- + +### Maintaining list of applications ### + +At start **afm-user-daemon** scans the directories containing +applications and load in memory a list of avaliable applications +accessible by current user. + +When **afm-system-daemon** installs or removes an application. +On success it sends the signal *org.AGL.afm.system.changed*. +When receiving such a signal, **afm-user-daemon** rebuilds its +applications list. + +**afm-user-daemon** provides the data it collects about +applications to its clients. Clients may either request the full list +of avaliable applications or a more specific information about a +given application. + +### Launching application ### + +**afm-user-daemon** launches application. Its builds a secure +environment for the application before starting it within a +secured environment. + +Different kind of applications can be launched. + +This is set using a configuration file that describes +how to launch an application of a given kind within a given +mode. + +There is two launching modes: local or remote. + +Launching an application locally means that +the application and its binder are launched together. + +Launching application remotely translates in only launching +the application binder. The UI by itself has to be activated +remotely by the requested (ie: HTML5 homescreen in a browser) + +Once launched, running instances of application receive +a runid that identify them. + +### Managing instances of running applications ### + +**afm-user-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 terminates, stops or +continues a given application. + +### Installing and uninstalling applications ### + +If the client own the right permissions, +**afm-user-daemon** delegates that task +to **afm-system-daemon**. + + +Starting **afm-user-daemon** +----------------------------- + +**afm-user-daemon** is launched as a **systemd** service +attached to user sessions. Normally, the service file is +located at /usr/lib/systemd/user/afm-user-daemon.service. + +The options for launching **afm-user-daemon** are: + + -a + --application directory + + Includes the given application directory to + the database base of applications. + + Can be repeated. + + -r + --root directory + + Includes root application directory or directories when + passing multiple rootdir to + applications database. + + Note that default root directory for + applications is always added. In current version + /usr/share/afm/applications is used as default. + + -m + --mode (local|remote) + + Set the default launch mode. + The default value is 'local' + + -d + --daemon + + Daemonizes the process. It is not needed by sytemd. + + -q + --quiet + + Reduces the verbosity (can be repeated). + + -v + --verbose + + Increases the verbosity (can be repeated). + + -h + --help + + Prints a short help. + + +Launcher Configuration +----------------------------- + +It contains rules for launching applications. +When **afm-user-daemon** has to launch an application, +it looks for launch mode (local or remote), as well as +for the type of application describe in ***config.xml*** +widget configuration file. + +This tuple mode+type allows to select the adequate rule. + +Configuration file is **/etc/afm/afm-launch.conf**. + +It contains sections and rules. It can also contain comments +and empty lines to improve readability. + +The separators are space and tabulation, any other character +should have a meaning. + +The format is line oriented. +The new line character separate the lines. + +Lines having only separators are blank lines and ignored. +Line having character #(sharp) at first position are comment +lines and ignored. + +Lines not starting with a separator are different +from lines starting with a separator character. + +The grammar of the configuration file is defined below: + + CONF: *COMMENT *SECTION + + SECTION: MODE *RULE + + RULE: +TYPE VECTOR ?VECTOR + + MODE: 'mode' +SEP ('local' | 'remote') *SEP EOL + + TYPE: DATA *SEP EOL + + VECTOR: +SEP DATA *(+SEP NDATA) *SEP EOL + + DATA: CHAR *NCHAR + NDATA: +NCHAR + + EOL: NL *COMMENT + COMMENT: *SEP CMT *(SEP | NCHAR) NL + + NL: '\x0a' + SEP: '\x20' | '\x09' + CMT: '#' + CHAR: '\x00'..'\x08' | '\x0b'..'\x1f' | '\x21' | '\x22' | '\x24'..'\xff' + NCHAR: CMT | CHAR + +Here is a sample of configuration file for defining how +to launch an application of types *application/x-executable*, +*text/x-shellscript* and *text/html* in local mode: + + mode local + + application/x-executable + text/x-shellscript + %r/%c + + text/html + /usr/bin/afb-daemon --mode=local --readyfd=%R --alias=/icons:%I --port=%P --rootdir=%r --token=%S --sessiondir=%D/.afb-daemon + /usr/bin/web-runtime http://localhost:%P/%c?token=%S + +This shows that: + + - within a section, several rules can be defined + - within a rule, several types can be defined + - within a rule, one or two vectors can be defined + - vectors are using %substitution + - launched binaries must be defined with their full path + +### mode local + +Within this mode, the launchers have either one or two description vectors. +All of those vectors are treated as programs +and are executed with 'execve' system call. + +The first vector is the leader vector and it defines the process +group. The second vector (if any) is attached to the group +defined by this first vector. + +### mode remote + +Within this mode, the launchers have either one or two vectors +describing them. + +The first vector is process as a program and is executed with +system call 'execve'. + +The second vector (if any) defines a text that is returned +to the caller. This mechanism can be used to return a uri +for remote UI to connect on the newly launched application. + +The daemon ***afm-user-daemon*** allocates a port for each +new remote application. +The current implementation port allocation is incremental. +A smarter (cacheable and discoverable) allocation should be defined. + +### %substitutions + +Vectors can include sequences of 2 characters that have a special +meaning. These sequences are named *%substitution* because their +first character is the percent sign (%) and because each occurrence +of the sequence is replaced, at launch time, by the value associated +to sequences. + +Here is the list of *%substitutions*: + + - ***%%***: %. + + This simply emits the percent sign % + + - ***%a***: appid + + Holds application Id of launched application. + + Defined by the attribute **id** of the element **** + of **config.xml**. + + - ***%b***: bindings + + In the future should represent the list of bindings and bindings directory separated by ','. + Warning: not supported in current version. + + - ***%c***: content + + The file within the widget directory that is the entry point. + + For HTML applications, it represents the relative path to main + page (aka index.html). + + Defined by attribute **src** of the element **** within **config.xml**. + + - ***%D***: datadir + + Path of the directory where the application runs (cwd) + and stores its data. + + It is equal to %h/%a. + + - ***%H***: height + + Requested height for the widget. + + Defined by the attribute **height** of the element **** + of **config.xml**. + + - ***%h***: homedir + + Path of the home directory for all applications. + + It is generally equal to $HOME/app-data + + - ***%I***: icondir + + Path of the directory were the icons of the applications can be found. + + - ***%m***: mime-type + + Mime type of the launched application. + + Defined by the attribute **type** of the element **** + of **config.xml**. + + - ***%n***: name + + Name of the application as defined by the content of the + element **** of **config.xml**. + + - ***%P***: port + + A port to use. It is currently a kind of random port. The precise + model is to be defined later. + + - ***%R***: readyfd + + Number of file descriptor to use for signaling + readiness of launched process. + + - ***%r***: rootdir + + Path of directory containing the widget and its data. + + - ***%S***: secret + + An hexadecimal number that can be used to initialize pairing of client + and application binder. + + - ***%W***: width + + Requested width for the widget. + + Defined by the attribute **width** of the element **** + of **config.xml**. + + +The D-Bus interface +------------------- + +### Overview of the dbus interface + +***afm-user-daemon*** takes its orders from the session instance +of D-Bus. D-Bus is nice to use in this context because it allows +discovery and signaling. + +The dbus session is by default addressed by environment +variable ***DBUS_SESSION_BUS_ADDRESS***. Using **systemd** +variable *DBUS_SESSION_BUS_ADDRESS* is automatically set for +user sessions. + +The **afm-user-daemon** is listening on destination name +***org.AGL.afm.user*** at object path ***/org/AGL/afm/user*** +on interface ***org.AGL.afm.user*** for following members: + ***runnables***, ***detail***, ***start***, ***terminate***, +***stop***, ***continue***, ***runners***, ***state***, +***install*** and ***uninstall***. + +D-Bus is mainly used for signaling and discovery. Its optimized +typed protocol is not used except for transmission of standalone strings. + +Clients and Services are using JSON serialisation to exchange data. + +The D-Bus interface is defined by: + + * DESTINATION: **org.AGL.afm.user** + + * PATH: **/org/AGL/afm/user** + + * INTERFACE: **org.AGL.afm.user** + +The signature of any member of the interface is ***string -> string*** +for ***JSON -> JSON***. + +This is the normal case. In case of error, the current implementation +returns a dbus error as a string. + +Here an example using *dbus-send* to query data on +installed applications. + + dbus-send --session --print-reply \ + --dest=org.AGL.afm.user \ + /org/AGL/afm/user \ + org.AGL.afm.user.runnables string:true + +### Using ***afm-util*** + +The command line tool ***afm-util*** uses dbus-send to send +orders to **afm-user-daemon**. This small scripts allows to +send command to ***afm-user-daemon*** either interactively +at shell prompt or scriptically. + +The syntax is simple: it accept a command and when requires attached arguments. + +Here is the summary of ***afm-util***: + + - **afm-util runnables **: + + list the runnable widgets installed + + - **afm-util install wgt **: + + install the wgt file + + - **afm-util uninstall id **: + + remove the installed widget of id + + - **afm-util detail id **: + + print detail about the installed widget of id + + - **afm-util runners **: + + list the running instance + + - **afm-util start id **: + + start an instance of the widget of id + + - **afm-util terminate rid **: + + terminate the running instance rid + + - **afm-util stop rid **: + + stop the running instance rid + + - **afm-util continue rid **: + + continue the previously rid + + - **afm-util state rid **: + + get status of the running instance rid + + +Here is how to list applications using ***afm-util***: + + afm-util runnables + +--- + +### The protocol over D-Bus + +Recall: + + * **DESTINATION**: org.AGL.afm.user + + * **PATH**: /org/AGL/afm/user + + * **INTERFACE**: org.AGL.afm.user + +--- + +#### Method org.AGL.afm.user.detail + +**Description**: Get details about an application from its id. + +**Input**: the id of the application as below. + +Either just a string: + + "appli@x.y" + +Or an object having the field "id" of type string: + + {"id":"appli@x.y"} + +**Output**: A JSON object describing the application containing +the fields described below. + + { + "id": string, the application id (id@version) + "version": string, the version of the application + "width": integer, requested width of the application + "height": integer, resqueted height of the application + "name": string, the name of the application + "description": string, the description of the application + "shortname": string, the short name of the application + "author": string, the author of the application + } + +--- + +#### Method org.AGL.afm.user.runnables + +**Description**: Get the list of applications that can be run. + +**Input**: any valid json entry, can be anything except null. + +**output**: An array of description of the runnable applications. +Each item of the array contains an object containing the detail of +an application as described above for the method +*org.AGL.afm.user.detail*. + +--- + +#### Method org.AGL.afm.user.install + +**Description**: Install an application from its widget file. + +If an application of the same *id* and *version* exists, it is not +reinstalled except when *force=true*. + +Applications are installed in the subdirectories of the common directory +reserved for applications. +If *root* is specified, the application is installed under +sub-directories of defined *root*. + +Note that this methods is a simple accessor to the method +***org.AGL.afm.system.install*** of ***afm-system-daemon***. + +After the installation and before returning to the sender, +***afm-user-daemon*** sends the signal ***org.AGL.afm.user.changed***. + +**Input**: The *path* of widget file to be installed. Optionally, +a flag to *force* reinstallation and/or a *root* directory. + +Simple form a simple string containing the absolute widget path: + + "/a/path/driving/to/the/widget" + +Or an object: + + { + "wgt": "/a/path/to/the/widget", + "force": false, + "root": "/a/path/to/the/root" + } + +"wgt" and "root" MUST be absolute paths. + +**output**: An object containing field "added" to use as application ID. + + {"added":"appli@x.y"} + +--- + +#### Method org.AGL.afm.user.uninstall + +**Description**: Uninstall an application from its id. + + +Note that this methods is a simple accessor to +***org.AGL.afm.system.uninstall*** method from ***afm-system-daemon***. + +After the uninstallation and before returning to the sender, +***afm-user-daemon*** sends the signal ***org.AGL.afm.user.changed***. + +**Input**: the *id* of the application and, optionally, the path to +application *root*. + +Either a string: + + "appli@x.y" + +Or an object: + + { + "id": "appli@x.y", + "root": "/a/path/to/the/root" + } + +**output**: the value 'true'. + +--- + +#### Method org.AGL.afm.user.start + +**Description**: + +**Input**: the *id* of the application and, optionally, the +start *mode* as below. + +Either just a string: + + "appli@x.y" + +Or an object containing field "id" of type string and +optionally a field mode: + + {"id":"appli@x.y","mode":"local"} + +The field "mode" is a string equal to either "local" or "remote". + +**output**: The *runid* of the application launched. *runid* is an integer. + +--- + +#### Method org.AGL.afm.user.terminate + +**Description**: Terminates the application attached to *runid*. + +**Input**: The *runid* (an integer) of running instance to terminate. + +**output**: the value 'true'. + +--- + +#### Method org.AGL.afm.user.stop + +**Description**: Stops the application attached to *runid* until terminate or continue. + +**Input**: The *runid* (integer) of the running instance to stop. + +**output**: the value 'true'. + +--- + +#### Method org.AGL.afm.user.continue + +**Description**: Continues the application attached to *runid* previously stopped. + +**Input**: The *runid* (integer) of the running instance to continue. + +**output**: the value 'true'. + +--- + +#### Method org.AGL.afm.user.state + +**Description**: Get informations about a running instance of *runid*. + +**Input**: The *runid* (integer) of the running instance inspected. + +**output**: An object describing instance state. It contains: +the runid (integer), the id of the running application (string), +the state of the application (string either: "starting", "running", "stopped"). + +Example of returned state: + + { + "runid": 2, + "state": "running", + "id": "appli@x.y" + } + +--- + +#### Method org.AGL.afm.user.runners + +**Description**: Get the list of currently running instances. + +**Input**: anything. + +**output**: An array of states, one per running instance, as returned by +the methodd ***org.AGL.afm.user.state***. + -- cgit 1.2.3-korg