--- /dev/null
+
+Overview of AFB-DAEMON
+======================
+
+Roles of afb-daemon
+-------------------
+
+The name **afb-daemon** stands for *Application
+Framework Binder Daemon*. That is why afb-daemon
+is also named ***the binder***.
+
+**Afb-daemon** is in charge to bind one instance of
+an application to the AGL framework and AGL system.
+
+On the following figure, you can use a typical use
+of afb-daemon:
+
+<h4><a id="binder-fig-basis">Figure: binder afb-daemon, basis</a></h4>
+
+![binder-basis][binder-basis]
+
+The application and its companion binder run in secured and isolated
+environment set for them. Applications are intended to access to AGL
+system through the binder.
+
+The binder afb-daemon serves multiple purposes:
+
+1. It acts as a gateway for the application to access the system;
+
+2. It acts as an HTTP server for serving files to HTML5 applications;
+
+3. It allows HTML5 applications to have native extensions subject
+to security enforcement for accessing hardware resources or
+for speeding parts of algorithm.
+
+Use cases of the binder afb-daemon
+----------------------------------
+
+This section tries to give a better understanding of the binder
+usage through several use cases.
+
+### Remotely running application
+
+One of the most interesting aspect of using the binder afb-daemon
+is the ability to run applications remotely. This feature is
+possible because the binder afb-daemon implements native web
+protocols.
+
+So the [figure binder, basis](#binder-fig-basis) would become
+when the application is run remotely:
+
+<h4><a id="binder-fig-remote">Figure: binder afb-daemon and remotely running application</a></h4>
+
+
+### Adding native features to HTML5/QML applications
+
+Applications can provide with their packaged delivery a binding.
+That binding will be instantiated for each application instance.
+The methods of the binding will be accessible by applications and
+will be executed within the security context.
+
+### Offering services to the system
+
+It is possible to run the binder afb-daemon as a daemon that provides the
+API of its bindings.
+
+This will be used for:
+
+1. offering common APIs
+
+2. provide application's services (services provided as application)
+
+In that case, the figure showing the whole aspects is
+
+<h4><a id="binder-fig-remote">Figure: binder afb-daemon for services</a></h4>
+
+![afb-for-services][afb-for-services]
+
+For this case, the binder afb-daemon takes care to attribute one single session
+context to each client instance. It allows bindings to store and retrieve data
+associated to each of its client.
+
+The bindings of the binder afb-daemon
+------------------------------------
+
+The binder can instantiate bindings. The primary use of bindings
+is to add native methods that can be accessed by applications
+written with any language through web technologies ala JSON RPC.
+
+This simple idea is declined to serves multiple purposes:
+
+1. add native feature to applications
+
+2. add common API available by any applications
+
+3. provide customers services
+
+A specific document explains how to write an afb-daemon binder binding:
+[HOWTO WRITE a BINDING for AFB-DAEMON](afb-bindings-writing.html)
+
+
+Launching the binder afb-daemon
+-------------------------------
+
+The launch options for binder **afb-daemon** are:
+
+ --help
+
+ Prints help with available options
+
+ --version
+
+ Display version and copyright
+
+ --verbose
+
+ Increases the verbosity, can be repeated
+
+ --quiet
+
+ Decreases the verbosity, can be repeated
+
+ --port=xxxx
+
+ HTTP listening TCP port [default 1234]
+
+ --workdir=xxxx
+
+ Directory where the daemon must run [default: $PWD if defined
+ or the current working directory]
+
+ --uploaddir=xxxx
+
+ Directory where uploaded files are temporarily stored [default: workdir]
+
+ --rootdir=xxxx
+
+ Root directory of the application to serve [default: workdir]
+
+ --roothttp=xxxx
+
+ Directory of HTTP served files. If not set, files are not served
+ but apis are still accessibles.
+
+ --rootbase=xxxx
+
+ Angular Base Root URL [default /opa]
+
+ This is used for any application of kind OPA (one page application).
+ When set, any missing document whose url has the form /opa/zzz
+ is translated to /opa/#!zzz
+
+ --rootapi=xxxx
+
+ HTML Root API URL [default /api]
+
+ The bindings are available within that url.
+
+ --alias=xxxx
+
+ Maps a path located anywhere in the file system to the
+ a subdirectory. The syntax for mapping a PATH to the
+ subdirectory NAME is: --alias=/NAME:PATH.
+
+ Example: --alias=/icons:/usr/share/icons maps the
+ content of /usr/share/icons within the subpath /icons.
+
+ This option can be repeated.
+
+ --no-httpd
+
+ Tells to not start the HTTP server.
+
+ --apitimeout=xxxx
+
+ binding API timeout in seconds [default 20]
+
+ Defines how many seconds maximum a method is allowed to run.
+ 0 means no limit.
+
+ --cntxtimeout=xxxx
+
+ Client Session Timeout in seconds [default 3600]
+
+ --cache-eol=xxxx
+
+ Client cache end of live [default 100000 that is 27,7 hours]
+
+ --session-max=xxxx
+
+ Maximum count of simultaneous sessions [default 10]
+
+ --ldpaths=xxxx
+
+ Load bindings from given paths separated by colons
+ as for dir1:dir2:binding1.so:... [default = $libdir/afb]
+
+ You can mix path to directories and to bindings.
+ The sub-directories of the given directories are searched
+ recursively.
+
+ The bindings are the files terminated by '.so' (the extension
+ so denotes shared object) that contain the public entry symbol.
+
+ --binding=xxxx
+
+ Load the binding of given path.
+
+ --token=xxxx
+
+ Initial Secret token to authenticate.
+
+ If not set, no client can authenticate.
+
+ If set to the empty string, then any initial token is accepted.
+
+ --random-token
+
+ Generate a random starting token. See option --exec.
+
+ --mode=xxxx
+
+ Set the mode: either local, remote or global.
+
+ The mode indicate if the application is run locally on the host
+ or remotely through network.
+
+ --readyfd=xxxx
+
+ Set the #fd to signal when ready
+
+ If set, the binder afb-daemon will write "READY=1\n" on the file
+ descriptor whose number if given (/proc/self/fd/xxx).
+
+ --dbus-client=xxxx
+
+ Transparent binding to a binder afb-daemon service through dbus.
+
+ It creates an API of name xxxx that is implemented remotely
+ and queried via DBUS.
+
+ --dbus-server=xxxx
+
+ Provides a binder afb-daemon service through dbus.
+
+ The name xxxx must be the name of an API defined by a binding.
+ This API is exported through DBUS.
+
+ --ws-client=xxxx
+
+ Transparent binding to a binder afb-daemon service through a WebSocket.
+
+ The value of xxxx is either a unix naming socket, of the form "unix:path/api",
+ or an internet socket, of the form "host:port/api".
+
+ --ws-server=xxxx
+
+ Provides a binder afb-daemon service through WebSocket.
+
+ The value of xxxx is either a unix naming socket, of the form "unix:path/api",
+ or an internet socket, of the form "host:port/api".
+
+ --foreground
+
+ Get all in foreground mode (default)
+
+ --daemon
+
+ Get all in background mode
+
+ --no-httpd
+
+ Forbids HTTP serve
+
+ --exec
+
+ Must be the last option for afb-daemon. The remaining
+ arguments define a command that afb-daemon will launch.
+ The sequences @p, @t and @@ of the arguments are replaced
+ with the port, the token and @.
+
+ --tracereq=xxxx
+
+ Trace the processing of requests in the log file.
+
+ Valid values are 'no' (default), 'common', 'extra' or 'all'.
+
+
+
+
+
+Future development of afb-daemon
+--------------------------------
+
+- The binder afb-daemon would launch the applications directly.
+
+- The current setting of mode (local/remote/global) might be reworked to a
+mechanism for querying configuration variables.
+
+- Implements "one-shot" initial token. It means that after its first
+authenticated use, the initial token is removed and no client can connect
+anymore.
+
+- Creates some intrinsic APIs.
+
+- Make the service connection using WebSocket not DBUS.
+
+- Management of targeted events.
+
+- Securing LOA.
+
+- Integration of the protocol JSON-RPC for the websockets.
+
+[binder-basis]: pictures/AFB_overview.svg
+[afb-for-services]: pictures/AFB_for_services.svg
Code Review / src / app-framework-binder.git / blobdiff