Services/Sync/Server/GlobalConfFile

Global Configuration File

All services on a Sync server share a common configuration. Here's a format proposal for a unique configuration file that can be used to group this configuration.

Syntax

The configuration file is a ini-based file. (See http://en.wikipedia.org/wiki/INI_file for more details.) Variables name can be assigned values, and grouped into sections. A line that starts with "#" is commented out.

Example:

 [section1]
 # comment
 name = value
 name2 = "other value"

 [section2]
 foo = bar

Ini readers in Python, PHP and other languages understand this syntax. Although, there are subtle differences in the way they interpret values an in particular if they convert them.

Values conversion

- If value is quoted with " chars, it's a string. This notation is useful to include "=" characters in the value. In case the value contains a " character, it must be escaped with a "\" character.

- When the value is composed of numbers and optionally suffixed by "-", it's converted to an integer.

- A value can be an environment variable : "${VAR}" is replaced by the value of VAR if found in the environment. It's left alone otherwise.

- A value can contains multiple lines. When read, lines are converted into a sequence of values. Each new line for a multiple lines value must start with a least one space or tab character.

Examples:

 [section1]
 # comment
 a_number = 1
 a_string = "other=value"
 another_string = other value
 a_list = one
          two
          three

Extending a file

An INI file can extend another file. For this, A "DEFAULT" section must contain an "extends" variable that can point to another INI file, which will be merged to the current file, by adding new sections and values. If the file pointed in "extends" contains section/variable names that already exist in the original file, they will not override existing ones.

file_one.ini:

 [section1]
 name2 = "other value"

 [section2]
 foo = baz
 bas = bar

file_two.ini:

 [DEFAULT]
 extends = file_one.ini    

 [section2]
 foo = bar

Result:

 [section1]
 name2 = "other value"

 [section2]
 foo = bar
 bas = bar

Sync INI files syntax

TBD