switch config to JSON format and new rules/modifications logic

README.md

@@ -1,53 +1,82 @@
 # pymodmilter
 A pymilter based sendmail/postfix pre-queue filter with the ability to add, remove and modify e-mail headers.
 
-The project is currently in beta status, but it is already used in a productive enterprise environment which processes about a million e-mails per month.
+This project is currently in beta status, but it is already used in a productive enterprise environment which processes about a million e-mails per month.  
+The basic idea is to define rules with conditions and do modifications make changes when all conditions are met.
 
 ## Requirements
 * pymilter <https://pythonhosted.org/pymilter/>
 * netaddr <https://github.com/drkjam/netaddr/>
 
 ## Configuration
-The pymodmilter uses an INI-style configuration file. The sections are described below.
+Pymodmilter uses a configuration file in JSON format. The options are described below. Make a copy of the example configuration file in the docs folder to start with.  
 
-### Section "global"
-Any available configuration option can be set in the global section as default instead of in a rule section.
+### global (Object)
+The following optional global configuration options are available:
+* **local_addrs (Array of Strings)**  
+  A list of hosts and network addresses which are considered local. It is used to for the condition option 'local'. This option may be overriden within a rule object.
+* **log (Bool)**  
+  Enable or disable logging. This option may be overriden by a rule or modification object.
 
-The following configuration options are mandatory in the global section:
-* **rules**  
-  Comma-separated, ordered list of active rules. For each, there must be a section of the same name in the configuration.
+### rules (Array)
+A mandatory list of rule objects which are processed in the given order.
 
-### Rule sections
+### rule (Object)
 The following configuration options are mandatory for each rule:
-* **action**  
-  Set the action of this rule. Possible values are:
-  * **add**
-  * **del**
-  * **mod**
-* **header**  
-  Name of the header in case of adding a header, regular expression to match whole header lines in case of deleting or modifying a header.
-
-The following configuration options are mandatory for an add-rule:
-* **value**  
-  Value of the header.
-
-The following configuration options are mandatory for a mod-rule:
-* **search**  
-  Regular expression to match the value of header lines. You may use subgroups or named subgroups (python syntax) to include parts of the original value in the new value.
-* **value**  
-  New value of the header.
+* **modifications (Array of Objects)**  
+  A list of modification objects which are processed in the given order.
 
 The following configuration options are optional for each rule:
-* **ignore_envfrom**  
-  Regular expression to match envelop-from addresses. The rule will be skipped if the expression matches.
-* **ignore_hosts**  
-  Comma-separated list of host and network addresses. The rule will be skipped if the sending host is included here.
-* **only_hosts**  
-  Comma-separated list of host and network addresses. The rule will be skipped if the sending host is not included here. If a is included in both **ignore_hosts** and **only_hosts**, the rule will be skipped.
-* **log**  
-  Enable or disable logging of this rule. Possible values are:
-  * **true**
-  * **false**
+* **name (String)**  
+  Name of the rule.
+* **conditions (Object)**  
+  A list of conditions which all have to be true to process the rule.
+* **local_addrs (Array of Strings)**  
+  As described above in the global object section.
+* **log (Bool)**  
+  As described above in the global object section.
+
+### modification (Object)
+The following configuration options are mandatory for each modification:
+* **type (String)**  
+  Set the modification type. Possible values are:
+  * **add_header**
+  * **del_header**
+  * **mod_header**
+
+Additional parameters are mandatory based on the modification type.
+* **add_header**  
+  * **header (String)**  
+    Name of the header.
+  * **value (String)**  
+    Value of the header.
+
+* **del_header**  
+  * **header (String)**  
+    Regular expression to match against header lines.
+
+* **mod_header**  
+  * **header (String)**  
+    Regular expression to match against header lines.
+  * **search (String)**  
+    Regular expression to match against the value of header lines. You may use subgroups or named subgroups (python syntax) to include parts of the original value in the new value.
+  * **value (String)**  
+    New value of the header.
+
+The following configuration options are optional for each modification:
+* **name (String)**  
+  Name of the modification.
+* **log (Bool)**  
+  As described above in the global object section.
+
+### conditions (Object)
+The following configuration options are optional:
+* **local (Bool)**  
+  If set to true, the rule is only executed for emails originating from addresses defined in local_addrs and vice versa.
+* **hosts (Array of Strings)**  
+  A list of hosts and network addresses for which the rule should be executed.
+* **envfrom (String)**  
+  A regular expression to match against the evenlope-from addresses for which the rule should be executed.
 
 ## Developer information
 Everyone who wants to improve or extend this project is very welcome.