From 965c09147c8f87e4ed6ece46b9d54e612e35cf11 Mon Sep 17 00:00:00 2001 From: Rainer Gerhards Date: Sun, 24 Feb 2008 17:53:16 +0000 Subject: - added some thoughts on RainerScript - worked a bit on conversion functions --- doc/rainerscript.html | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) create mode 100644 doc/rainerscript.html (limited to 'doc/rainerscript.html') diff --git a/doc/rainerscript.html b/doc/rainerscript.html new file mode 100644 index 00000000..22415258 --- /dev/null +++ b/doc/rainerscript.html @@ -0,0 +1,37 @@ + + +RainerScript ABNF + + + +

RainerScript ABNF

This is the formal definition of RainerScript, as supported by +rsyslog configuration. Please note that this currently is working +document and the actual implementation may be quite different.

The +first glimpse of RainerScript will be available as part of rsyslog +3.12.0 expression support. However, the 3.12. series of rsyslog will +have a partial script implementaiton, which will not necessariy be +compatible with the later full implementation. So if you use it, be +prepared for some config file changes as RainerScript evolves.

C-like comments (/* some comment */) are supported in all pure +RainerScript lines. However, legacy-mapped lines do not support them. +All lines support the hash mark "#" as a comment initiator. Everything +between the hash and the end of line is a comment (just like // in C++ +and many other languages).

Formal Definition

Below is the formal language definitionin ABNF (RFC 2234) +format:
+

; all of this is a working document and may change! -- rgerhards, 2008-02-24

script    := *stmt
stmt      := (if_stmt / block / vardef / run_s / load_s)
vardef    := "var" ["scope" = ("global" / "event")] 
block     := "begin" stmt "end"
load_s    := "load" constraint ("module") modpath params ; load mod only if expr is true
run_s     := "run" constraint ("input") name
constraint:= "if" expr ; constrains some one-time commands
modpath   := expr
params    := ["params" *1param *("," param) "endparams"]
param     := paramname) "=" expr
paramname := [*(obqualifier ".") name]
modpath:= ; path to module
?line? := cfsysline / cfli
cfsysline:= BOL "$" *char EOL ; how to handle the first line? (no EOL in front!)
BOL := ; Begin of Line - implicitely set on file beginning and after each EOL
EOL := 0x0a ;LF
if_stmt := "if" expr "then"
old_filter:= BOL facility "." severity ; no whitespace allowed between BOL and facility!
facility := "*" / "auth" / "authpriv" / "cron" / "daemon" / "kern" / "lpr" / 
 "mail" / "mark" / "news" / "security" / "syslog" / "user" / "uucp" / 
 "local0" .. "local7" / "mark"
	; The keyword security should not be used anymore
	; mark is just internal
severity := TBD ; not really relevant in this context

; and now the actual expression
expr := e_and *("or" e_and)
e_and := e_cmp *("and" e_cmp)
e_cmp := val 0*1(cmp_op val)
val := term *(("+" / "-") term)
term := factor *(("*" / "/" / "%") factor)
factor := ["not"] ["-"] terminal
terminal := var / constant / function / ( "(" expr ")" )
function := name "(" *("," expr) ")"
var := "$" varname
varname := msgvar / sysvar
msgvar := name
sysvar := "$" name
name := alpha *(alnum)
constant := string / number
string := simpstr / tplstr ; tplstr will be implemented in next phase
simpstr := "'" *char "'" ; use your imagination for char ;)
tplstr := '"' template '"' ; not initially implemented
number := ["-"] 1*digit ; 0nn = octal, 0xnn = hex, nn = decimal
cmp_op := "==" / "!=" / "<>" / "<" / ">" / "<=" / ">=" / "contains" / "startswith"
digit := %x30-39
alpha := "a" ... "z" # all letters
alnum :* alpha / digit / "_"

Samples

Some samples of RainerScript:

define function IsLinux
begin
if $environ contains "linux" then return true else return false
end

load if IsLinux() 'imklog.so' params name='klog' endparams /* load klog under linux only */
run if IsLinux() input 'klog'
load 'ommysql.so'

if $message contains "error" then
action
type='ommysql.so', queue.mode='disk', queue.highwatermark = 300,
action.dbname='events', action.dbuser='uid',
[?action.template='templatename'?] or [?action.sql='insert into table... values('+$facility+','+$severity+...?]
endaction

... or ...

define action writeMySQL
type='ommysql.so', queue.mode='disk', queue.highwatermark = 300,
action.dbname='events', action.dbuser='uid',
[?action.template='templatename'?] or [?action.sql='insert into table... values('+$facility+','+$severity+...?]
endaction

if $message contains "error" then action writeMySQL

ALTERNATE APPROACH

define function IsLinux(
if $environ contains "linux" then return true else return false
)

load if IsLinux() 'imklog.so' params name='klog' endparams /* load klog under linux only */
run if IsLinux() input 'klog'
load 'ommysql.so'

if $message contains "error" then
action(
type='ommysql.so', queue.mode='disk', queue.highwatermark = 300,
action.dbname='events', action.dbuser='uid',
[?action.template='templatename'?] or [?action.sql='insert into table... values('+$facility+','+$severity+...?]
)

... or ...

define action writeMySQL(
type='ommysql.so', queue.mode='disk', queue.highwatermark = 300,
action.dbname='events', action.dbuser='uid',
[?action.template='templatename'?] or [?action.sql='insert into table... values('+$facility+','+$severity+...?]
)

if $message contains "error" then action writeMySQL(action.dbname='differentDB')

[rsyslog.conf overview] +[manual index] [rsyslog site]

+ \ No newline at end of file -- cgit