rsyslog配置动态日志文件-outchannel补丁

Debian Bug report logs - #477351报出了一个bug，正是我最近头疼的问题，原文如下：
Package: rsyslog
Version: 2.0.2-1~bpo40+1
Severity: normal


Hello,

on my /etc/rsyslog.conf you can read:
$template DynFile,"/var/log/system-%HOSTNAME%.log"
$outchannel porHost,$DynFile,104857600,echo test
*.* $porHost


rsyslog wants to create "/$DynFile" file, and not create
/var/log/system-%HOSTNAME%.log file .

This is with rsyslog from etch-backports.

I'll probe the sid version

-- System Information:
Debian Release: 4.0
  APT prefers stable
  APT policy: (500, 'stable')
Architecture: amd64 (x86_64)
Shell:  /bin/sh linked to /bin/bash
Kernel: Linux 2.6.18-5-xen-amd64
Locale: LANG=es_ES.UTF-8, LC_CTYPE=es_ES.UTF-8 (charmap=UTF-8)

Versions of packages rsyslog depends on:
ii  libc6                  2.3.6.ds1-13etch4 GNU C Library: Shared libraries
ii  lsb-base               3.1-23.2etch1     Linux Standard Base 3.1 init scrip
ii  zlib1g                 1:1.2.3-13        compression library - runtime

Versions of packages rsyslog recommends:
ii  logrotate                     3.7.1-3    Log rotation utility
起初，我真的以为这是个bug，后来查了源代码发现，rsyslog根本就没有实现动态文件对outchannel的支持，难道这位老兄不知道察看一下代码吗？既然rsyslog是开源的，源代码都在手上，还有什么不能做的啊？动手修改代码才是王道！以下是自用的patch，应用这个patch后可以解决自己的问题：

diff -urN rsyslog-4.6.5.orig/runtime/conf.c rsyslog-4.6.5/runtime/conf.c--- rsyslog-4.6.5.orig/runtime/conf.c    2010-11-24 22:47:07.000000000 +0800+++ rsyslog-4.6.5/runtime/conf.c    2012-08-14 08:26:25.000000000 +0800@@ -502,6 +502,32 @@     RETiRet; } +/* Get a FileName from a outchannel+ */+rsRetVal channParseFileName(uchar* p, uchar *szBuf)+{+        DEFiRet;+        size_t i;+        char szChn[128];+        struct outchannel *pOch;++        ++p; /* skip '$' */+        i = 0;+        /* get outchannel name */+        while(*p && *p != ';' && *p != ' ' &&+              i < sizeof(szChn) / sizeof(char)) {+              szChn[i++] = *p++;+        }+        szChn[i] = '\0';+        pOch = ochFind(szChn, i);+        if (pOch != NULL &&+                pOch->pszFileTemplate != NULL) {+                strcpy(szBuf, pOch->pszFileTemplate);+        }++finalize_it:+        RETiRet;+}  /* Helper to cfline() and its helpers. Parses a template name  * from an "action" line. Must be called with the Line pointerdiff -urN rsyslog-4.6.5.orig/runtime/stream.c rsyslog-4.6.5/runtime/stream.c--- rsyslog-4.6.5.orig/runtime/stream.c    2010-11-24 22:47:07.000000000 +0800+++ rsyslog-4.6.5/runtime/stream.c    2012-08-14 08:30:25.000000000 +0800@@ -96,6 +96,8 @@ resolveFileSizeLimit(strm_t *pThis, uchar *pszCurrFName) {     uchar *pParams;+    int len;+    uchar params[512] = {0};     uchar *pCmd;     uchar *p;     off_t actualFileSize;@@ -121,15 +123,22 @@     if(*p == ' ') {         *p = '\0'; /* pretend string-end */         pParams = p+1;-    } else+        len = strlen(pParams);+        strcpy(params, pParams);+    } else {         pParams = NULL;+        len = 0;+    }+    +    //拼接动态文件的名字+    strcpy(params+len, pszCurrFName);      /* the execProg() below is probably not great, but at least is is      * fairly secure now. Once we change the way file size limits are      * handled, we should also revisit how this command is run (and      * with which parameters).   rgerhards, 2007-07-20      */-    execProg(pCmd, 1, pParams);+    execProg(pCmd, 1, params);      free(pCmd); diff -urN rsyslog-4.6.5.orig/tools/omfile.c rsyslog-4.6.5/tools/omfile.c--- rsyslog-4.6.5.orig/tools/omfile.c    2010-11-24 22:47:07.000000000 +0800+++ rsyslog-4.6.5/tools/omfile.c    2012-08-14 08:26:17.000000000 +0800@@ -661,19 +661,33 @@     pData->iSizeLimit = 0; /* default value, use outchannels to configure! */      switch(*p) {-        case '$':-        CODE_STD_STRING_REQUESTparseSelectorAct(1)-        /* rgerhards 2005-06-21: this is a special setting for output-channel-         * definitions. In the long term, this setting will probably replace-         * anything else, but for the time being we must co-exist with the-         * traditional mode lines.-         * rgerhards, 2007-07-24: output-channels will go away. We keep them-         * for compatibility reasons, but seems to have been a bad idea.-         */-        CHKiRet(cflineParseOutchannel(pData, p, *ppOMSR, 0, OMSR_NO_RQD_TPL_OPTS));-        pData->bDynamicName = 0;+        case '$': {+        uchar szFileName[128] = {0};+        channParseFileName(p, szFileName);+        if (szFileName[0] == '$') {+            CODE_STD_STRING_REQUESTparseSelectorAct(2)+            CHKiRet(cflineParseOutchannel(pData, p, *ppOMSR, 0, OMSR_NO_RQD_TPL_OPTS));+            strcpy(pData->f_fname, "");+            CHKiRet(OMSRsetEntry(*ppOMSR, 1, ustrdup(&szFileName[1]), OMSR_NO_RQD_TPL_OPTS));+            pData->bDynamicName = 1;+            pData->iCurrElt = -1;          /* no current element */+            CHKmalloc(pData->dynCache = (dynaFileCacheEntry**)+                calloc(iDynaFileCacheSize, sizeof(dynaFileCacheEntry*)));+            +        } else {+            CODE_STD_STRING_REQUESTparseSelectorAct(1)+            /* rgerhards 2005-06-21: this is a special setting for output-channel+              * definitions. In the long term, this setting will probably replace+              * anything else, but for the time being we must co-exist with the+              * traditional mode lines.+              * rgerhards, 2007-07-24: output-channels will go away. We keep them+              * for compatibility reasons, but seems to have been a bad idea.+              */+            CHKiRet(cflineParseOutchannel(pData, p, *ppOMSR, 0, OMSR_NO_RQD_TPL_OPTS));+            pData->bDynamicName = 0;+        }         break;-+    }     case '?': /* This is much like a regular file handle, but we need to obtain            * a template name. rgerhards, 2007-07-03            */

打补丁时，只需要进入rsyslog-4.6.5目录，然后将patch文件放在上一级，执行patch -p1 <../rsyslog-dynchannel.patch即可。此外，还向rsyslog maillist提交了一个正式的patch：

subject:add dynimic filename support for outchannelto:[e-mail] e82f42dc9eb78fd2132b875c8718151ab9218acf Mon Sep 17 00:00:00 2001From: zhaoya <[e-mail]>Date: Tue, 7 Aug 2012 08:07:12 -0700Subject: [PATCH] add dynimic filename support for outchannelThe URL:http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=477351present a FALSE BUG! Up to the newest version,rsyslogd's "outchannel [still]doesn't get variable from template"!--- runtime/stream.c |   13 +++++++++- tools/omfile.c   |   63 +++++++++++++++++++++++++++++++++++++++++++---------- 2 files changed, 62 insertions(+), 14 deletions(-)diff --git a/runtime/stream.c b/runtime/stream.cindex bb1a0a4..49e7ec4 100644--- a/runtime/stream.c+++ b/runtime/stream.c@@ -96,6 +96,8 @@ static rsRetVal resolveFileSizeLimit(strm_t *pThis, uchar *pszCurrFName) {     uchar *pParams;+    uchar params[512] = {0};+    int len;     uchar *pCmd;     uchar *p;     off_t actualFileSize;@@ -121,15 +123,22 @@ resolveFileSizeLimit(strm_t *pThis, uchar *pszCurrFName)     if(*p == ' ') {         *p = '\0'; /* pretend string-end */         pParams = p+1;-    } else+        len = strlen(pParams);+        strcpy(params, pParams);+    } else {         pParams = NULL;+        len = 0;+    }++    //脝麓陆脫露炉脤卢脦脛录镁碌脛脙没脳脰+    strcpy(params+len, pszCurrFName);      /* the execProg() below is probably not great, but at least is is      * fairly secure now. Once we change the way file size limits are      * handled, we should also revisit how this command is run (and      * with which parameters).   rgerhards, 2007-07-20      */-    execProg(pCmd, 1, pParams);+    execProg(pCmd, 1, params);      free(pCmd); diff --git a/tools/omfile.c b/tools/omfile.cindex 1a36343..a877555 100644--- a/tools/omfile.c+++ b/tools/omfile.c@@ -333,6 +333,32 @@ rsRetVal setDynaFileCacheSize(void __attribute__((unused)) *pVal, int iNewVal)     RETiRet; } +/* Get a FileName from a outchannel+ */+rsRetVal channParseFileName(uchar* p, uchar *szBuf)+{+        DEFiRet;+        size_t i;+        char szChn[128];+        struct outchannel *pOch;++        ++p; /* skip '$' */+        i = 0;+        /* get outchannel name */+        while(*p && *p != ';' && *p != ' ' &&+              i < sizeof(szChn) / sizeof(char)) {+              szChn[i++] = *p++;+        }+        szChn[i] = '\0';+        pOch = ochFind(szChn, i);+        if (pOch != NULL &&+                pOch->pszFileTemplate != NULL) {+                strcpy(szBuf, pOch->pszFileTemplate);+        }++finalize_it:+        RETiRet;+}  /* Helper to cfline(). Parses a output channel name up until the first  * comma and then looks for the template specifier. Tries@@ -1004,19 +1030,32 @@ CODESTARTparseSelectorAct     pData->iSizeLimit = 0; /* default value, use outchannels to configure! */      switch(*p) {-        case '$':-        CODE_STD_STRING_REQUESTparseSelectorAct(1)-        /* rgerhards 2005-06-21: this is a special setting for output-channel-         * definitions. In the long term, this setting will probably replace-         * anything else, but for the time being we must co-exist with the-         * traditional mode lines.-         * rgerhards, 2007-07-24: output-channels will go away. We keep them-         * for compatibility reasons, but seems to have been a bad idea.-         */-        CHKiRet(cflineParseOutchannel(pData, p, *ppOMSR, 0, OMSR_NO_RQD_TPL_OPTS));-        pData->bDynamicName = 0;+        case '$': {+        uchar szFileName[128] = {0};+        channParseFileName(p, szFileName);+        if (szFileName[0] == '$') {+            CODE_STD_STRING_REQUESTparseSelectorAct(2)+            CHKiRet(cflineParseOutchannel(pData, p, *ppOMSR, 0, OMSR_NO_RQD_TPL_OPTS));+            strcpy(pData->f_fname, "");+            CHKiRet(OMSRsetEntry(*ppOMSR, 1, ustrdup(&szFileName[1]), OMSR_NO_RQD_TPL_OPTS));+            pData->bDynamicName = 1;+            pData->iCurrElt = -1;          /* no current element */+            CHKmalloc(pData->dynCache = (dynaFileCacheEntry**)+                calloc(iDynaFileCacheSize, sizeof(dynaFileCacheEntry*)));+        } else {    +            CODE_STD_STRING_REQUESTparseSelectorAct(1)+            /* rgerhards 2005-06-21: this is a special setting for output-channel+             * definitions. In the long term, this setting will probably replace+             * anything else, but for the time being we must co-exist with the+             * traditional mode lines.+             * rgerhards, 2007-07-24: output-channels will go away. We keep them+             * for compatibility reasons, but seems to have been a bad idea.+             */+            CHKiRet(cflineParseOutchannel(pData, p, *ppOMSR, 0, OMSR_NO_RQD_TPL_OPTS));+            pData->bDynamicName = 0;+        }         break;-+    }     case '?': /* This is much like a regular file handle, but we need to obtain            * a template name. rgerhards, 2007-07-03            */-- 1.7.4.1

此patch的意义绝大部分是为了自用，本着GPL才提交的。如此patch，就可以在配置文件中使用下面的配置了：
$template DynFile,"/var/log/system-%HOSTNAME%.log"
$outchannel porHost,$DynFile,104857600,echo test
*.* $porHost