Rewrite as a stand-alone snmpd agent.

* NEWS: Document new features.
* configure.ac: Raise version number.
* src/.gitignore: Update.
* src/Makefile.am: Build as an agent.
* src/main.c: New file.
* src/modconf.c: Remove "varnish" prefix from the configuration
directives.
(varnish_mib_config_init): Use program name as the base for the
configuration file name.
(varnish_mib_config_help): New function.
* src/modconf.h (progname, pid_file, pid_file_immutable): New externs.
* src/varnish-mib.8: Rewrite.
* src/varnish_mib.mib2c (varnish_snmp_init)
(varnish_snmp_deinit): Remove.
(post_config): Extern. Called from main().

1 files changed, 97 insertions, 56 deletions

diff --git a/src/varnish-mib.8 b/src/varnish-mib.8
index 6458321..0856c69 100644
--- a/src/varnish-mib.8
+++ b/src/varnish-mib.8
@@ -1,5 +1,5 @@
 .\" This file is part of Varnish-mib -*- nroff -*-
-.\" Copyright (C) 2014-2018 Sergey Poznyakoff
+.\" Copyright (C) 2014-2019 Sergey Poznyakoff
 .\"
 .\" Varnish-mib is free software; you can redistribute it and/or modify
 .\" it under the terms of the GNU General Public License as published by
@@ -13,22 +13,29 @@
 .\"
 .\" You should have received a copy of the GNU General Public License
 .\" along with Varnish-mib.  If not, see <http://www.gnu.org/licenses/>.
-.TH VARNISH-MIB 8 "February 5, 2018" "varnish-mib"
+.TH VARNISH-MIB 8 "February 14, 2019" "varnish-mib"
 .SH NAME
-varnish\-mib \- Net-SNMP module for Varnish Cache monitoring
+varnish\-mib \- Net-SNMP agent for Varnish Cache monitoring
 .SH SYNOPSIS
-In \fBsnmpd.conf\fR(5):
-.PP
-.B dlmod varnish_mib /usr/lib/snmp/varnish\-mib.so
+\fBvarnish-mib\fR\
+ [\fB\-ACHdfh\fR]\
+ [\fB\-D \ITOKEN\fR[,\fITOKEN\fR...]]\
+ [\fB\-L[eo]\fR]\
+ [\fB\-Lf \fIFILE\fR]\
+ [\fB\-Ls \fIFACILITY\fR]\
+ [\fB\-LE \fIPRI\fR[\fB\-\fIPRI2\fR]]\
+ [\fB\-c \fIFILE\fR]\
+ [\fB\-n \fINAME\fR]\
+ [\fB\-p \fIFILE\fR]
 .SH DESCRIPTION
-Dynamically loadable object module for
-.B net-snmp
-that provides access to Varnish Cache statistics.  The module is
-loaded into
+An agent for
 .BR snmpd (8)
-as shown above (actual path can of course differ, depending on how
-the package was configured).  This version is written for Varnish
-\fB5.2.1\fR.
+that provides access to Varnish Cache statistics.  To successfully
+couple with the \fBsnmpd\fR the latter must be started with the
+.B \-x
+command line option, or with the \fBmaster agentx\fR directive in
+.BR snmpd.conf (5)
+file.
 .PP
 The values in the OID branches
 .BR client ,
@@ -47,35 +54,25 @@ are obtained using \fBvarnishd\fR administrative interface (similar
 to
 .BR varnishadm (8)).
 .PP
-To retrieve this information, the module must
+To retrieve this information, the agent must
 have enough permissions to scan the Varnish management directory and
-read files located in it.  This directory is normally named 
-\fB/var/lib/varnish/\fIHOSTNAME\fB/_.vsm_mgt\fR, where \fIHOSTNAME\fR
-stands for the server's hostname.  Unless
-.BR snmpd (8)
-is run as root, special measures should be undertaken in order to
-grant access rights.  For example, if the daemon runs as user
-\fBsnmp\fR, running the following two commands after starting
-\fBvarnishd\fR will do the trick:
-
-.EX
-  setfacl -m u:snmp:rx /var/lib/varnish/$(hostname)/_.vsm_mgt
-  setfacl -m u:snmp:r /var/lib/varnish/$(hostname)/_.vsm_mgt/*
-.EE
+read files located in it.  Normally this means that it must be started
+either as root or as the user
+.B varnishd
+is started as.
 .PP
-
-.SH CONFIGURATION OPTIONS
-Configuration statements specific to
+The configuration for
 .B varnish\-mib
-must appear in the
-.B snmpd.conf
-file, after the
-.B dlmod
-statement that loads the module.
-.PP
-The following configuration statements are available:
+is read from the file
+.B varnish\-mib.conf
+located in one of the SNMP configuration path directories.  The
+following configuration directives are understood:
+.TP
+\fBpidfile\fR \fIFILE\fR
+Upon startup, write the process ID of the \fBvarnish\-mib\fR daemon to
+\fIFILE\fR.  See also the \fB\-p\fR command line option, below.
 .TP
-\fBvarnishBanTableTimeout\fR \fINUMBER\fR
+\fBbanTableTimeout\fR \fINUMBER\fR
 To create \fBbanTable\fR (see below), \fBvarnish_mib\fR connects to
 \fBvarnish\fR administration port and issues the \fBban.list\fR
 command.  To minimize the performance impact, the information obtained
@@ -83,24 +80,42 @@ is cached for a predefined amount of time (60 seconds by default).
 This amount (in seconds) is configured by \fBvarnishBanTableTimeout\fR
 statement.
 .TP
-\fBvarnishBackendTableTimeout\fR \fINUMBER\fR
+\fBbackendTableTimeout\fR \fINUMBER\fR
 Update interval for \fBbackendTable\fR.  Default is 5 seconds.
 .TP
-\fBvarnishCLIPortTimeout\fR \fINUMBER\fR
-Sets timeout for I/O operations with Varnish administrative port.
+\fBcliPortTimeout\fR \fINUMBER\fR
+Set timeout for I/O operations with Varnish administrative port.
 Default is 5 seconds.
 .PP
 The following two statements are not normally needed, but are
 provided for completeness sake:
 .TP
-\fBvarnishCLISocket\fR \fIADDRESS\fR[:\fIPORT\fR]
-Sets the address of Varnish administrative interface
-socket.
+\fBcliSocket\fR \fIADDRESS\fR[:\fIPORT\fR]
+Set the address of Varnish administrative interface socket.
+.TP
+\fBcliSecretFile\fR \fIFILE\fR
+Set the pathname of the Varnish secret file. 
+.SH OPTIONS
+.TP
+.B \-A
+Append to the log file rather than truncating it.
 .TP
-\fBvarnishCLISecretFile\fR \fIFILE\fR
-Sets the pathname of the Varnish secret file. 
-.SH DEBUGGING
-The module defines the following debugging tokens:
+\fB\-c \fIFILE\fR
+Read \fIFILE\fR as a configuration file (or a comma-separated list of
+configuration  files).
+.TP
+.B \-C
+Do not read any configuration files except the ones specified by the
+\fB\-c\fR option.
+.TP
+\fB\-d
+Dump (in hexadecimal) the sent and received SNMP packets.
+.TP
+\fB\-D \ITOKEN\fR[,\fITOKEN\fR...]
+Turn on debugging output for the given TOKEN(s).  Special token
+\fIALL\fR produces extremely verbose output.  Other tokens available
+are:
+.RS 4
 .TP
 .B varnish_mib
 Produces general debugging information.
@@ -118,6 +133,34 @@ Enables full transcript of varnish CLI session.
 .TP
 .B varnish_mib:backend
 Outputs verbose information about loading the backend information.
+.RE
+.TP
+.B \-f
+Remain in the foreground.
+.TP
+\fB\-h\fR, \fB\-?\fR
+Print a short usage summary and exit.
+.TP
+.B \-H
+Print a list of configuration file directives understood by the agent
+and then exit.
+.TP
+\fB\-Le\fR, \fB\-Lo\fR, \fB\-Lf \fIFILE\fR, \fB\-Ls \fIFACILITY\fR, \fB\-LE \fIPRI\fR[\fB\-\fIPRI2\fR]
+Specify where logging output should be directed (standard error or
+output, to a file or via syslog).  See
+.B LOGGING OPTIONS
+in
+.BR snmpcmd (5)
+for details.
+.TP
+\fB\-n \fINAME\fR
+Set an alternative application name (which will affect the
+configuration files loaded).  By default it is the same as the name
+of the binary.
+.TP
+\fB\-p \fIFILE\fR
+Save the process ID of the daemon in \fIFILE\fR.  This option
+overrides the \fBpidfile\fR configuration directive.
 .SH OIDS
 The following OIDs are defined in the
 .B VARNISH-MIB.txt
@@ -449,19 +492,16 @@ The \fBagent\fR branch is reserved for
 implementation-specific management.  It is not used currently.
 .SH NOTES
 The following OIDs were used in Varnish 4. They are no longer
-available in Varnish 5:
+available in newer Varnish releases:
 .TP
 .B clientRequests411
-Client requests received, subject to 411 errors.  This variable is
-available only in Varnish version \fR4.0\fR.
+Client requests received, subject to 411 errors.
 .TP
 .B clientRequests413
-Client requests received, subject to 413 errors.  This variable is
-available only in Varnish version \fR4.0\fR.
+Client requests received, subject to 413 errors.
 .TP
 .B backendConnUnused
-Number of unused backend connections.  This variable is available only
-in Varnish version \fR4.0\fR.
+Number of unused backend connections.
 .PP
 The OIDs
 .B clientRequestsReceived
@@ -471,6 +511,7 @@ return the same value.
 .SH "SEE ALSO"
 .BR snmpd.conf (5),
 .BR snmpd (8),
+.BR snmpcmd (1),
 .BR varnish (7),
 .BR varnishstat (1).
 .SH AUTHORS
@@ -478,7 +519,7 @@ Sergey Poznyakoff
 .SH "BUG REPORTS"
 Report bugs to <gray@gnu.org>.
 .SH COPYRIGHT
-Copyright \(co 2014-2018 Sergey Poznyakoff
+Copyright \(co 2014-2019 Sergey Poznyakoff
 .br
 .na
 License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>