Table of Contents
regline
Table of Contents
Prototype: regline(regex, filename)
Return type: boolean
Description: Returns whether the anchored regular expression
regex matches a line in file filename.
Note that regex must match an entire line of the file in order to give a
true result.
Arguments:
regex: regular expression, in the range:.*filename:string, in the range:.*
Examples:
This example shows a way to determine if IPV4 forwarding is enabled or not.
bundle agent main
{
vars:
linux::
"file" string => "/proc/sys/net/ipv4/ip_forward";
"reg_enabled" string => "^1$";
"reg_disabled" string => "^0$";
classes:
linux::
"ipv4_forwarding_enabled" -> { "SecOps" }
expression => regline( $(reg_enabled) , $(file) ),
comment => "We want to know if ip forwarding is enabled because it is a
potential security issue.";
"ipv4_forwarding_disabled" -> { "SecOps" }
expression => regline( $(reg_disabled) , $(file) );
reports:
ipv4_forwarding_enabled::
"I found that IPv4 forwarding is enabled!";
ipv4_forwarding_disabled::
"I found that IPv4 forwarding is disabled.";
}
R: I found that IPv4 forwarding is disabled.
For edit_line applications it may be useful to set a class for detecting the
presence of a string that does not exactly match one being inserted. For
example:
bundle edit_line upgrade_cfexecd
{
classes:
# Check there is not already a crontab line, not identical to
# the one proposed below...
"exec_fix"
not => regline(".*cf-execd.*","$(edit.filename)"),
scope => "bundle"; # Unless you need the class outside of the bundle you
# should always scope it to the bundle. This can
# prevent issues when the bundle is used multiple
# times, and the classes promise is expected to be
# re-evaluated. If the class is namespace scoped the
# class will be available to other bundles and persist
# until it is explicitly canceled or until the end of
# the agent run.
insert_lines:
exec_fix::
"0,5,10,15,20,25,30,35,40,45,50,55 * * * * /var/cfengine/bin/cf-execd -F";
reports:
exec_fix::
"Added a 5 minute schedule to crontabs";
}