Cfengine Goodies

My first cf-keychain built with ThiouxReprap (download):

The goal is to maintain/detect cfid-$(sys.fqhost) host identity card file.

• test.cf :

body common control
{
  any::
    bundlesequence  => { test };
    inputs          => {
                          "/var/cfengine/inputs/cfengine_stdlib.cf",
                       };
}

bundle agent test
{

  vars:

    "l"
      slist => readstringlist("/var/cfengine/state/allclasses.txt","#.*","\n","2000","1024k");
    "sublist"
      slist => grep("(?!(Day|Min|Hr|Day|GMT_|Lcycle|Yr|Q\d|Evening|Afternoon|Morning|Monday|Tuesday|Wednesday|Thursday|Friday|Saturday|Sunday|January|February|March|April|May|June|July|August|September|October|November|December|from_cfexecd)).*","l");
    "tags"
      string => join(", ","sublist");

  files:

    "/tmp/cfid-$(sys.fqhost)"
      create        => "true",
      edit_template => "/tmp/cfid.tmpl";

  reports:

    debug::
      "$(sublist)";

}

• /tmp/cfid.tmpl :

Title: $(sys.fqhost)
Tags: $(test.tags)

Host $(sys.fqhost)
=======================

• Action :

$ cf-agent  -f ./test.cf
$ cat /tmp/cfid-blog.nanard.org

Title: blog.nanard.org
Tags: 192_168_1_1, 1_cpu, 32_bit, PK_MD5_1d68579ecaf847e03c7282690b5b9449, am_policy_hub, blog, blog_nanard_org, agent, any, cfengine, cfengine_3, cfengine_3_4, cfengine_3_4_2, org, community_edition, compiled_on_linux_gnu, debian, debian_6, debian_6_0, have_aptitude, i686, ipv4_192, ipv4_192_168, ipv4_192_168_1, ipv4_192_168_1_1, linux, linux_2_6_32_5_686, linux_i686, linux_i686_2_6_32_5_686, linux_i686_2_6_32_5_686__1_SMP_Mon_Feb_25_01_04_36_UTC_2013, mac_00_1e_8c_bf_31_91, net_iface_eth0, nanard_org, architecture_defined, architecture_virtualisation, start_monitor, update_report, virtualisation__sys_tuning_sysctl, xen_independent_wallclock_in_file, service_catalog_sys_tuning_sysctl

Host blog.nanard.org
=======================

3.5.0

New features:
 - classes promises now take an optional scope constraint.
 - new built-in functions: every, none, some, nth, sublist, uniq, filter
    classesmatching, strftime, filestat, ifelse, maparray, format
 - cf-promises flag --parse-tree is replaced by --policy-output-format=, 
    requiring the user to specify the output format (none, cf, json)
 - cf-promises allows partial check of policy 
    (without body common control) without integrity check;
   --full-check enforces integrity check
 - agent binaries support JSON input format (.json file as generated 
    by cf-promises)
 - cf-key: new options --trust-key/-t and --print-digest/-p
 - Class "failsafe_fallback" is defined in failsafe.cf when main 
    policy contains errors and failsafe is run because of this
 - add scope attribute for body classes (Redmine #2013)
 - Better diagnostics of parsing errors
 - Error messages from parser now show the context of error
 - new cf-agent option: --self-diagnostics
 - new output format, and --legacy-output
 - warnings for cf-promises.
 - Enable zeroconf-discovery of policy hubs for automatic 
    bootstrapping if Avahi is present
 - Support for sys.cpus on more platforms than Linux & HPUX

http://blog.bomgardner.org/ gone with posterous.

As I liked this 2 articles, i can't let them vanish into the void :-)

How to read in system commands and use them to calculate new variables ?

Bash script :

#!/bin/bash
#
# hugepages_settings.sh
#
# Linux bash script to compute values for the
# recommended HugePages/HugeTLB configuration
#
# Note: This script does calculation for all shared memory
# segments available when the script is run, no matter it
# is an Oracle RDBMS shared memory segment or not.
# Check for the kernel version
KERN=`uname -r | awk -F. '{ printf("%d.%d\n",$1,$2); }'`
# Find out the HugePage size
HPG_SZ=`grep Hugepagesize /proc/meminfo | awk {'print $2'}`
# Start from 1 pages to be on the safe side and guarantee 1 free HugePage
NUM_PG=1
# Cumulative number of pages required to handle the running shared memory segments
for SEG_BYTES in `ipcs -m | awk {'print $5'} | grep "[0-9][0-9]*"`
do
   MIN_PG=`echo "$SEG_BYTES/($HPG_SZ*1024)" | bc -q`
   if [ $MIN_PG -gt 0 ]; then
      NUM_PG=`echo "$NUM_PG+$MIN_PG+1" | bc -q`
   fi
done
# Finish with results
case $KERN in
   '2.4') HUGETLB_POOL=`echo "$NUM_PG*$HPG_SZ/1024" | bc -q`;
          echo "Recommended setting: vm.hugetlb_pool = $HUGETLB_POOL" ;;
   '2.6') echo "Recommended setting: vm.nr_hugepages = $NUM_PG" ;;
    *) echo "Unrecognized kernel version $KERN. Exiting." ;;
esac
# End

"meminfo" string => execresult( "${paths.path[cat] /proc/meminfo", "noshell" );

memtotal::
"memtotal" string => "${mi_array[1]";

"myvar" string => execresult( "${paths.path[bc]} <<< '${SEG_BYTES / 2', "noshell" );

You might need useshell rather than noshell.

You can pull data from ${meminfo} using regextract.

classes:
"memtotal"
 expression => regextract(
   "(?i).*?memtotal:\s*(\d*).*",
   "${meminfo}",
   "mi_array"
   );

Answered by Neil Watson

sysctl.conf hugepages and variables calculation

be careful if you want to check a directory name with regcmp

I made a mistake with regline which check if arg1 matches a line in a FILE

Code :

Simple bash script to maintain working copy on post-commit

post-commit script :

Sort columns by clicking.

from https://cfengine.com/syntax