The value of personal configuration management

Slides of the five-minute lightning talk held at the OSS4B conference in Prato, Italy, Semptember 19-20th, 2013

Transcript

1. The value of personal configuration
   management
   

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2. View Slide

3. modules in CFEngine
   ●
   modules are programs that the agent can run and that
   will write to STDOUT according to "the module protocol"
   ●
   they can be used in commands promises, or with the
   usemodule function in classes promises.
   – Ref.: modules in commands: http://tinyurl.com/oc7h9wj
   – Ref. usemodule function: http://tinyurl.com/nhjzhag
   ●
   they can set/cancel classes, and set/unset variables
   and lists
   ●
   they can be written in any language (any shell, Perl,
   Python, awk, sed, C,...)
   

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4. module examples: essid.sh
   #!/bin/bash
   PATH="/sbin:/usr/sbin:/usr/bin:/bin"
   for ESSID in $( iwgetid --raw )
   do
   CESSID=$( echo $ESSID | tr -c "a-zA-Z0-9_"
   "_" | sed -e 's/_*$//' )
   CLASS="essid_${CESSID}"
   echo "+${CLASS}"
   done
   exit 0
   

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5. module examples: location_via_exip.pl
   [...]
   my @exip_servers = map { "api-${_}01.exip.org" } qw{sth ams nyc} ;
   my $ua = LWP::UserAgent->new ;
   [... tries to get our external ip from exip ...]
   exit 1 if not defined $ip ;
   my $name = gethostbyaddr(inet_aton($ip),AF_INET) ;
   my ($second_level_domain) = ( $name =~ m{([^\.]+\.[^\.]+)$} ) ;
   my $ip_class = qq{external_ip_$ip} ;
   my $domain_class = qq{domain_$second_level_domain} ;
   $ip_class =~ tr{.}{_} ;
   $domain_class =~ tr{.}{_} ;
   print qq{=external_ip=$ip\n} ;
   print qq{=external_fqdn=$name\n} ;
   print qq{+$ip_class\n} ;
   print qq{+$domain_class\n} ;
   

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6. module examples: location_via_exip.pl
   =external_ip=87.19.216.129
   =external_fqdn=host129-216-dynamic.19-87-r.retail
   .telecomitalia.it
   +external_ip_87_19_216_129
   +domain_telecomitalia_it
   

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7. THANK YOU!
   

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