now

Table of Contents

Prototype: now()

Return type: int

Description: Return the time at which this agent run started in system representation.

In order to provide an immutable environment against which to converge, this value does not change during the execution of an agent.

Examples:

Reporting the system time of agent start and calculating what yesterday was.

bundle agent example_now
{
  vars:
      "epoch" int => now();

      "24_hours_ago"
        string => format( "%d",
                          eval( "$(epoch)-86400", math, infix ));

  reports:
      "Today is $(with) or in unix format '$(epoch)'"
        with => strftime( gmtime, "%Y-%m-%d %T", $(epoch) );

      "24 hours ago was $(with) or in unix format '$(epoch)'"
        with => strftime( gmtime, "%Y-%m-%d %T", $(24_hours_ago) );
}

bundle agent __main__
{
  methods:
      "example_now";
}

Output:

R: Today is 2019-06-12 20:40:00 or in unix format '1560372000'
R: 24 hours ago was 2019-06-11 20:40:00 or in unix format '1560372000'

files type promises using file_select to limit recursive file selection based on a time relative to the agent start can make use of this function.

    bundle agent gzip_recent_pdfs
    {
       files:

         # Ensure that any file ending in .pdf that has been
         # modified in the last year is compressed

         "/tmp/"
           file_select => pdf_modified_within_last_year,
           transformer => '/bin/gzip $(this.promiser)';
    }

    body file_select pdf_modified_within_last_year
    # @brief Sllect files that have been modified in the last year AND end in .pdf
    {
      mtime       => irange(ago(1,0,0,0,0,0),now);
      leaf_name => { ".*\.pdf" };
      file_result => "mtime.leaf_name";
    }

processes type promises using process_select can use this function to select processes based on relative execution time.

bundle agent main

{
  processes:

      "init"
        process_count   => any_count("booted_over_1_day_ago"),
        process_select  => days_older_than(1),
    comment => "Define a class indicating we found an init process running
                    for more than 1 day.";

  reports:

    booted_over_1_day_ago::

      "This system was booted over 1 days ago since there is an init process
       that is older than 1 day.";

    !booted_over_1_day_ago::
      "This system has been rebooted recently as the init process has been
       running for less than a day";
}



body process_count any_count(cl)
{
      match_range => "0,0";
      out_of_range_define => { "$(cl)" };
}


body process_select days_older_than(d)
{
      stime_range    => irange(ago(0,0,"$(d)",0,0,0),now);
      process_result => "!stime";
}

This policy can be found in /var/cfengine/share/doc/examples/processes_define_class_based_on_process_runtime.cf and downloaded directly from github.

See also: