Splitting light from dark and data from policies

[Martin Simons]

Dear CFEngineer,

Some of you who know me, know I'm fond of arrays.

To be honest, I am puzzled. I thought this would work, where do I go wrong?

bundle agent common {

vars:

  "index"                        slist => getindices($(data.array));

methods:

  ""                         usebundle => usevar( $(data.test) );

  ""                         usebundle => use_array( $(data.array) );

reports:

  "$(this.bundle): $(data.test)";

  "$(this.bundle): $(index)";

}

bundle agent usevar(var) {

reports:

  "$(this.bundle): $(var)";

}

bundle agent use_array(array) {

vars:

  "index"                        slist => getindices( $(array) );

reports:

  "$(this.bundle): $(index)";

  "$(this.bundle): $(array[$(index)])";

}

bundle agent data {

vars:

  "test"                        string => "Test variable for common";

  "array[one]"                  string => "one";

  "array[two]"                  string => "two";

}

body common control

{

      bundlesequence => { common, };

      inputs => { "/root/promises.cf", };

}

Output:

root@testbox(semi production in fact):~# cf-agent -KI -f ./promises.cf 

R: usevar: Test variable for common

R: use_array: $(index)

R: use_array: $(array[$(index)])

R: common: Test variable for common

R: common: $(index)

Hope to see you in LA, December 11th.

Kind regards,

Martin.

[Nick Anderson]

Martin Simons <mjcm....@gmail.com> writes:

> Dear CFEngineer,
>
> Some of you who know me, know I'm fond of arrays.
>
> To be honest, I am puzzled. I thought this would work, where do I go wrong?

I made a few of minor modifications to your policy:

• Introduced bundle agent main instead of body common control (non functional change)
  
• Use name of variable with getindices not its expansion
  
• Pass name of array instead of its expansion.
  

bundle agent main
{
  methods:
    "common";
}
bundle agent common {
  vars:

    # Get the index from the named variable, not its expansion.
      "index"                        slist => getindices("data.array");

  

methods:
      ""                         usebundle => usevar( $(data.test) )

;

    # Pass the NAME of the variable, not its expansion.
      ""                         usebundle => use_array( "data.array" );

  reports:
      "$(this.bundle): data.test = $(data.test)";
      "$(this.bundle): index value = $(index)";

}

bundle agent usevar(var) {
  reports:
      "$(this.bundle): $(var)";
}

bundle agent use_array(array) {
  vars:
      "index"                        slist => getindices( $(array) );
  reports:
      "$(this.bundle): $(index)";
      "$(this.bundle): $(array[$(index)])";
}

bundle agent data {
  vars:
      "test"                        string => "Test variable for common";
      "array[one]"                  string => "one";
      "array[two]"                  string => "two";
}

R: usevar: Test variable for common
R: use_array: two
R: use_array: one
R: common: data.test = Test variable for common
R: common: index value = two
R: common: index value = one

–
Nick Anderson
Doer of things, CFEngine

[Martin Simons]

Dear Nick,

Thank you, you put me on the right track.

Working with arrays often is an in depth operation. This is how I meant it to be:

Code:

bundle agent common {

vars:

  "index"                        slist => getindices("data.array");

methods:

  ""                         usebundle => usevar( $(data.test) );

  ""                         usebundle => use_array( "data.array" );

reports:

  "$(this.bundle): $(data.test)";

  "$(this.bundle): $(index)";

}

bundle agent usevar(var) {

reports:

  "$(this.bundle): $(var)";

}

bundle agent use_array(array) {

vars:

  "index"                        slist => getindices( $(array) );

methods:

  ""                         usebundle => array_row("$(index)", "$($(array)[$(index)])");

reports:

  "$(this.bundle): index $(index)";

}

bundle agent array_row(index, array_row) {

vars:

reports:

  "$(this.bundle): array row $(index) $(array_row)";

}

bundle agent data {

vars:

  "test"                        string => "Test variable for common";

  "array[one]"                  string => "first element";

  "array[two]"                  string => "second element";

}

body common control

{

      bundlesequence => { common, };

      inputs => { "/root/promises.cf", };

}

Output:

R: usevar: Test variable for common

R: array_row: array row one first element

R: array_row: array row two second element

R: use_array: index one

R: use_array: index two

R: common: Test variable for common

R: common: one

R: common: two

Kind regards,

Martin.

Op donderdag 5 oktober 2017 20:15:55 UTC+1 schreef Nick Anderson: