Howto use real hostnames in multiple environments according "Learning CFEngine 3" book?

[HJ Coal]

Hi,

I want to set up multiple environments according the "Learning CFEngine 3" book.
These are my files, different in environments:

root@cfe-hub:/var/cfengine/masterfiles# cat environment_none/env_promises.cf
bundle agent env_main
{
  reports:
    cfengine::
      "Environment none: $(environments.active)";
}
root@cfe-hub:/var/cfengine/masterfiles# cat environment_production/env_promises.cf
bundle agent env_main
{
  reports:
    cfengine::
      "Environment prod: $(environments.active)";
}

This works:

root@cfe-hub:/var/cfengine/masterfiles# cat env1.cf
bundle common environments
{
  classes:
      "environment_production" or => {
                       "cfe_hub",
      };
  vars:
    any::
      "active" string=>"none", policy=>"overridable";
    environment_production::
      "active" string=>"production", policy=>"overridable";
}

body common control
{
      inputs=>{
        "lib/3.7/stdlib.cf",
        "environment_$(environments.active)/env_promises.cf",
      };
      bundlesequence=>{
            "environments",
            "env_main",
      };
}
root@cfe-hub:/var/cfengine/masterfiles# cf-agent -KIf /var/cfengine/masterfiles/env1.cf
R: Environment prod: production

Now, I want to have real hostnames, this works too:

root@cfe-hub:/var/cfengine/masterfiles# cat /var/cfengine/masterfiles/env2.cf
bundle common environments
{
  classes:
      "environment_production" expression  => classify("cfe-hub");

  vars:
    any::
      "active" string=>"none", policy=>"overridable";
    environment_production::
      "active" string=>"production", policy=>"overridable";
}

body common control
{
      inputs=>{
        "lib/3.7/stdlib.cf",
        "environment_$(environments.active)/env_promises.cf",
      };
      bundlesequence=>{
            "environments",
            "env_main",
      };
}
root@cfe-hub:/var/cfengine/masterfiles# cf-agent -KIf /var/cfengine/masterfiles/env2.cf
R: Environment prod: production

But when I want to use a slist for the hosts:

root@cfe-hub:/var/cfengine/masterfiles# cat /var/cfengine/masterfiles/env3.cf
bundle common environments
{
  vars:
    any::
      "prod_hosts" slist => {
                "cfe-hub",
      };

  classes:
      "environment_production" expression  => classify("$(prod_hosts)");

  vars:
    any::
      "active" string=>"none", policy=>"overridable";
    environment_production::
      "active" string=>"production", policy=>"overridable";
}

body common control
{
      inputs=>{
        "lib/3.7/stdlib.cf",
        "environment_$(environments.active)/env_promises.cf",
      };
      bundlesequence=>{
            "environments",
            "env_main",
      };
}
root@cfe-hub:/var/cfengine/masterfiles# cf-agent -KIf /var/cfengine/masterfiles/env3.cf
R: Environment none: production

What is my mistake? What is the right way?
How can I use real hostnames (not canonified) with multiple environment?

root@cfe-hub:/var/cfengine/masterfiles# cf-agent -V
CFEngine Core 3.7.1

HJ

[Nick Anderson]

Try canonify instead of classify

Sent from my mobile device.

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[HJ Coal]

Am Mittwoch, 30. September 2015 17:17:44 UTC+2 schrieb Nick Anderson:

Try canonify instead of classify

I replaced classify with canonify, but the result is the same.


The following works:
 

  classes:
      "environment_production" or  => {
                    classify("cfe-hub"),
                    classify("cfe-2nd"),
                    classify("cfe-3rd"),
                    };

(canonifiy does not work here, because of type conflict)

root@cfe-hub:~# cf-agent -KIf /var/cfengine/masterfiles/env4.cf
R: Environment prod: production

But once I try to use a variable, it behaves strange:

 

  vars:
    any::
      "host" string => "cfe-hub";

  classes:
      "environment_production" or  => {
                    classify($(host)),
                    classify("cfe-2nd"),
                    classify("cfe-3rd"),
                    };

root@cfe-hub:~# cf-agent -KIf /var/cfengine/masterfiles/env4.cf
R: Environment none: production

[Neil Watson]

My Guess is that 'or' and iteration are not getting along. Try this
instead:

body common control
{
bundlesequence => { "main", };
}

bundle agent main
{
vars:
"myhosts" slist => { "one", "two", "three", "ettin" };

classes:
"prod_env" expression => classify( "${myhosts}" );

reports:
prod_env::
"I am in prod!";
}

neil@ettin ~/.cfagent/inputs $ cf-agent -Kf ./hjcoal.cf
R: I am in prod!

'Or' expects a list on its right side so or => { @{myhosts} } would
work, but you need to canonify that list. You could do that in vars
before hand, but my example is probably fine.

-
Neil H Watson
Sr. Partner, Architecture and Infrastructure
CFEngine reporting: https://github.com/evolvethinking/delta_reporting
CFEngine policy: https://github.com/evolvethinking/evolve_cfengine_freelib
CFEngine and vim: https://github.com/neilhwatson/vim_cf3
CFEngine support: http://evolvethinking.com

[HJ Coal]

Ok, but when I try to adapt your example to dynamically select the environment, it fails:

root@cfe-hub:/var/cfengine/masterfiles# cat /var/cfengine/masterfiles/hjcoel.cf
body common control
{
      bundlesequence => { "main", "env_main"};
      inputs=>{
        "hjcoel_env_$(main.active).cf",
      };

}

#bundle common main
bundle agent main
{
  vars:
      "myhosts" slist => { "one", "two", "three", "ettin", "cfe-hub" };

  classes:
      "prod_env" expression => classify( "${myhosts}" );

      #"prod_env" or => { "one", "two", "three", "ettin", "cfe_hub" };

  vars:
    any::
      "active" string=>"none", policy=>"overridable";

    prod_env::

      "active" string=>"production", policy=>"overridable";

  reports:
    prod_env::
      "Bundle: $(this.bundle), I am in prod! Environment $(main.active)";
}

hjcoel_env_none.cf and hjcoel_env_production.cf have the same content:

root@cfe-hub:/var/cfengine/masterfiles# cat /var/cfengine/masterfiles/hjcoel_env_none.cf
bundle agent env_main
{
  reports:
      "Bundle: $(this.bundle), Environment: $(main.active), File: $(this.promise_filename)";
}

I would expect that the file hjcoel_env_production.cf is selected, because $(main.active) is equal to "production", but:

root@cfe-hub:/var/cfengine/masterfiles# cf-agent -Kf /var/cfengine/masterfiles/hjcoel.cf
R: Bundle: main, I am in prod! Environment production
R: Bundle: env_main, Environment: production, File: /var/cfengine/masterfiles/hjcoel_env_none.cf

Only if I modify hjcoal.cf to enable the commented entries, the expected output comes:

root@cfe-hub:/var/cfengine/masterfiles# cf-agent -Kf /var/cfengine/masterfiles/hjcoel.cf
R: Bundle: main, I am in prod! Environment production
R: Bundle: env_main, Environment: production, File: /var/cfengine/masterfiles/hjcoel_env_production.cf

I find that strange.

[Neil Watson]

My guess is it is something to do with how much is evaluated to figure
out inputs and bundlesequence. It's a complex process, which is one
reason that autorun was developed. I recommend you try that instead. It
has the added bonus of not having to mess with promises.cf.

Use CFEngine's mastefiles autorun policy to make cf-agent automatically run
policies in certain directories. See
https://digitalelf.net/2014/07/a-primer-on-cfengine-3-dot-6-autorun/ and a
working example:
https://github.com/evolvethinking/evolve_cfengine_freelib/blob/master/INSTALL.md
and
https://github.com/evolvethinking/evolve_cfengine_freelib/blob/master/masterfiles/services/autorun/efl.cf

--