Re: Policy/Promise to agents

Ugh, ignore the links to promises.cf and creat_a_file.cf, something is 
trying to be helpful and make links to things that shouldn't be links.

On Tuesday, August 9, 2022 at 5:57:11 PM UTC-5 Nick Anderson wrote:

> Rakesh Patel <[email protected]> writes: 
>
> First new to cf CFengine. 
>
> Hi Rakesh, Welcome! I hope you enjoy your stay. 
>
> I have a sample file called creat_a_file.cf in the /var/cfengine/master 
> directory on the hub server. 
>
> File content 
>
> Listing 1: File content
>
> #!/var/cfengine/bin/cf-agent --no-lock
> body common control{
> bundlesequence =>{"create_test_file"};}
> bundle agent create_test_file{
>     files:
>             "/tmp/test-cfengine/test-file"
>
>             edit_line => addline,
>             create => "true";}
> bundle edit_line addline{
>     insert_lines: "Cfengine is running nicely.";
>
> This policy above seems to have been truncated early (it's missing a 
> trailing }, probably just a copy pasta error since you said that you get 
> the output you expect if you run the file directly. 
>
> The file is copying to the agents but not executing. I can manually run 
> the file and get the expected output but again not automatically. What am I 
> missing. I have read that I need to modify the promise.cf file on the hub 
> server but where and what? 
>
> What you read probably mentioned promises.cf (note the s). It's in the 
> root of the policy set. promises.cf is the first policy file read by 
> cfengine components if one is not specified. 
>
> However, that's rather old advice, at least if you are running the 
> Masterfiles Policy Framework (MPF), which is the default policy set you get 
> with CFEngine. 
>
> I assume you are running the MPF (documentation here 
> <https://docs.cfengine.com/docs/master/reference-masterfiles-policy-framework.html>). 
>
>
> Now, to what you are missing … 
>
> First, your snippet is written as a *standalone* policy. It's got a body 
> common control and there can only be one of those per policy entry 
> (policy entry is the first policy file read, e.g. promises.cf or whatever 
> you give to -f or --file options to the component like cf-agent -f 
> update.cf). So, if this policy file were included into the main policy (
> promises.cf) you would get errors. So, start by stripping out body common 
> control from the file. Let's replace it with a library main bundle 
> <https://docs.cfengine.com/docs/master/reference-language-concepts-bundles.html#library-main-bundles> 
> ( bundle agent __main__, a bundle that gets called as part of the default 
> bundlesequence if none is provided). In that bundle, let's add a methods 
> type promise 
> <https://docs.cfengine.com/docs/master/reference-promise-types-methods.html> 
> to actuate your bundle agent create_test_file. 
>
> So, you end up with this: 
> Listing 2: Example Policy
>
> #!/var/cfengine/bin/cf-agent --no-lockbundle agent __main__{
>   methods:
>       
>
> "create_test_file";}bundle agent create_test_file{
>   files:
>       "/tmp/test-cfengine/test-file"
>         edit_line => addline,
>         create => "true";}
> bundle edit_line addline{
>       insert_lines: "Cfengine is running nicely.";}
>
> Now, when you run the policy file directly it should still work as 
> expected: 
>
>
> # cf-agent --no-lock --log-level info --file /home/nickanderson/org/roam/daily/work/cfengine3-yn06AG
>     info: Created directory for '/tmp/test-cfengine/test-file'
>     info: Created file '/tmp/test-cfengine/test-file', mode 0600
>     info: Inserted the promised line 'Cfengine is running nicely.' into '/tmp/test-cfengine/test-file' after locator
>     info: insert_lines promise 'Cfengine is running nicely.' repaired
>     info: Edited file '/tmp/test-cfengine/test-file'
>
> Note: Pay no attention to my filename there, it's just a temporary file 
> that I stuck your policy into when I ran it with (ob-cfengine3 
> <https://github.com/nickanderson/ob-cfengine3>) 
>
> Now, you want to include this policy file as part of your larger policy 
> set (you want it to run with promises.cf runs). 
>
> For this I recommend using Augments 
> <https://docs.cfengine.com/docs/master/reference-language-concepts-augments.html>. 
> Create /var/cfengine/masterfiles/def.json with the following content. 
>
> {
>     "inputs": [ "creat_a_file.cf" ],
>     "vars": {
>         "control_common_bundlesequence_end": [ "create_test_file" ]
>     }}
>
> The *inputs* key is relative to the policy entry or a fully qualified 
> path. You said you have creat_a_file.cf in /var/cfengine/masterfiles/. 
> *masterfiles* is the *distribution* point. The update.cf policy copies 
> things to /var/cfengine/inputs and the components 
> <https://docs.cfengine.com/docs/master/reference-components-cf-monitord.html> 
> all read from /var/cfengine/inputs by default. So here you would either 
> specify /var/cfengine/inputs/creat_a_file.cf or simply creat_a_file.cf as 
> shown. Also, the inputs key is used only by the promises.cf policy entry. 
>
> Next we defined control_common_bundlesequence_end this gets defined as 
> default:def.control_common_bundlesequence_end (the default namespace, 
> bundle def, variable control_common_bundlesequence_end). Which the MPF 
> uses as the last entry in it's body common control bundlesequence 
> <https://github.com/cfengine/masterfiles/blob/7bd864a8848180f3650940d4d353148083f8cfea/promises.cf.in#L61>. 
> This tun-able is documented here 
> <https://docs.cfengine.com/docs/master/reference-masterfiles-policy-framework.html#append-to-the-main-bundlesequence> 
> in the Masterfiles Policy Framework section of the Reference MPF Reference. 
>
> Also, I know the agents update every 5 minutes, but how can I force to 
> update it manually? 
>
> After you have made the above changes force a policy update (/var/cfengine/bin/cf-agent 
> -KIf update.cf) then try a normal policy run, perhaps with -K (aka 
> --no-lock) and -I (aka --inform, or --log-level=info). 
>
> I hope you find this helpful, good luck on your journey! 
>
> You might also enjoy the ongoing The Agent is In 
> <https://www.youtube.com/watch?v=YYS1CUggomU&list=PLh71Vl9YjMaji_jnHFZ3k4mDbyOCE3A2x> 
> series. 
>

-- 
You received this message because you are subscribed to the Google Groups "help-cfengine" group.
To unsubscribe from this group and stop receiving emails from it, send an email to [email protected].
To view this discussion on the web visit https://groups.google.com/d/msgid/help-cfengine/38c95acb-933c-4910-b99a-671cfb325d89n%40googlegroups.com.