output format (type) of gatherer 'corosync.conf' when requesting e.g. 'totem.interface'

[angelabriel]

I have seen some inconsistency (?) in the response of
/usr/bin/trento-agent facts gather --gatherer "corosync.conf" --argument "totem.interface"

When /etc/corosync/corosync.conf contains two interfaces, the gatherer returns an array holding 2 objects like
"value":[{"mcastport":5405.0,"ringnumber":0.0,"ttl":1.0},{"mcastport":5407.0,"ringnumber":1.0,"ttl":1.0}]

If only one interface is defined, the gatherer returns an object and not an array holding only one object (my expectation)
"value":{"mcastport":5405.0,"ringnumber":0.0,"ttl":1.0}

And defining three interfaces, the gatherer returns an array holding two elements, the first element is an array holding 2 objects and the second element is an object.
"value":[[{"mcastport":5405.0,"ringnumber":0.0,"ttl":1.0},{"mcastport":5407.0,"ringnumber":1.0,"ttl":1.0}],{"mcastport":5409.0,"ringnumber":2.0,"ttl":1.0}]

My expectation was to get an array holding 3 objects

When trying to use some more complex processing for the expectations like

    expect: |
        let rings = 0;
        for entry in facts.corosync_interfaces {
            if entry.ringnumber != "" {
                rings = rings + 1;
            }
        }
        if rings == values.expected_corosync_rings_per_node {
            true
        }

How can this be done, if the resulting datatype of 'facts.corosync_interfaces' is changing regarding the content of the retrieved config file?

So is this behavior intentional? What do I missing?

The same happens for --argument "nodelist.node" and even that we today only need 2 nodes for the supported scenarios for the future (with support for SAPHana 'ScaleOut') we need to support more than 2 entries in a predictable way.

Additional info:
# /usr/bin/trento-agent facts gather --gatherer "corosync.conf" --argument "totem.interface.0.ringnumber"
and
# /usr/bin/trento-agent facts gather --gatherer "corosync.conf" --argument "totem.interface.1.ringnumber"
are working well, if the config file does contain 2 interface entries.
When containing 3 interfaces, only
# /usr/bin/trento-agent facts gather --gatherer "corosync.conf" --argument "totem.interface.1.ringnumber"
is working, but
# /usr/bin/trento-agent facts gather --gatherer "corosync.conf" --argument "totem.interface.0.ringnumber"
is returning an error

[angelabriel]

And a second (related) question:
Why are the values of the entries contain a trailing '.0'?
{"mcastport":5405.0,"ringnumber":0.0,"ttl":1.0}
But in the config file it's

interface {
                ringnumber: 0
                mcastport: 5405
                ttl: 1
        }

Intentional?
If yes, we should extend the documentation to mention this, because we need to set the 'expected' values in the checks accordingly.

Note: It's not the gatherer, who added the '.0' as a

# /usr/bin/trento-agent facts gather --gatherer "corosync.conf" --argument "totem.interface"
INFO[2022-12-12 18:48:57] Using config file: /etc/trento/agent.yaml    
INFO[2022-12-12 18:48:57] loading plugins                              
INFO[2022-12-12 18:48:57] Starting corosync.conf file facts gathering process 
INFO[2022-12-12 18:48:57] Requested corosync.conf file facts gathered  
INFO[2022-12-12 18:48:57] Gathered fact for "corosync.conf" with argument "totem.interface": 
INFO[2022-12-12 18:48:57] {
  "Name": "totem.interface",
  "CheckID": "",
  "Value": {
    "Value": [
      {
        "Value": {
          "mcastport": {
            "Value": 5405
          },
          "ringnumber": {
            "Value": 0
          },
          "ttl": {
            "Value": 1
          }
        }
      },
      {
        "Value": {
          "mcastport": {
            "Value": 5407
          },
          "ringnumber": {
            "Value": 1
          },
          "ttl": {
            "Value": 1
          }
        }
      }
    ]
  },
  "Error": null
} 

shows. It's added during the evaluation of the gatherer result inside wanda?

[fabriziosestito]

this is not intentional and I am tracking it as a bug

[fabriziosestito]

@angelabriel on second thought, this shouldn't matter since for our evaluation language 1 == 1.0

[angelabriel]

Thank you @fabriziosestito This is good to know. I probably overlooked it in the rhai documentation.

[fabriziosestito]

most probably a bug, I am tracking this and we'll get you ASAP

[arbulu89]

@angelabriel Fix here: trento-project/agent#155

[angelabriel]

yeah, just saw it. Looks pretty good. Many thanks

[angelabriel]

tested the fixed gatherer with new trento-agent package trento-agent-1.2.0+git.dev24.1671109436.b619a69-150300.1.1.x86_64.rpm
Works like a charm. Many thanks for the fast fix.