Config mgmt Get Node Metadata Counts

[lancewf]

🔩 Description: What code changed, and why?

Adding a new endpoint that for a node's field type provides distinct values and counts.

  For each type of field requested this returns distinct values the amount of each. For example, 
  if the 'platform' field is requested 'windows' 10, 'redhat' 5, and 'ubuntu' 8 could be returned. 
  The number next to each represents the number of nodes with that type of platform.

⛓️ Related Resources

#3344

👟 How to Build and Test the Change

1. build components/config-mgmt-service && build components/automate-gateway && start_all_services
2. Add three nodes with the below commands.
   1.generate_chef_run_example | jq --arg s "failure" --arg p "windows" '.status = $s | .node.automatic.platform=$p' | send_chef_data_raw
   1.generate_chef_run_example | jq --arg s "success" --arg p "linux" '.status = $s | .node.automatic.platform=$p' | send_chef_data_raw
   1.generate_chef_run_example | jq --arg s "failure" --arg p "macos" '.status = $s | .node.automatic.platform=$p' | send_chef_data_raw
3. Call the new endpoint with curl -s -f --insecure -H "api-token: $(get_api_token)" "https://localhost/api/v0/cfgmgmt/nodes_field_value_counts?terms=platform&terms=status" | jq
4. Ensure the response looks like below.

{
  "fields": [
    {
      "terms": [
        {
          "term": "macos 8.9",
          "count": 1
        },
        {
          "term": "linux 8.9",
          "count": 1
        },
        {
          "term": "windows 8.9",
          "count": 1
        }
      ],
      "field": "platform"
    },
    {
      "terms": [
        {
          "term": "success",
          "count": 1
        },
        {
          "term": "failure",
          "count": 2
        }
      ],
      "field": "status"
    }
  ]
}

✅ Checklist

• I have read the CONTRIBUTING document.
• Tests added/updated?
• Docs added/updated?
• All commits have been signed-off for the Developer Certification of Origin.

[lancewf]

The arguments were not being used before.

[vjeffrey]

nit: "list of fields" ?
maybe include an example (of response and request) for clarity?

[vjeffrey]

maybe also add a sentence about how the counts are affected by the filters? (e.g. counts respect all filters except their own or some other wording that makes sense?)

[19][default:/src:130]# curl -s -f --insecure -H "api-token: $(get_api_token)" "https://localhost/api/v0/cfgmgmt/nodes_field_value_counts?terms=platform&terms=status" | jq
{
  "fields": [
    {
      "terms": [
        {
          "term": "mac_os_x 10.11.5",
          "count": 28
        },
        {
          "term": "linux 8.9",
          "count": 1
        },
        {
          "term": "macos 8.9",
          "count": 1
        },
        {
          "term": "windows 8.9",
          "count": 1
        }
      ],
      "field": "platform"
    },
    {
      "terms": [
        {
          "term": "missing",
          "count": 29
        },
        {
          "term": "failure",
          "count": 2
        }
      ],
      "field": "status"
    }
  ]
}
[20][default:/src:0]# curl -s -f --insecure -H "api-token: $(get_api_token)" "https://localhost/api/v0/cfgmgmt/nodes_field_value_counts?terms=platform&terms=status&filter=platform:linux*" | jq
{
  "fields": [
    {
      "terms": [
        {
          "term": "mac_os_x 10.11.5",
          "count": 28
        },
        {
          "term": "linux 8.9",
          "count": 1
        },
        {
          "term": "macos 8.9",
          "count": 1
        },
        {
          "term": "windows 8.9",
          "count": 1
        }
      ],
      "field": "platform"
    },
    {
      "terms": [
        {
          "term": "missing",
          "count": 1
        }
      ],
      "field": "status"
    }
  ]
}

[vjeffrey]

working well locally! i tried a few other api calls too:

[10][default:/src:0]# curl -s -f --insecure -H "api-token: $(get_api_token)" "https://localhost/api/v0/cfgmgmt/nodes_field_value_counts?terms=environment" | jq
{
  "fields": [
    {
      "terms": [
        {
          "term": "_default",
          "count": 28
        },
        {
          "term": "B",
          "count": 3
        }
      ],
      "field": "environment"
    }
  ]
}
[11][default:/src:0]# curl -s -f --insecure -H "api-token: $(get_api_token)" "https://localhost/api/v0/cfgmgmt/nodes_field_value_counts?terms=chef_version" | jq
{
  "fields": [
    {
      "terms": [
        {
          "term": "12.12.6",
          "count": 28
        },
        {
          "term": "12.6.0",
          "count": 3
        }
      ],
      "field": "chef_version"
    }
  ]
}

[vjeffrey]

@chef/ux-team do you have any strong opinions about this api?

i can't think of anything clearer than nodes_field_value_counts but i also kinda stared at it sideways for a min after reading the endpoint it

[susanev]

these are some random thoughts i had about this...
(but i dont have strong opinions)

• i could not look at the endpoint name and understand what it was for
• i think term might better work as value
• and field as type
• then maybe node_metadata_counts as the name

[vjeffrey]

ooooh, i like node_metadata_counts !

[lancewf]

Yeah, I have had a lot of problems naming this function. Also even talking about what it does. I will update it to the above suggestions.

[lancewf]

I renamed all the function names and parameters. I also added more comments and descriptions to the functions.