[datadog_powerpacks] Implement support for basic widgets

[dashashifrina]

This pull request implements the first part of the support for the powerpack resource in Terraform.

Unfortunately, we can't immediately add all widgets since we do not validate powerpacks widgets in the public API spec. As a result, we have to manually do some validation for each new widget type. I initially tried to add all widgets, but the PR got unreasonably large, so I opted to split it out into several parts. This first part is the simplest widgets, which don't have any nested configurations. Widgets with nested configurations require extra validation which I will add on in the following PRs.

Most of the changes in this PR are cassettes and I opted to create a separate test file for each new widget.

Changes

• Add powerpack resource and support for:
  • alert_graph
  • check_status
  • free_text
  • iframe
  • image
  • note
  • servicemap
• Add test and recorded cassettes for all the widgets listed above.
• Add doc.

How to test:

1. Build the provider locally.
2. Try this powerpack resource with all the supported widgets:

resource "datadog_powerpack" "foo2" {
    name = "Sample Powerpack"
    tags = ["tag:foo1", "tag:foo2"]
    description = "Test Powerpack 2"

  template_variables {
    defaults = ["defaults"]
    name     = "datacenter"
  }
    widget {
      note_definition {
        content          = "note widget"
        background_color = "blue"
      }
      widget_layout {
        height = 12
        width = 6
        x = 5
        y = 5
      }
    }
    widget {
      free_text_definition {
        text       = "free text content"
        color      = "#d00"
        font_size  = "36"
        text_align = "left"
      }
    }
    widget {
      image_definition {
        url    = "https://google.com"
        sizing = "fit"
        margin = "small"
      }
    }
  widget {
    iframe_definition {
      url = "http://google.com"
    }
  }

  widget {
    alert_graph_definition {
      alert_id  = "895605"
      viz_type  = "timeseries"
      title     = "Widget Title"
      title_align = "center"
      title_size = "20"
    }
  }

  widget {
    servicemap_definition {
      service     = "master-db"
      filters     = ["env:prod"]
      title       = "env: prod, datacenter:dc1, service: master-db"
      title_size  = "16"
      title_align = "left"
    }
  }
  widget {
    check_status_definition {
      check     = "aws.ecs.agent_connected"
      grouping  = "cluster"
      group_by  = ["account", "cluster"]
      tags      = ["account:demo", "cluster:awseb-ruthebdog-env-8-dn3m6u3gvk"]
      title     = "Widget Title!!"
    }
  }
  widget {
    note_definition {
      content          = "note widget"
      background_color = "blue"
    }
  }
}

[drichards-87]

Created DOCS-6533 for the Docs Team editorial review.

[woodb]

First pass on the data/tests looks great! 🙌

I had one question on potentially tweaking one of the tests for consideration

[woodb]

lgtm wrt @datadog/dashboards-backend side of things 🙌

[estherk15]

I don't know how much control you have over this page, I noticed the note about the schema being generated by tfplugindocs, but some of the descriptions for the widgets don't match the UI:

• Ln 71 Service Summary widget
• Ln 74 Pie Chart widget
• Ln 76 Top List widget
• Ln 78 I'm not sure about the Trace Service widget, is this supposed to be the Profiler Flame graph widget?

[dashashifrina]

@estherk15 I believe I can manually edit the values after they're autogenerated without any issues. @skarimo is that correct? I'll make the adjustments.

Ln 71 servicemap -> this matches the Service Map widget type, no? (src)
Ln 74 sunburst -> this matches Pie Chart, will fix. [src]
Ln 76 toplist -> this matches Top List, will fix. [src]
Ln 78 trace_service -> this matches Service Summary widget type. [src]

[skarimo]

You are correct. Looks like we can use display name in the description as well to clear things up but lets do that in a separate pr as this re-uses schemas from the dashboard resource and we would be modifying that as well with these changes. The descriptions used in the docs come from its schema, for example: https://github.com/DataDog/terraform-provider-datadog/blob/master/datadog/resource_datadog_dashboard.go#L930

[skarimo]

Thanks for making the changes! Left a few minor nits but otherwise this looks great!

[skarimo]

Could we move the retry into the for loop. I fixed this up earlier this week here for the other resources: #2166

[dashashifrina]

Done 👍

[skarimo]

Suggested change

	} else {
	} else if strings.HasSuffix(widgetType, "_definition") {