Failed calculating breakdown cost of google_compute_region_instance_group_manager

[YuvalFireFly]

I am running Infracost on my Terraform plan output. I use API requests for the /breakdown path.
In my plan, I have an existing resource with no changes with the type google_compute_region_instance_group_manager.
When running Infracost, the results of the past breakdown of the monthly cost of the resource seem correct, while the results of the breakdown are always zero. Therefore, the monthly cost diff always shows a decrease in cost even when no resources were changed.

HCL code:

resource "google_compute_region_instance_group_manager" "instance_group_us_east4" {
  provider = google-beta
  name     = "instance-group-us-east4"

  base_instance_name               = "instance-us-east4"
  region                           = "us-east4"
  distribution_policy_zones        = ["us-east4-a", "us-east4-b", "us-east4-c"]
  distribution_policy_target_shape = "EVEN"

  version {
    instance_template = data.google_compute_instance_template.instance_template.self_link
  }

  auto_healing_policies {
    health_check      = google_compute_health_check.instance_health_check.self_link
    initial_delay_sec = 120
  }

  update_policy {
    instance_redistribution_type   = "PROACTIVE"
    max_surge_fixed                = 3
    max_unavailable_fixed          = 3
    minimal_action                 = "REPLACE"
    replacement_method             = "SUBSTITUTE"
    type                           = "OPPORTUNISTIC"
    most_disruptive_allowed_action = "REPLACE"
  }

  instance_lifecycle_policy {
    force_update_on_repair = "YES"
  }

  lifecycle {
    ignore_changes = [version]
  }
}

Plan output values:

{
  "address": "google_compute_region_instance_group_manager.instance_group_us_east4",
  "mode": "managed",
  "type": "google_compute_region_instance_group_manager",
  "name": "instance_group_us_east4",
  "provider_name": "registry.terraform.io/hashicorp/google-beta",
  "change": {
    "actions": [
      "no-op"
    ],
    "before": {
      "all_instances_config": [
        
      ],
      "auto_healing_policies": [
        {
          "health_check": "https://www.googleapis.com/compute/beta/projects/firefly/global/healthChecks/firefly-instance",
          "initial_delay_sec": 120
        }
      ],
      "base_instance_name": "instance-us-east4",
      "description": "",
      "distribution_policy_target_shape": "EVEN",
      "distribution_policy_zones": [
        "us-east4-a",
        "us-east4-b",
        "us-east4-c"
      ],
      "fingerprint": "WlZjqiGxh_k=",
      "id": "projects/firefly/regions/us-east4/instanceGroupManagers/instance-group-us-east4",
      "instance_group": "https://www.googleapis.com/compute/v1/projects/firefly/regions/us-east4/instanceGroups/instance-group-us-east4",
      "instance_lifecycle_policy": [
        {
          "force_update_on_repair": "YES"
        }
      ],
      "list_managed_instances_results": "PAGELESS",
      "name": "firefly-instance-group-us-east4",
      "named_port": [
        
      ],
      "project": "firefly",
      "region": "us-east4",
      "self_link": "https://www.googleapis.com/compute/v1/projects/firefly/regions/us-east4/instanceGroupManagers/instance-group-us-east4",
      "stateful_disk": [
        
      ],
      "stateful_external_ip": [
        
      ],
      "stateful_internal_ip": [
        
      ],
      "status": [
        {
          "all_instances_config": [
            {
              "effective": true
            }
          ],
          "is_stable": false,
          "stateful": [
            {
              "has_stateful_config": false,
              "per_instance_configs": [
                {
                  "all_effective": true
                }
              ]
            }
          ],
          "version_target": [
            {
              "is_reached": true
            }
          ]
        }
      ],
      "target_pools": [
        
      ],
      "target_size": 120,
      "timeouts": null,
      "update_policy": [
        {
          "instance_redistribution_type": "PROACTIVE",
          "max_surge_fixed": 3,
          "max_surge_percent": 0,
          "max_unavailable_fixed": 3,
          "max_unavailable_percent": 0,
          "min_ready_sec": 0,
          "minimal_action": "REPLACE",
          "most_disruptive_allowed_action": "REPLACE",
          "replacement_method": "SUBSTITUTE",
          "type": "OPPORTUNISTIC"
        }
      ],
      "version": [
        {
          "instance_template": "https://www.googleapis.com/compute/v1/projects/firefly/global/instanceTemplates/instance-template-us-east4",
          "name": "",
          "target_size": [
            
          ]
        }
      ],
      "wait_for_instances": false,
      "wait_for_instances_status": "STABLE"
    },
    "after": {
      "all_instances_config": [
        
      ],
      "auto_healing_policies": [
        {
          "health_check": "https://www.googleapis.com/compute/beta/projects/firefly/global/healthChecks/firefly-instance",
          "initial_delay_sec": 120
        }
      ],
      "base_instance_name": "instance-us-east4",
      "description": "",
      "distribution_policy_target_shape": "EVEN",
      "distribution_policy_zones": [
        "us-east4-a",
        "us-east4-b",
        "us-east4-c"
      ],
      "fingerprint": "WlZjqiGxh_k=",
      "id": "projects/firefly/regions/us-east4/instanceGroupManagers/instance-group-us-east4",
      "instance_group": "https://www.googleapis.com/compute/v1/projects/firefly/regions/us-east4/instanceGroups/instance-group-us-east4",
      "instance_lifecycle_policy": [
        {
          "force_update_on_repair": "YES"
        }
      ],
      "list_managed_instances_results": "PAGELESS",
      "name": "firefly-instance-group-us-east4",
      "named_port": [
        
      ],
      "project": "firefly",
      "region": "us-east4",
      "self_link": "https://www.googleapis.com/compute/v1/projects/firefly/regions/us-east4/instanceGroupManagers/instance-group-us-east4",
      "stateful_disk": [
        
      ],
      "stateful_external_ip": [
        
      ],
      "stateful_internal_ip": [
        
      ],
      "status": [
        {
          "all_instances_config": [
            {
              "effective": true
            }
          ],
          "is_stable": false,
          "stateful": [
            {
              "has_stateful_config": false,
              "per_instance_configs": [
                {
                  "all_effective": true
                }
              ]
            }
          ],
          "version_target": [
            {
              "is_reached": true
            }
          ]
        }
      ],
      "target_pools": [
        
      ],
      "target_size": 120,
      "timeouts": null,
      "update_policy": [
        {
          "instance_redistribution_type": "PROACTIVE",
          "max_surge_fixed": 3,
          "max_surge_percent": 0,
          "max_unavailable_fixed": 3,
          "max_unavailable_percent": 0,
          "min_ready_sec": 0,
          "minimal_action": "REPLACE",
          "most_disruptive_allowed_action": "REPLACE",
          "replacement_method": "SUBSTITUTE",
          "type": "OPPORTUNISTIC"
        }
      ],
      "version": [
        {
          "instance_template": "https://www.googleapis.com/compute/v1/projects/firefly/global/instanceTemplates/instance-template-us-east4",
          "name": "",
          "target_size": [
            
          ]
        }
      ],
      "wait_for_instances": false,
      "wait_for_instances_status": "STABLE"
    },
    "after_unknown": {
      
    },
    "before_sensitive": {
      "all_instances_config": [
        
      ],
      "auto_healing_policies": [
        {
          
        }
      ],
      "distribution_policy_zones": [
        false,
        false,
        false
      ],
      "instance_lifecycle_policy": [
        {
          
        }
      ],
      "named_port": [
        
      ],
      "stateful_disk": [
        
      ],
      "stateful_external_ip": [
        
      ],
      "stateful_internal_ip": [
        
      ],
      "status": [
        {
          "all_instances_config": [
            {
              
            }
          ],
          "stateful": [
            {
              "per_instance_configs": [
                {
                  
                }
              ]
            }
          ],
          "version_target": [
            {
              
            }
          ]
        }
      ],
      "target_pools": [
        
      ],
      "update_policy": [
        {
          
        }
      ],
      "version": [
        {
          "target_size": [
            
          ]
        }
      ]
    },
    "after_sensitive": {
      "all_instances_config": [
        
      ],
      "auto_healing_policies": [
        {
          
        }
      ],
      "distribution_policy_zones": [
        false,
        false,
        false
      ],
      "instance_lifecycle_policy": [
        {
          
        }
      ],
      "named_port": [
        
      ],
      "stateful_disk": [
        
      ],
      "stateful_external_ip": [
        
      ],
      "stateful_internal_ip": [
        
      ],
      "status": [
        {
          "all_instances_config": [
            {
              
            }
          ],
          "stateful": [
            {
              "per_instance_configs": [
                {
                  
                }
              ]
            }
          ],
          "version_target": [
            {
              
            }
          ]
        }
      ],
      "target_pools": [
        
      ],
      "update_policy": [
        {
          
        }
      ],
      "version": [
        {
          "target_size": [
            
          ]
        }
      ]
    }
  }
}

Breakdown response:

{
    "name": "google_compute_region_instance_group_manager.instance_group_us_east4",
    "resourceType": "google_compute_region_instance_group_manager",
    "metadata": {},
    "hourlyCost": "0",
    "monthlyCost": "0",
    "costComponents": [
        {
            "name": "Instance usage (Linux/UNIX, on-demand, )",
            "unit": "hours",
            "hourlyQuantity": "120",
            "monthlyQuantity": "87600",
            "price": "0",
            "hourlyCost": "0",
            "monthlyCost": "0",
            "priceNotFound": true
        }
    ]
}

[aliscott]

@YuvalFireFly one thing I'm noticing is the instance type is missing? I wonder if this is causing the issue.

[YuvalFireFly]

@YuvalFireFly one thing I'm noticing is the instance type is missing? I wonder if this is causing the issue.

@aliscott What do you mean by instance type? There is no such field in google_compute_region_instance_group_manager

[aliscott]

@YuvalFireFly, sorry I mean machine_type, which it gets from the google_compute_instance_template resource.

[YuvalFireFly]

@aliscott I guess that it gets it from the instace_template self-link

"version": [
  {
    "instance_template": "https://www.googleapis.com/compute/v1/projects/firefly/global/instanceTemplates/instance-template-us-east4",
    "name": "",
    "target_size": [
      
    ]
  }
]