Add New Relic billing plugin

manifest

@@ -3,3 +3,4 @@
 datadog
 mongodb-atlas
 openai
+newrelic

pkg/plugins/newrelic/README.md

@@ -0,0 +1,95 @@
+# New Relic OpenCost Plugin
+
+The New Relic plugin imports New Relic usage data into OpenCost Custom Costs.
+
+It uses New Relic NerdGraph:
+
+```text
+POST https://api.newrelic.com/graphql
+```
+
+New Relic documents NerdGraph access with the `API-Key` header and the `actor.account(id: ...).nrql(query: ...) { results }` GraphQL shape. New Relic billing usage docs recommend NRQL queries over `NrConsumption`, `NrMTDConsumption`, and `NrDailyUsage` for usage and billing analysis.
+
+## Configuration
+
+Create a plugin config JSON file:
+
+```json
+{
+  "new_relic_api_key": "<new-relic-user-key>",
+  "account_id": 123456,
+  "gigabytes_ingested_unit_price": 0,
+  "core_ccu_unit_price": 0,
+  "advanced_ccu_unit_price": 0,
+  "synthetic_check_unit_price": 0,
+  "log_level": "info"
+}
+```
+
+Optional fields:
+
+```json
+{
+  "nerdgraph_url": "https://api.newrelic.com/graphql",
+  "account_name": "production",
+  "currency": "USD",
+  "metric_prices": {
+    "gigabytes_ingested": 0,
+    "core_ccu": 0,
+    "advanced_ccu": 0,
+    "synthetic_checks": 0
+  }
+}
+```
+
+For EU data center accounts, set:
+
+```json
+{
+  "nerdgraph_url": "https://api.eu.newrelic.com/graphql"
+}
+```
+
+New Relic contract pricing depends on the customer's plan. Configure the unit price fields or `metric_prices` to convert usage into cost. When prices are left at zero, the plugin still reports usage quantities with zero billed cost.
+
+## Default Queries
+
+The plugin requests one NerdGraph NRQL result set per daily OpenCost window. Default queries use documented New Relic usage events and alias the measured value as `usageQuantity`:
+
+- `NrConsumption` `sum(GigabytesIngested)` where `productLine = 'DataPlatform'`, faceted by `usageMetric` and `consumingAccountId`
+- `NrConsumption` `sum(consumption)` where `metric = 'CoreCCU'`, faceted by `dimension_productCapability` and `consumingAccountId`
+- `NrConsumption` `sum(consumption)` where `metric = 'AdvancedCCU'`, faceted by `dimension_productCapability` and `consumingAccountId`
+- `NrDailyUsage` synthetic check counts, faceted by `syntheticsTypeLabel`, `syntheticsMonitorName`, and `consumingAccountId`
+
+Only daily resolution is supported.
+
+## Custom Queries
+
+You can replace the default query set with `usage_queries`:
+
+```json
+{
+  "new_relic_api_key": "<new-relic-user-key>",
+  "account_id": 123456,
+  "usage_queries": [
+    {
+      "name": "full_platform_users",
+      "nrql": "FROM NrMTDConsumption SELECT latest(FullPlatformUsersBillable) AS usageQuantity SINCE '{start}' UNTIL '{end}'",
+      "quantity_attribute": "usageQuantity",
+      "unit": "user",
+      "unit_price": 0,
+      "price_key": "full_platform_users",
+      "resource_type": "FullPlatformUsers",
+      "facet_attributes": []
+    }
+  ]
+}
+```
+
+Supported NRQL template placeholders:
+
+- `{start}` and `{end}` render as `YYYY-MM-DD HH:MM:SS UTC`
+- `{start_rfc3339}` and `{end_rfc3339}` render as RFC3339
+- `{start_unix}` and `{end_unix}` render as Unix seconds
+
+For custom queries, alias the billed quantity as `usageQuantity` or set `quantity_attribute` to match the numeric result key returned by NerdGraph.