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FinFocus

AWS Cost Explorer Plugin

Overview

Section titled “Overview”

The aws-ce plugin reads billed AWS cost from AWS Cost Explorer and serves it to FinFocus. It reports what AWS charged, including discounts, reservations, and Savings Plans, rather than a list-price estimate.

The plugin only reads data. It never creates budgets, buys commitments, or changes resources.

Features

Section titled “Features”
  • Actual cost: Totals for the account or one AWS service, for up to the last 14 months, and cost for one resource by EC2 instance id or AWS ARN, for the last 14 days.
  • Forecasts: Projected cost for aws:account and aws:service is the month-to-date amortized cost plus the Cost Explorer forecast. Cost Explorer cannot forecast one resource, so a projected request for any other type returns InvalidArgument and FinFocus falls back to the next plugin.
  • Budgets: Reads AWS Budgets and reports spend and health.
  • Recommendations: EC2 rightsizing, Savings Plans, reservation purchases, and cost anomalies that AWS already holds.
  • Spot comparison: Off by default. With it on, a projected request for an EC2 instance returns the Spot price with the on-demand rate.
  • Per-request credentials: The host can pass AWS credentials or a role to assume with each request. Without them the plugin uses the AWS default credential chain.

Cost Explorer data lags usage by 24 hours or more, and resource-level data by up to 48 hours.

Installation

Section titled “Installation”
Terminal window
finfocus plugin install aws-ce

finfocus setup does not install this plugin by default.

Configuration

Section titled “Configuration”

The plugin needs AWS credentials. Set a profile or the standard AWS environment variables, and set AWS_REGION. Cost Explorer uses a global endpoint, so the region does not choose a billing dataset.

Grant only the IAM actions for the features you use:

Feature IAM actions
Account and service cost ce:GetCostAndUsage, ce:GetDimensionValues
Resource cost ce:GetCostAndUsageWithResources, ce:GetDimensionValues
Forecasts ce:GetCostForecast, ce:GetCostAndUsage
Budgets budgets:ViewBudget
Anomalies ce:GetAnomalies
Rightsizing ce:GetRightsizingRecommendation
Savings Plans recommendations ce:GetSavingsPlansPurchaseRecommendation
Reservation recommendations ce:GetReservationPurchaseRecommendation
Spot comparison ec2:DescribeSpotPriceHistory, pricing:GetProducts
Host-supplied role sts:AssumeRole
Variable Purpose Default
FINFOCUS_AWS_CE_MAX_REQUESTS_PER_MINUTE Cost Explorer and Budgets request budget per minute Unlimited
FINFOCUS_AWS_CE_MAX_WAIT_SECONDS Longest a request waits for the budget or a throttle 90
FINFOCUS_AWS_CE_MAX_BATCH_SIZE Largest batch request, 1 to 1000 100
FINFOCUS_AWS_CE_BATCH_WORKERS Concurrent batch workers, 1 to 50 50
FINFOCUS_AWS_CE_SPOT_COMPARISON true answers EC2 instance projections with a Spot quote false
FINFOCUS_AWS_ACCOUNT_ID Account for Budgets; empty uses STS GetCallerIdentity Empty

AWS charges $0.01 for each paginated Cost Explorer API request, and one FinFocus command can make several: a query with no cache hit needs at least two commitment-discovery requests and one cost request, and a long result adds a request per page. Commands that show recommendations, including cost projected, ask aws-ce for them, so they make billed requests too. FINFOCUS_AWS_CE_MAX_REQUESTS_PER_MINUTE counts every page the plugin requests, so it bounds spend. You can also leave Recommendations out of the aws-ce routing features below.

See the plugin README for the full settings list and per-request credential keys.

Routing with aws-public

Section titled “Routing with aws-public”

Without routing, FinFocus asks plugins in name order, so aws-ce is asked before aws-public. A projected request for a single resource then fails in aws-ce and falls back to aws-public. With the Spot comparison on, a Spot price can replace the on-demand list price in a stack total. Route projected cost to aws-public to avoid both:

routing:
  plugins:
    - name: aws-public
      features: [ProjectedCosts]
      priority: 20
    - name: aws-ce
      features: [ActualCosts, Recommendations, Budgets]
      priority: 10

See Routing for the full configuration.

Limits

Section titled “Limits”
  • Resource-level cost needs the Cost Explorer resource opt-in, at daily granularity, and looks back 14 days. EC2 is the only resource type checked against a live account.
  • Missing billing data returns an error, not a zero cost.
  • Rightsizing must be enabled in Cost Management preferences, and Savings Plans recommendations must already exist in AWS.
  • The caller supplies billing_account_id to get a FOCUS record.
  • finfocus plugin inspect aws-ce reports that capability discovery is not implemented, because the plugin does not implement DryRun.