rollops-plugin-cloudwatch

A Rollops metric-provider plugin backed by AWS CloudWatch. It resolves a CloudWatch metric query to a single scalar so rollout analysis can gate a canary on CloudWatch metrics, the way it does on Prometheus.

How it works

Rollops calls the plugin's query_metric tool with a query. Because a CloudWatch metric is multi-field, the query is a small JSON object:

{
  "namespace": "AWS/ApplicationELB",
  "metricName": "HTTPCode_Target_5XX_Count",
  "stat": "Sum",
  "period": 300,
  "dimensions": { "LoadBalancer": "app/web/abc", "TargetGroup": "targetgroup/web/def" }
}

The plugin runs aws cloudwatch get-metric-statistics over a lookback window (default 5m) and returns the requested statistic of the most recent datapoint. It drives AWS through the aws CLI using ambient credentials (env, profile, or IAM role) — no AWS SDK or request signing is compiled in.

Wire those values into a CEL condition in the analysis block:

analysis:
  provider: cloudwatch
  plugin: ~/.rollops/plugins/cloudwatch
  sha256: <pin>
  metrics:
    - name: errors5xx
      query: '{"namespace":"AWS/ApplicationELB","metricName":"HTTPCode_Target_5XX_Count","stat":"Sum","dimensions":{"LoadBalancer":"app/web/abc"}}'
  condition: "errors5xx < 5"
  count: 3
  interval: 60s

Configuration

aws resolves credentials as usual; the plugin reads only its own knobs from the environment (the Rollops target spec carries only the JSON query):

Env var	Required	Default	Description
CLOUDWATCH_AWS	no	aws	aws binary to use
CLOUDWATCH_REGION	no	—	--region override
CLOUDWATCH_WINDOW	no	5m	lookback window (Go duration)

Install

rollops plugin install cloudwatch

License

MIT