Promql Cody

PromQL-Cody

In memoriam. This skill is named after and dedicated to the late Cody Smith

PromQL-Cody is the unified Agent Skill for o11y-analysis-tools: it teaches an agent how to use all six PromQL/Alertmanager CLIs in this repo together — which are safe to run unattended, which need a human in the loop, and what order they belong in. Load the per-tool skill (skills/<tool>/SKILL.md) for the exact flags and output format of whichever tool this points you at; this skill is the map, not the detail.

The six tools at a glance

* Only when its ephemeral Alertmanager is loaded with a skeleton config that overrides receiver connection details. Pointed at a real/unmodified Alertmanager config, it can dispatch real notifications and is not hermetic.

Two families of tools

1. Hermetic static analyzers — promql-fmt, label-check, autogen-promql-tests. These are pure functions over the rule files on disk: same input, same output, every time. They need no network access and no running Prometheus. This makes them safe to run unattended and to wire into CI as required, blocking checks on every commit or pull request.

2. Historical-data tools — alert-hysteresis, stale-alerts-analyzer. Both query a live Prometheus's ALERTS metric over --timeframe/ --timehorizon to reason about real firing behavior. Their output is only as trustworthy as Prometheus's retention window (an alert can look "stale" simply because the lookback exceeds retention). They are not reproducible in CI — there's no fixture that substitutes for months of real production firing patterns — so treat them as interactive, judgment-assisted tools you run during an alert-quality review, not as a merge-blocking gate.

e2e-alertmanager-test needs a live Alertmanager to POST alerts to, but that instance can be a short-lived container, and — unlike the two tools above — its output doesn't depend on irreproducible production history. Point that ephemeral Alertmanager at a skeleton config that preserves the team's real route:/inhibit_rules: but overrides every receiver's connection details (SMTP smarthost, Slack/webhook URLs) with local no-op values, and the whole run becomes fully hermetic: real routing logic is still exercised, but no notification ever leaves the runner. That's what makes it safe to run in CI — its payoff there is a generated notification-preview artifact that reviewers can diff release over release, the way a snapshot test diffs UI screenshots. See the e2e-alertmanager-test skill for how to build that skeleton config.

Suggested workflow

1. Author or edit alert/recording rules in *.yml.
2. promql-fmt --check (or --fix) — formatting gate.
3. label-check --labels=job,... — required-label gate.
4. autogen-promql-tests --rules=... — interactively, the first time a rule is added, to scaffold a _test.yml (then hand-fill the TODOs).
5. promtool test rules ./*_test.yml — run the generated unit tests.
6. e2e-alertmanager-test --tests=... --output=full against an ephemeral Alertmanager loaded with a skeleton config in CI — produces a diffable notification-preview artifact without sending any real notification.
7. Periodically (e.g. quarterly, or when on-call flags alert fatigue), run alert-hysteresis and stale-alerts-analyzer interactively against production Prometheus to tune for: durations and cull dead alerts.

Steps 2–3 (and 6, given a disposable Alertmanager) belong in CI. Steps 4 and 7 are deliberately interactive — they either need a human to fill in generated placeholders or a human to interpret a statistical recommendation before touching production alerting.

Agent workflow

1. When a user's request touches PromQL/Alertmanager rules in this repo, start here rather than guessing which of the six tools applies — match their intent (format? validate labels? bootstrap tests? preview a notification? investigate a noisy alert? find dead alerts?) against the table above.
2. Load the specific skills/<tool>/SKILL.md for the tool(s) that match before invoking anything — it has the exact flags, output format, and exit-code semantics this skill deliberately omits.
3. Default hermetic tools (promql-fmt, label-check, autogen-promql-tests, e2e-alertmanager-test with a skeleton config) to CI-safe, automatable usage. Default the two historical-data tools to interactive use with a human reviewing the recommendation — never wire them into a merge-blocking gate.
4. For install/setup instructions (this skill, the six tool skills, or the binaries themselves via Homebrew/go install/ghcr.io containers), see INSTALLING.md and AGENTS.md at the repo root.