Files
cairnobs/alerting/internal/config/config.go
T
jcoffey-dev 9435115ab7 Phase 3: dashboards and alerting
Saved, shareable multi-panel dashboards (table/line/bar/single-stat
panels via gridstack + uPlot, global + per-panel time range, JSON
export/import) and threshold/absence alert rules with an
ok/pending/firing evaluator and webhook/Slack/PagerDuty delivery.

- New /metadata component: Postgres control-plane store for dashboards,
  panels, notification targets, alert rules/state, and delivery log --
  see docs/phase-3-dashboard-design.md for why ClickHouse's MergeTree
  family isn't a fit for this access pattern (needs real row-level
  locking and read-your-writes consistency).
- api/internal/dashboards: dashboard/panel CRUD, pure -- panel query
  execution stays client-side, reusing the existing /query endpoint.
- New /alerting service: rule/target CRUD, a ticker-driven evaluator
  (claim-then-evaluate concurrency control, transactional-outbox
  delivery, query errors and threshold zero-rows never coerced into a
  false transition) and webhook/Slack/PagerDuty delivery with
  retry/backoff. See docs/phase-3-alerting-design.md for the full
  state-machine design and the four correctness properties it
  implements.
- web: /dashboards and /alerts UIs; cli: sentryctl dashboards/alerts
  list/get/apply, seeding a future Terraform provider's JSON contract.
- hack/alert-load-test: 500 rules against real ClickHouse data, real
  measured results in docs/phase-3-runbook.md.

Five real bugs found by actually running this against a live stack
(documented in the runbook, not just fixed silently): a latent Phase 2
bug where ClickHouse rejected the timestamp format used for
earliest=/latest= queries; a "now" literal token injected into query
text; a GridStack/uPlot layout-timing race; JS's Date.parse being too
lenient to use as a timestamp-detection heuristic; a rule's "enabled"
field silently defaulting to false when omitted; and the evaluator's
claim-batch-size and worker-pool-concurrency defaulting to the same
value, causing 500 concurrently-due rules to take 125s to cycle through
instead of the configured 60s.
2026-08-13 17:29:38 -07:00

97 lines
3.4 KiB
Go

// Package config loads alerting's configuration from environment
// variables, same convention as /api and /ingest: no config file format.
package config
import (
"fmt"
"os"
"strconv"
"time"
)
type Config struct {
HTTPListenAddr string
Postgres PostgresConfig
APIQueryURL string // base URL of /api, e.g. http://api:8080 -- alerting never talks to ClickHouse/Tantivy directly
CORSAllowedOrigin string
Evaluator EvaluatorConfig
}
type PostgresConfig struct {
Addr string
Database string
Username string
Password string
}
type EvaluatorConfig struct {
TickInterval time.Duration // how often the scheduler checks for due rules
// ClaimBatchSize and WorkerPoolSize are deliberately separate knobs,
// not the same number: ClaimBatchSize bounds how many due rules one
// tick pulls off the queue (needs to be large enough to drain a
// backlog when many rules share a due time, e.g. right after bulk
// creation), while WorkerPoolSize bounds concurrent /query calls
// within that batch. Found by actually running hack/alert-load-test
// with 500 rules and both numbers defaulted to the same value
// (20): the evaluator took 125s to cycle through 500 due rules
// instead of the configured 60s eval_interval_seconds, because each
// 5s tick could only claim 20 rules regardless of how many more were
// already due -- see /docs/phase-3-runbook.md's load-test section.
ClaimBatchSize int
WorkerPoolSize int
QueryTimeout time.Duration // per-evaluation POST /query timeout
}
func Load() (Config, error) {
cfg := Config{
HTTPListenAddr: getenv("HTTP_LISTEN_ADDR", ":8081"),
Postgres: PostgresConfig{
Addr: getenv("POSTGRES_ADDR", "localhost:5432"),
Database: getenv("POSTGRES_DATABASE", "sentry_metadata"),
Username: getenv("POSTGRES_USERNAME", "sentry"),
Password: getenv("POSTGRES_PASSWORD", ""),
},
APIQueryURL: getenv("API_QUERY_URL", "http://localhost:8080"),
// Same "no auth yet" tradeoff as api's CORSAllowedOrigin default --
// see api/internal/config/config.go's comment, same reasoning here.
CORSAllowedOrigin: getenv("CORS_ALLOWED_ORIGIN", "*"),
}
tickSec, err := strconv.Atoi(getenv("EVALUATOR_TICK_SECONDS", "5"))
if err != nil {
return Config{}, fmt.Errorf("EVALUATOR_TICK_SECONDS: %w", err)
}
cfg.Evaluator.TickInterval = time.Duration(tickSec) * time.Second
poolSize, err := strconv.Atoi(getenv("EVALUATOR_WORKER_POOL_SIZE", "20"))
if err != nil {
return Config{}, fmt.Errorf("EVALUATOR_WORKER_POOL_SIZE: %w", err)
}
cfg.Evaluator.WorkerPoolSize = poolSize
// Default well above WorkerPoolSize: this is "how many due rules can
// one tick pull off the queue," not a concurrency limit -- the
// worker pool below still bounds actual concurrent /query calls
// regardless of how large a batch gets claimed.
claimBatchSize, err := strconv.Atoi(getenv("EVALUATOR_CLAIM_BATCH_SIZE", "1000"))
if err != nil {
return Config{}, fmt.Errorf("EVALUATOR_CLAIM_BATCH_SIZE: %w", err)
}
cfg.Evaluator.ClaimBatchSize = claimBatchSize
queryTimeoutSec, err := strconv.Atoi(getenv("EVALUATOR_QUERY_TIMEOUT_SECONDS", "30"))
if err != nil {
return Config{}, fmt.Errorf("EVALUATOR_QUERY_TIMEOUT_SECONDS: %w", err)
}
cfg.Evaluator.QueryTimeout = time.Duration(queryTimeoutSec) * time.Second
return cfg, nil
}
func getenv(key, fallback string) string {
if v := os.Getenv(key); v != "" {
return v
}
return fallback
}