oodle-synthetic

Oodle Synthetic Monitors — HTTP / TCP Checks

This skill teaches the agent to configure synthetic monitors that actually catch failures: assertions, sane intervals, and update-without-overwrite.

Prerequisites

brew install oodle-ai/oodle/oodle
oodle configure

Confirm the synthetic-monitors endpoint works:

oodle synthetic-monitors list -o json | jq 'length'

Command Execution Order

Before running any oodle command:

1. Check whether the target URL or hostport is already in context.
2. If not, ask the user to confirm the target.
3. Test the target manually (curl -I <url>) to confirm it is reachable from the public internet.
4. Run oodle synthetic-monitors create -f monitor.json.
5. After creation, verify the first run succeeded with oodle synthetic-monitors get <id> -o json.

Quick Reference

Task	Command
List monitors	oodle synthetic-monitors list -o json
Get monitor	oodle synthetic-monitors get <id> -o json
Create monitor	oodle synthetic-monitors create -f monitor.json
Update monitor	oodle synthetic-monitors update <id> -f monitor.json
Delete monitor	oodle synthetic-monitors delete <id> --force

Common Operations

Synthetic monitor schema (HTTP)

{
  "name": "API health check",
  "type": "http",
  "target": "https://api.example.com/health",
  "interval": 60,
  "assertions": [
    {"type": "statusCode",   "value": "200"},
    {"type": "responseTime", "value": "2000"}
  ]
}

Field	Meaning
type	http or tcp
target	URL (HTTP) or host:port (TCP)
interval	Seconds between probes; minimum 30, recommended ≥ 60
assertions[].type	statusCode, responseTime, bodyContains, headerEquals
assertions[].value	String form of the expected value (e.g. "200", "2000", "ok")

Synthetic monitor schema (TCP)

{
  "name": "Postgres reachability",
  "type": "tcp",
  "target": "postgres.example.com:5432",
  "interval": 60,
  "assertions": [
    {"type": "responseTime", "value": "1000"}
  ]
}

Creating a monitor

# ✅ CORRECT — manual reachability test, then create
curl -sSfI https://api.example.com/health
oodle synthetic-monitors create -f monitor.json

# ❌ WRONG — creating against an unreachable target leaves a permanently-failing monitor
oodle synthetic-monitors create -f monitor.json

Updating a monitor

# ✅ CORRECT — get → edit → update preserves all assertions
oodle synthetic-monitors get syn_123 -o json > monitor.json
jq '.interval = 30' monitor.json > monitor.new.json
oodle synthetic-monitors update syn_123 -f monitor.new.json

# ❌ WRONG — partial payload removes assertions
oodle synthetic-monitors update syn_123 -f <(echo '{"interval":30}')

Deleting a monitor

# ✅ CORRECT
oodle synthetic-monitors get syn_123 -o json > /dev/null
oodle synthetic-monitors delete syn_123 --force

# ❌ WRONG — name-grep delete
oodle synthetic-monitors delete "$(oodle synthetic-monitors list | grep health | awk '{print $1}')" --force

Best Practices

Use interval: 60 (or higher) for non-critical endpoints

A 10-second interval on every endpoint multiplies cost and noise. Reserve short intervals for critical user-facing flows.

# ✅ CORRECT — 60s interval for a /health endpoint
"interval": 60

# ❌ WRONG — 10s on dozens of internal endpoints
"interval": 10

Always include at least one statusCode assertion

A monitor with no assertions only checks TCP reachability — it will pass even if the app returns 500 to every request.

# ✅ CORRECT
"assertions": [{"type":"statusCode","value":"200"},{"type":"responseTime","value":"2000"}]

# ❌ WRONG — monitor "succeeds" on a 500 response
"assertions": []

Add a responseTime assertion to catch slow dependencies

A 200 response that takes 30 seconds is still a failure for users.

# ✅ CORRECT
"assertions": [
  {"type":"statusCode","value":"200"},
  {"type":"responseTime","value":"2000"}
]

# ❌ WRONG — only checks status code, doesn't catch latency regressions
"assertions": [{"type":"statusCode","value":"200"}]

Always get before update to preserve assertions

Update is a full-document replace.

# ✅ CORRECT
oodle synthetic-monitors get syn_123 -o json > m.json
jq '.assertions += [{"type":"bodyContains","value":"ok"}]' m.json > m.new.json
oodle synthetic-monitors update syn_123 -f m.new.json

# ❌ WRONG — drops `assertions` and `target`
oodle synthetic-monitors update syn_123 -f <(echo '{"interval":120}')

Use a stable name per environment

Encode env in the name (API health check (prod), API health check (staging)) so the alert recipient knows which env to investigate.

# ✅ CORRECT
"name": "API health check (prod)"

# ❌ WRONG
"name": "health"

Failure Handling

Error	Cause	Fix
401 Unauthorized	Invalid or missing API key	Run oodle configure or set OODLE_API_KEY
404 Not Found	Synthetic monitor ID does not exist	Verify with oodle synthetic-monitors list -o json
connection refused	Wrong OODLE_DEPLOYMENT URL	Check OODLE_DEPLOYMENT env var
Monitor permanently red	Target unreachable from the probe egress	curl -I from the public internet; check firewall, DNS, TLS cert
Monitor flaps	interval too aggressive or responseTime assertion too tight	Raise interval to 60s; raise responseTime to p95+headroom
Assertions silently dropped	update was called with a partial payload	Re-create from the last get snapshot; always get → edit → update
429 Too Many Requests	Many probes scheduled at the same second	Stagger by editing interval per monitor; use --retries 3 for bulk operations

References

• Oodle CLI repo
• Oodle docs