CI Pipeline Monitor

Overview

This skill automates monitoring CI test pipelines on Azure DevOps (dnceng-public/public), triaging failures, and coordinating with GitHub dotnet/runtime issue tracking.

Pipelines to Monitor

The list of pipelines and their cached definition IDs is maintained in pipelines.md in this skill directory.

Architecture

Deterministic steps are scripted. Agent does triage.

• Python scripts (scripts/) handle all deterministic work: DB setup, build fetching, test failure extraction (including errorMessage and stackTrace from the ADO API), Helix log downloading, and report generation.
• Agent handles all non-deterministic work: reading console log files for failures where the API returned no useful error (crashes, timeouts), enriching/completing error messages and stack traces, classifying failures, grouping by root cause, searching GitHub for matching issues, writing analysis, and populating the triage tables in monitor.db.

Scripts

Use these scripts — do NOT write ad-hoc replacements. Do NOT create new files in scripts/ — only the committed scripts below belong there. For ad-hoc queries during triage (e.g., DB lookups, grouping), prefer python -c '...' inline. If a query is too complex for inline (escaping issues, multi-line), write a temp file under temp/ (e.g., temp/_query.py). The temp/ directory is gitignored; the user will clean it up when no longer needed.

End-to-end pipeline:

cd .github/skills/ci-pipeline-monitor

# Step 0: Prerequisites (agent)
pip install requests
# Obtain ADO_TOKEN — see Step 0 section below for full logic

# Step 1: Resolve pipeline definitions (agent)
# Agent compares Pipeline Details against Cached Mapping in pipelines.md,
# resolves missing def IDs via AzDO Definitions API, updates pipelines.md

# Step 2: Fetch latest builds (deterministic)
python scripts/setup_and_fetch_builds.py --pipelines pipelines.md --db scripts/monitor.db

# Step 3: Extract failed tests + fetch logs (deterministic)
python scripts/extract_failed_tests.py --db scripts/monitor.db
python scripts/fetch_helix_logs.py --db scripts/monitor.db

# Step 4: Triage (agent — non-deterministic)
# Agent reads test_results table, classifies (exit code + error message),
# groups by root cause, searches GitHub, populates failures table,
# UPDATEs test_results.failure_id for every row

# Step 5: Validate DB before report (deterministic)
python scripts/validate_results.py --db scripts/monitor.db --pipelines pipelines.md --log logs/ci-pipeline-monitor-*.log
# Step 5a: If validation fails, fix issues in DB, re-validate (up to 3 retries,
# only while failure count decreases). Log remaining WARNs and proceed.

# Step 6: Generate report (deterministic — only after DB is clean)
# Pass --validation-warnings if Step 5a had unresolved failures
python scripts/generate_report.py --db scripts/monitor.db [--validation-warnings]

Database Schema

Created by setup_and_fetch_builds.py. Populated by scripts (Steps 2-3) and agent (Step 4). Validated by validate_results.py (Step 5). Read by generate_report.py (Step 6).

CREATE TABLE pipelines (
    name            TEXT PRIMARY KEY,
    build_id        INTEGER,
    build_number    TEXT,
    result          TEXT NOT NULL,  -- succeeded | failed | inconclusive | skipped
    skip_reason     TEXT
);

-- Every individual test failure from Step 3 (before grouping).
-- One row per failed test method per pipeline. Populated by scripts.
CREATE TABLE test_results (
    id                INTEGER PRIMARY KEY AUTOINCREMENT,
    pipeline_name     TEXT NOT NULL,
    build_id          INTEGER NOT NULL,
    run_name          TEXT NOT NULL,        -- AzDO test run name (leg name)
    test_name         TEXT NOT NULL,        -- fully qualified, .WorkItemExecution stripped
    helix_job_id      TEXT,
    helix_work_item   TEXT,
    console_log_url   TEXT,
    exit_code         INTEGER,              -- from console log (script-extracted)
    console_log_path  TEXT,                 -- path to full console log file on disk (in helix-logs/)
    error_message     TEXT,                 -- initially from AzDO Test Results API; may be enriched/overwritten by agent with console-log snippet
    stack_trace       TEXT,                 -- initially from AzDO Test Results API; may be enriched/overwritten by agent with console-log snippet
    failure_id        INTEGER,              -- NULL until Step 4 assigns a group
    FOREIGN KEY (failure_id) REFERENCES failures(id)
);

CREATE TABLE failures (
    id                    INTEGER PRIMARY KEY,
    title                 TEXT NOT NULL,
    scope                 TEXT,                -- e.g. "arm64, x86"
    test_name             TEXT NOT NULL,
    work_item             TEXT,
    failure_category      TEXT,                -- timeout, crash_sigsegv, test_failure, etc.
    exit_codes            TEXT,
    failing_since_date    TEXT,
    failing_since_build   TEXT,
    console_log_url       TEXT,
    source_test_result_id INTEGER,             -- which test_results row the error_message/stack_trace came from
    error_message         TEXT,                -- verbatim from log
    stack_trace           TEXT,                -- verbatim from log
    summary               TEXT,                -- agent-written
    analysis              TEXT,                -- agent-written
    github_issue_number   INTEGER,             -- NULL if NEW
    github_issue_url      TEXT,
    github_issue_state    TEXT,                -- OPEN | CLOSED
    github_issue_assigned TEXT,
    labels                TEXT,
    milestone             TEXT DEFAULT '11.0.0'
);

CREATE TABLE failure_pipelines (
    failure_id      INTEGER NOT NULL REFERENCES failures(id),
    pipeline_name   TEXT NOT NULL,
    build_id        INTEGER,
    build_number    TEXT,
    PRIMARY KEY (failure_id, pipeline_name)
);

CREATE TABLE failure_tests (
    failure_id      INTEGER NOT NULL REFERENCES failures(id),
    pipeline_name   TEXT NOT NULL,
    run_name        TEXT NOT NULL,
    test_name       TEXT NOT NULL
);

Workflow

Debug Log

All output goes in logs/ (sibling of scripts/).

• Debug Log (logs/ci-pipeline-monitor-<timestamp>.log) — always generated. ⚠️ Write incrementally by appending after each API call and decision. Do NOT compose the log from memory at the end of the run — this defeats the crash-recovery purpose. If the process crashes mid-run, the log must contain everything up to the crash point. Use file append operations (Python open(..., 'a') or PowerShell Add-Content) to write each log entry immediately after the action it describes. Follow log-template.md. Log every API call URL + response summary, every decision with reasoning, timestamps, and errors.
• Test Report (logs/test-report-<timestamp>.md) — always generated via generate_report.py.

Step 0: Prerequisites (agent)

Run before anything else. See references/prerequisites.md for full details.

1. pip install requests
2. Ensure ADO_TOKEN env var is set (required for Step 3).

⚠️ Do NOT proceed to Step 3 without a valid ADO_TOKEN. The Test Results API returns 203 (sign-in HTML) without auth, even on dnceng-public.

Step 1: Resolve Pipeline Definitions (agent)

Compare the Pipeline Details table (source of truth) against the Cached Definition ID Mapping table in pipelines.md:

1. For each pipeline in Pipeline Details that is not marked Private or skip in its Notes column:

   • If it already has a row with a numeric Def ID in the Cached Mapping table, do nothing (already resolved).
   • If it has no row in the Cached Mapping table, or its row has — as the Def ID, resolve it via the AzDO Definitions API:

     GET https://dev.azure.com/dnceng-public/public/_apis/build/definitions?name={pipeline_name}&api-version=7.1

   • If the API returns a match, add or update the row in the Cached Mapping table with the resolved Def ID.
   • If the API returns no match, log a warning and skip that pipeline.

2. For pipelines in the Cached Mapping table that are no longer in Pipeline Details, leave them (stale rows are harmless — the script only processes pipelines present in the Cached Mapping table).

Do NOT re-resolve IDs that are already populated with a numeric value.

Step 2: Fetch Latest Builds (deterministic — scripted)

python scripts/setup_and_fetch_builds.py --pipelines pipelines.md --db scripts/monitor.db

Creates DB, fetches latest build per pipeline, populates pipelines table, outputs failing build IDs.

Step 3: Extract Failed Tests and Fetch Logs (deterministic — scripted)

python scripts/extract_failed_tests.py --db scripts/monitor.db
python scripts/fetch_helix_logs.py --db scripts/monitor.db

Extracts individual failed test methods and downloads their full Helix console logs to disk.

⚠️ Every individual failure must be INSERT'd into test_results immediately.

• extract_failed_tests.py: inserts one row per failed test method (test_name, run_name, pipeline_name, helix_job_id, helix_work_item, console_log_url, error_message, stack_trace from the ADO API). The API provides useful error/stack for most xUnit assertion failures. For crashes and timeouts, the API returns a generic "Helix Work Item failed" message — these are stored as empty so the agent can extract the real error from the console log.
• fetch_helix_logs.py: downloads the full console log to helix-logs/ (a separate directory — NOT mixed with logs/) and UPDATEs the corresponding test_results row with exit_code and console_log_path. Uses console_log_path IS NULL as the sentinel for unprocessed rows.
• After Step 3, test_results contains the complete raw inventory of every failure with its exit code, a path to the full console log on disk, and API-provided error/stack where available. failure_id is NULL — it is populated by the agent in Step 4.

Step 4: Triage Failures (agent — non-deterministic)

See references/triage-workflow.md for full instructions.

⚠️ INSERT into failures table immediately after triaging each failure group.

Step 5: Validate DB (deterministic — scripted)

python scripts/validate_results.py --db scripts/monitor.db --pipelines pipelines.md --log logs/ci-pipeline-monitor-<timestamp>.log

Runs 24 checks across data completeness, referential integrity, data quality, and content accuracy. Exits 1 on failure.

For the full list of checks, see references/validation-checks.md.

Step 5a: Fix Validation Failures (up to 3 retries)

If any checks fail after Step 5:

1. Read the validator output — each FAIL line includes the specific test_results IDs, failure IDs, or field names that failed.

2. For each fixable failure (e.g., truncated stack trace, missing error_message):

   • Look up the test_results row in the DB
   • Re-read the console log file at console_log_path
   • UPDATE the corrected field in the DB

3. Re-run the validator:

   python scripts/validate_results.py --db scripts/monitor.db --pipelines pipelines.md --log <log_path>

4. If failures decreased, repeat from step 1 (up to 3 total retries). If failures did NOT decrease (same or more), stop retrying.

5. If checks still fail after retries, log each as a WARN in the debug log with clickable links and move on:

   [WARN] Validation error persists after retry — <check description>
     Pipeline: [<name> <build_number>](<ado_test_results_tab_url>)
     Console Log: [Console Log](<helix_url>)
     Field: <field_name>, failure_id=<N>

Stop retrying when failure count stops decreasing or after 3 attempts. Log remaining WARNs and proceed to report generation. Some failures (e.g., LLM output truncation) may not be fixable programmatically.

Step 6: Generate Report (deterministic — scripted)

# If validation passed (Step 5/5a exit code 0):
python scripts/generate_report.py --db scripts/monitor.db

# If validation had unresolved warnings (Step 5/5a exit code 1):
python scripts/generate_report.py --db scripts/monitor.db --validation-warnings

Reads DB, outputs report following report-template.md. Only run after DB validation (Step 5/5a) is complete so the report is generated once.

Step 7: Bisect Regressions (agent — on request)

1. Check failing_since_date/failing_since_build from failures table
2. Get commit range between failing and last passing build
3. List PRs merged in that range via GitHub MCP server
4. Check file overlap with test's source area
5. Rank and present top candidates with evidence

Banned Tools and APIs

• ado-pipelines_* and ado-testplan_* MCP tools are banned:
  • ado-testplan_show_test_results_from_build_id returns 1M+ rows and times out.
• ado-pipelines_get_builds, get_build_log, get_build_status, get_build_changes, get_build_log_by_id
• Build Timeline API is banned (/_apis/build/builds/{id}/timeline):
  • reports at work-item level only, silently misses individual test failures. Always use the AzDO Test Results API via extract_failed_tests.py.
• Use powershell with requests for any direct API calls.

Allowed Tools

File I/O tools (view, edit, create, grep, glob) always allowed.

Rules

Extraction

• Every individual failure must be saved to test_results — this is the complete inventory. No failure may exist only in JSON output or in memory.
• Never skip failures — cross-check counts against AzDO summary. If results appear truncated, paginate until all are listed.
• Analyze every failing pipeline — never skip a pipeline or mark it as "needs investigation" or "expected same failures". Every pipeline must have confirmed findings from its own test results.
• If a pipeline/API call fails, log a warning and continue — never block the run.
• Use sub-agents for parallel failure extraction — delegate pipeline groups to separate general-purpose agents via the task tool. Pass the ADO_TOKEN to each sub-agent for AzDO Test Results API. Helix API needs no auth.
• Old failingSince builds may be purged (>90 days). Link to the latest failed build instead of generating a dead URL.
• AzDO Test Results API requires a bearer token — see Step 0 for how to obtain and set ADO_TOKEN. The token is valid ~60 minutes.
• AzDO Builds API and Helix API require NO authentication.

Triage

• Read the FULL console log file — do NOT read only the tail or a partial range.
• Classify using BOTH exit code AND error message — same exit code does NOT mean the same root cause.
• Do NOT group failures by exit code alone — read the actual error messages.
• For detailed triage workflow, see references/triage-workflow.md.
• For verbatim copy-paste rules, see references/verbatim-rules.md.

Bisect

• When bisecting, present evidence — don't guess.