ci: verify sccache MMDS reader boundary #1
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| name: sccache MMDS canary | |
| on: | |
| push: | |
| branches: | |
| - codex/sccache-mmds-canary | |
| permissions: | |
| contents: read | |
| jobs: | |
| verify-reader-boundary: | |
| runs-on: [self-hosted, fireactions-turbo] | |
| timeout-minutes: 5 | |
| steps: | |
| - name: Verify MMDSv2 and read-only R2 access | |
| shell: bash | |
| run: | | |
| set -euo pipefail | |
| python3 - <<'PY' | |
| import datetime | |
| import hashlib | |
| import hmac | |
| import json | |
| from urllib.error import HTTPError | |
| from urllib.parse import quote, urlsplit | |
| from urllib.request import Request, urlopen | |
| EXPECTED_ENDPOINT = "https://3dc4cebb791314d78848969042fb3382.r2.cloudflarestorage.com" | |
| EXPECTED_BUCKET = "subtensor-ci-sccache" | |
| EXPECTED_PREFIX = "subtensor/v1" | |
| PROBE_KEY = f"{EXPECTED_PREFIX}/verification/mmds-reader-canary.txt" | |
| PROBE_BODY = b"subtensor sccache MMDS reader canary\n" | |
| def mmds_metadata(): | |
| token_request = Request( | |
| "http://169.254.169.254/latest/api/token", | |
| method="PUT", | |
| headers={"X-Metadata-Token-TTL-Seconds": "60"}, | |
| ) | |
| with urlopen(token_request, timeout=5) as response: | |
| token = response.read().decode() | |
| metadata_request = Request( | |
| "http://169.254.169.254/latest/meta-data/sccache", | |
| headers={"X-Metadata-Token": token, "Accept": "application/json"}, | |
| ) | |
| with urlopen(metadata_request, timeout=5) as response: | |
| return json.loads(response.read()) | |
| def signing_key(secret, date_stamp, region, service): | |
| key_date = hmac.new(("AWS4" + secret).encode(), date_stamp.encode(), hashlib.sha256).digest() | |
| key_region = hmac.new(key_date, region.encode(), hashlib.sha256).digest() | |
| key_service = hmac.new(key_region, service.encode(), hashlib.sha256).digest() | |
| return hmac.new(key_service, b"aws4_request", hashlib.sha256).digest() | |
| def signed_request(method, url, access_key, secret_key, body=b""): | |
| parsed = urlsplit(url) | |
| now = datetime.datetime.now(datetime.timezone.utc) | |
| amz_date = now.strftime("%Y%m%dT%H%M%SZ") | |
| date_stamp = now.strftime("%Y%m%d") | |
| region = "auto" | |
| service = "s3" | |
| payload_hash = hashlib.sha256(body).hexdigest() | |
| canonical_uri = quote(parsed.path or "/", safe="/-_.~") | |
| canonical_query = parsed.query | |
| canonical_headers = ( | |
| f"host:{parsed.netloc}\n" | |
| f"x-amz-content-sha256:{payload_hash}\n" | |
| f"x-amz-date:{amz_date}\n" | |
| ) | |
| signed_headers = "host;x-amz-content-sha256;x-amz-date" | |
| canonical_request = "\n".join( | |
| [ | |
| method, | |
| canonical_uri, | |
| canonical_query, | |
| canonical_headers, | |
| signed_headers, | |
| payload_hash, | |
| ] | |
| ) | |
| algorithm = "AWS4-HMAC-SHA256" | |
| scope = f"{date_stamp}/{region}/{service}/aws4_request" | |
| string_to_sign = "\n".join( | |
| [algorithm, amz_date, scope, hashlib.sha256(canonical_request.encode()).hexdigest()] | |
| ) | |
| signature = hmac.new( | |
| signing_key(secret_key, date_stamp, region, service), | |
| string_to_sign.encode(), | |
| hashlib.sha256, | |
| ).hexdigest() | |
| authorization = ( | |
| f"{algorithm} Credential={access_key}/{scope}, " | |
| f"SignedHeaders={signed_headers}, Signature={signature}" | |
| ) | |
| request = Request( | |
| url, | |
| data=body if method in {"PUT", "POST"} else None, | |
| method=method, | |
| headers={ | |
| "Authorization": authorization, | |
| "Host": parsed.netloc, | |
| "X-Amz-Content-Sha256": payload_hash, | |
| "X-Amz-Date": amz_date, | |
| }, | |
| ) | |
| with urlopen(request, timeout=15) as response: | |
| return response.status, response.read() | |
| metadata = mmds_metadata() | |
| expected = { | |
| "bucket": EXPECTED_BUCKET, | |
| "endpoint": EXPECTED_ENDPOINT, | |
| "region": "auto", | |
| "s3_use_ssl": True, | |
| "s3_rw_mode": "READ_ONLY", | |
| "key_prefix": EXPECTED_PREFIX, | |
| } | |
| for key, value in expected.items(): | |
| if metadata.get(key) != value: | |
| raise RuntimeError(f"MMDS field {key!r} did not match the expected contract") | |
| access_key = metadata.get("access_key_id", "") | |
| secret_key = metadata.get("secret_access_key", "") | |
| if not access_key or not secret_key: | |
| raise RuntimeError("MMDS did not contain a complete reader credential") | |
| probe_url = f"{EXPECTED_ENDPOINT}/{EXPECTED_BUCKET}/{PROBE_KEY}" | |
| status, body = signed_request("GET", probe_url, access_key, secret_key) | |
| if status != 200 or body != PROBE_BODY: | |
| raise RuntimeError("R2 reader GET did not return the seeded probe") | |
| try: | |
| signed_request("PUT", probe_url + ".denied", access_key, secret_key, b"denied\n") | |
| except HTTPError as error: | |
| if error.code != 403: | |
| raise RuntimeError(f"R2 reader PUT failed with unexpected HTTP {error.code}") from error | |
| else: | |
| raise RuntimeError("R2 reader unexpectedly succeeded in writing an object") | |
| try: | |
| signed_request("DELETE", probe_url, access_key, secret_key) | |
| except HTTPError as error: | |
| if error.code != 403: | |
| raise RuntimeError(f"R2 reader DELETE failed with unexpected HTTP {error.code}") from error | |
| else: | |
| raise RuntimeError("R2 reader unexpectedly succeeded in deleting an object") | |
| print("MMDSv2 contract: PASS") | |
| print("R2 reader GET: PASS") | |
| print("R2 reader PUT/DELETE denied: PASS") | |
| PY |