feat(reliability) Add /live and /ready probes (#90)

Author: bplatak

.github/actions/python-poetry/action.yml

@@ -9,7 +9,7 @@ inputs:
   poetry-version:
     required: false
     description: Poetry version
-    default: "1.2.2"
+    default: "2.1.4"
 
 runs:
   using: composite

.github/workflows/build-and-push-image.yaml

@@ -16,7 +16,7 @@ jobs:
     steps:
       - uses: actions/checkout@v2
       - uses: ./.github/actions/python-poetry
-      - uses: pre-commit/action@v2.0.3
+      - uses: pre-commit/action@v3.0.1
 
   run-tests:
     runs-on: ubuntu-latest

.gitignore

@@ -1,10 +1,12 @@
 __pycache__/
 *.py[cod]
 *$py.class
+poetry.toml
 
 .DS_Store
 .envrc
 .coverage
 
 .env
-.vscode/
+.vscode/
+.idea/

.python-version

@@ -1 +1 @@
-3.10
+3.11

Dockerfile

@@ -3,14 +3,14 @@
 ARG APP_NAME=pyth-observer
 ARG APP_PACKAGE=pyth_observer
 ARG APP_PATH=/opt/$APP_NAME
-ARG PYTHON_VERSION=3.10.4
-ARG POETRY_VERSION=1.2.2
+ARG PYTHON_VERSION=3.11
+ARG POETRY_VERSION=2.1.4
 
 #
 # Stage: base
 #
 
-FROM python:$PYTHON_VERSION as base
+FROM python:$PYTHON_VERSION AS base
 
 ARG APP_NAME
 ARG APP_PATH
@@ -27,8 +27,9 @@ ENV \
     POETRY_NO_INTERACTION=1
 
 # Install Poetry - respects $POETRY_VERSION & $POETRY_HOME
-RUN curl -sSL https://install.python-poetry.org | python
+RUN curl -sSL https://install.python-poetry.org | python - --version $POETRY_VERSION
 ENV PATH="$POETRY_HOME/bin:$PATH"
+RUN which poetry && poetry --version
 
 WORKDIR $APP_PATH
 COPY . .
@@ -37,7 +38,7 @@ COPY . .
 # Stage: development
 #
 
-FROM base as development
+FROM base AS development
 
 ARG APP_NAME
 ARG APP_PATH
@@ -54,20 +55,21 @@ CMD ["$APP_NAME"]
 # Stage: build
 #
 
-FROM base as build
+FROM base AS build
 
 ARG APP_NAME
 ARG APP_PATH
 
 WORKDIR $APP_PATH
 RUN poetry build --format wheel
+RUN poetry self add poetry-plugin-export
 RUN poetry export --format requirements.txt --output constraints.txt --without-hashes
 
 #
 # Stage: production
 #
 
-FROM python:$PYTHON_VERSION as production
+FROM python:$PYTHON_VERSION AS production
 
 ARG APP_NAME
 ARG APP_PATH

README.md

@@ -61,3 +61,11 @@ To integrate Telegram events with the Observer, you need the Telegram group chat
 
 Use this ID in the `publishers.yaml` configuration to correctly set up Telegram events.
 
+## Health Endpoints
+
+The Observer exposes HTTP endpoints for health checks, suitable for Kubernetes liveness and readiness probes:
+
+- **Liveness probe**: `GET /live` always returns `200 OK` with body `OK`.
+- **Readiness probe**: `GET /ready` returns `200 OK` with body `OK` if the observer is ready, otherwise returns `503 Not Ready`.
+
+By default, these endpoints are served on port 8080. You can use them in your Kubernetes deployment to monitor the application's health.

poetry.lock

@@ -1,10 +1,10 @@
 [tool.mypy]
-python_version = "3.10"
+python_version = "3.11"
 ignore_missing_imports = true
 
 [tool.poetry]
 name = "pyth-observer"
-version = "0.3.5"
+version = "2.1.4"
 description = "Alerts and stuff"
 authors = []
 readme = "README.md"
@@ -28,6 +28,7 @@ types-pyyaml = "^6.0.12"
 types-pytz = "^2022.4.0.0"
 python-dotenv = "^1.0.1"
 numpy = "^2.1.3"
+cffi = "^1.17"
 
 
 [tool.poetry.group.dev.dependencies]
@@ -47,3 +48,6 @@ pyth-observer = "pyth_observer.cli:run"
 [build-system]
 requires = ["poetry-core"]
 build-backend = "poetry.core.masonry.api"
+
+[tool.poetry.requires-plugins]
+poetry-plugin-export = ">=1.8"

pyproject.toml

@@ -17,6 +17,7 @@
 )
 from throttler import Throttler
 
+import pyth_observer.health_server as health_server
 from pyth_observer.check.price_feed import PriceFeedState
 from pyth_observer.check.publisher import PublisherState
 from pyth_observer.coingecko import Symbol, get_coingecko_prices
@@ -72,98 +73,106 @@ def __init__(
 
     async def run(self):
         while True:
-            logger.info("Running checks")
-
-            products = await self.get_pyth_products()
-            coingecko_prices, coingecko_updates = await self.get_coingecko_prices()
-            crosschain_prices = await self.get_crosschain_prices()
-
-            for product in products:
-                # Skip tombstone accounts with blank metadata
-                if "base" not in product.attrs:
-                    continue
-
-                if not product.first_price_account_key:
-                    continue
-
-                # For each product, we build a list of price feed states (one
-                # for each price account) and a list of publisher states (one
-                # for each publisher).
-                states = []
-                price_accounts = await self.get_pyth_prices(product)
-
-                crosschain_price = crosschain_prices.get(
-                    b58decode(product.first_price_account_key.key).hex(), None
-                )
-
-                for _, price_account in price_accounts.items():
-                    # Handle potential None for min_publishers
-                    if (
-                        price_account.min_publishers is None
-                        # When min_publishers is high it means that the price is not production-ready
-                        # yet and it is still being tested. We need no alerting for these prices.
-                        or price_account.min_publishers >= 10
-                    ):
+            try:
+                logger.info("Running checks")
+
+                products = await self.get_pyth_products()
+                coingecko_prices, coingecko_updates = await self.get_coingecko_prices()
+                crosschain_prices = await self.get_crosschain_prices()
+
+                health_server.observer_ready = True
+
+                for product in products:
+                    # Skip tombstone accounts with blank metadata
+                    if "base" not in product.attrs:
+                        continue
+
+                    if not product.first_price_account_key:
                         continue
 
-                    # Ensure latest_block_slot is not None or provide a default value
-                    latest_block_slot = (
-                        price_account.slot if price_account.slot is not None else -1
+                    # For each product, we build a list of price feed states (one
+                    # for each price account) and a list of publisher states (one
+                    # for each publisher).
+                    states = []
+                    price_accounts = await self.get_pyth_prices(product)
+
+                    crosschain_price = crosschain_prices.get(
+                        b58decode(product.first_price_account_key.key).hex(), None
                     )
 
-                    if not price_account.aggregate_price_status:
-                        raise RuntimeError("Price account status is missing")
-
-                    if not price_account.aggregate_price_info:
-                        raise RuntimeError("Aggregate price info is missing")
-
-                    states.append(
-                        PriceFeedState(
-                            symbol=product.attrs["symbol"],
-                            asset_type=product.attrs["asset_type"],
-                            schedule=MarketSchedule(product.attrs["schedule"]),
-                            public_key=price_account.key,
-                            status=price_account.aggregate_price_status,
-                            # this is the solana block slot when price account was fetched
-                            latest_block_slot=latest_block_slot,
-                            latest_trading_slot=price_account.last_slot,
-                            price_aggregate=price_account.aggregate_price_info.price,
-                            confidence_interval_aggregate=price_account.aggregate_price_info.confidence_interval,
-                            coingecko_price=coingecko_prices.get(product.attrs["base"]),
-                            coingecko_update=coingecko_updates.get(
-                                product.attrs["base"]
-                            ),
-                            crosschain_price=crosschain_price,
+                    for _, price_account in price_accounts.items():
+                        # Handle potential None for min_publishers
+                        if (
+                            price_account.min_publishers is None
+                            # When min_publishers is high it means that the price is not production-ready
+                            # yet and it is still being tested. We need no alerting for these prices.
+                            or price_account.min_publishers >= 10
+                        ):
+                            continue
+
+                        # Ensure latest_block_slot is not None or provide a default value
+                        latest_block_slot = (
+                            price_account.slot if price_account.slot is not None else -1
                         )
-                    )
 
-                    for component in price_account.price_components:
-                        pub = self.publishers.get(component.publisher_key.key, None)
-                        publisher_name = (
-                            (pub.name if pub else "")
-                            + f" ({component.publisher_key.key})"
-                        ).strip()
+                        if not price_account.aggregate_price_status:
+                            raise RuntimeError("Price account status is missing")
+
+                        if not price_account.aggregate_price_info:
+                            raise RuntimeError("Aggregate price info is missing")
+
                         states.append(
-                            PublisherState(
-                                publisher_name=publisher_name,
+                            PriceFeedState(
                                 symbol=product.attrs["symbol"],
                                 asset_type=product.attrs["asset_type"],
                                 schedule=MarketSchedule(product.attrs["schedule"]),
-                                public_key=component.publisher_key,
-                                confidence_interval=component.latest_price_info.confidence_interval,
-                                confidence_interval_aggregate=price_account.aggregate_price_info.confidence_interval,
-                                price=component.latest_price_info.price,
-                                price_aggregate=price_account.aggregate_price_info.price,
-                                slot=component.latest_price_info.pub_slot,
-                                aggregate_slot=price_account.last_slot,
+                                public_key=price_account.key,
+                                status=price_account.aggregate_price_status,
                                 # this is the solana block slot when price account was fetched
                                 latest_block_slot=latest_block_slot,
-                                status=component.latest_price_info.price_status,
-                                aggregate_status=price_account.aggregate_price_status,
+                                latest_trading_slot=price_account.last_slot,
+                                price_aggregate=price_account.aggregate_price_info.price,
+                                confidence_interval_aggregate=price_account.aggregate_price_info.confidence_interval,
+                                coingecko_price=coingecko_prices.get(
+                                    product.attrs["base"]
+                                ),
+                                coingecko_update=coingecko_updates.get(
+                                    product.attrs["base"]
+                                ),
+                                crosschain_price=crosschain_price,
                             )
                         )
 
-                await self.dispatch.run(states)
+                        for component in price_account.price_components:
+                            pub = self.publishers.get(component.publisher_key.key, None)
+                            publisher_name = (
+                                (pub.name if pub else "")
+                                + f" ({component.publisher_key.key})"
+                            ).strip()
+                            states.append(
+                                PublisherState(
+                                    publisher_name=publisher_name,
+                                    symbol=product.attrs["symbol"],
+                                    asset_type=product.attrs["asset_type"],
+                                    schedule=MarketSchedule(product.attrs["schedule"]),
+                                    public_key=component.publisher_key,
+                                    confidence_interval=component.latest_price_info.confidence_interval,
+                                    confidence_interval_aggregate=price_account.aggregate_price_info.confidence_interval,
+                                    price=component.latest_price_info.price,
+                                    price_aggregate=price_account.aggregate_price_info.price,
+                                    slot=component.latest_price_info.pub_slot,
+                                    aggregate_slot=price_account.last_slot,
+                                    # this is the solana block slot when price account was fetched
+                                    latest_block_slot=latest_block_slot,
+                                    status=component.latest_price_info.price_status,
+                                    aggregate_status=price_account.aggregate_price_status,
+                                )
+                            )
+
+                    await self.dispatch.run(states)
+            except Exception as e:
+                logger.error(f"Error in run loop: {e}")
+                health_server.observer_ready = False
 
             logger.debug("Sleeping...")
             await asyncio.sleep(5)

pyth_observer/__init__.py

@@ -8,6 +8,7 @@
 from prometheus_client import start_http_server
 
 from pyth_observer import Observer, Publisher
+from pyth_observer.health_server import start_health_server
 from pyth_observer.models import ContactInfo
 
 
@@ -61,7 +62,11 @@ def run(config, publishers, coingecko_mapping, prometheus_port):
 
     start_http_server(int(prometheus_port))
 
-    asyncio.run(observer.run())
+    async def main():
+        asyncio.create_task(start_health_server())
+        await observer.run()
+
+    asyncio.run(main())
 
 
 logger.remove()