Working watchdog

Makefile

@@ -10,8 +10,8 @@ build-m1:
 rebuild:
 	docker build --no-cache --tag opentopodata:$(VERSION) --file docker/Dockerfile .
 
-rebuild-m1-no-cache:
-	docker build --tag opentopodata:$(VERSION) --file docker/apple-silicon.Dockerfile .
+rebuild-m1:
+	docker build --no-cache --tag opentopodata:$(VERSION) --file docker/apple-silicon.Dockerfile .
 
 run:
 	docker run --rm -it --volume "$(shell pwd)/data:/app/data:ro" -p 5000:5000 opentopodata:$(VERSION) 
@@ -29,7 +29,7 @@ run-local:
 	FLASK_APP=opentopodata/api.py FLASK_DEBUG=1 flask run --port 5000
 
 black:
-	black --target-version py311 tests opentopodata
+	black --target-version py311 tests opentopodata docker
 
 black-check:
 	docker run --rm opentopodata:$(VERSION) python -m black --check --target-version py311 tests opentopodata

docker/Dockerfile

@@ -15,6 +15,8 @@ FROM python:3.11.10-slim-bookworm
 RUN set -e && \
     apt-get update && \
     apt-get install -y --no-install-recommends \
+        inotify-tools \
+        nano \
         nginx \
         memcached \
         supervisor && \

docker/config_watcher.py

@@ -0,0 +1,110 @@
+import logging
+import time
+from pathlib import Path
+import subprocess
+import sys
+
+from watchdog.observers import Observer
+from watchdog.events import FileSystemEventHandler
+
+
+# Paths.
+CONFIG_DIR = Path("/app/")
+CONFIG_PATH = Path("/app/config.yaml")
+EXAMPLE_CONFIG_PATH = Path("/app/example-config.yaml")
+
+# Debouncing: once the config has been reloaded, any queued unprocessed events should be discarded.
+LAST_INVOCATION_TIME = time.time()
+
+
+# Logger setup.
+logger = logging.getLogger("configwatcher")
+LOG_FORMAT = "%(asctime)s %(levelname)-8s %(message)s"
+formatter = logging.Formatter(LOG_FORMAT)
+logger.setLevel(logging.INFO)
+handler = logging.StreamHandler(sys.stdout)
+handler.setLevel(logging.INFO)
+handler.setFormatter(formatter)
+logger.addHandler(handler)
+
+
+def run_cmd(cmd, shell=False):
+    r = subprocess.run(cmd, shell=shell, capture_output=True)
+    is_error = r.returncode != 0
+    stdout = r.stdout.decode("utf-8")
+    if is_error:
+        logger.error(f"Error running command, returncode: {r.returncode}")
+        logger.error("cmd:")
+        logger.error(" ".join(cmd))
+        if r.stdout:
+            logger.error("stdout:")
+            logger.error(stdout)
+        if r.stderr:
+            logger.error("stderr:")
+            logger.error(r.stderr.decode("utf-8"))
+        raise ValueError
+    return stdout
+
+
+def reload_config():
+    global LAST_INVOCATION_TIME
+    LAST_INVOCATION_TIME = time.time()
+    logger.info("Restarting OTD due to config change.")
+    run_cmd(["supervisorctl", "-c", "/app/docker/supervisord.conf", "stop", "uwsgi"])
+    run_cmd(
+        ["supervisorctl", "-c", "/app/docker/supervisord.conf", "restart", "memcached"]
+    )
+    run_cmd(["supervisorctl", "-c", "/app/docker/supervisord.conf", "start", "uwsgi"])
+    run_cmd(
+        ["supervisorctl", "-c", "/app/docker/supervisord.conf", "start", "warm_cache"]
+    )
+    LAST_INVOCATION_TIME = time.time()
+    logger.info("Restarted OTD due to config change.")
+
+
+class Handler(FileSystemEventHandler):
+
+    def on_any_event(self, event):
+        watch_paths_str = [
+            EXAMPLE_CONFIG_PATH.as_posix(),
+            CONFIG_PATH.as_posix(),
+        ]
+
+        # Filter unwanted events.
+        if event.event_type not in {"modified", "created"}:
+            logger.info(f"Dropping event with type {event.event_type=}")
+            return
+        if event.is_directory:
+            logger.info(f"Dropping dir event")
+            return
+        if event.src_path not in watch_paths_str:
+            logger.info(f"Dropping event with path {event.src_path=}")
+            return
+        if not Path(event.src_path).exists():
+            logger.info(f"Dropping event for nonexistent path {event.src_path=}")
+            return
+
+        # Debouncing.
+        mtime = Path(event.src_path).lstat().st_mtime
+        if mtime < LAST_INVOCATION_TIME:
+            msg = f"Dropping event for file that hasn't been modified since the last run. {event.src_path=}"
+            logger.info(msg)
+            return
+
+        logger.info(f"Dispatching event on {event.src_path=}")
+        reload_config()
+
+
+if __name__ == "__main__":
+
+    event_handler = Handler()
+    observer = Observer()
+    observer.schedule(event_handler, CONFIG_DIR, recursive=False)
+    observer.start()
+
+    try:
+        while True:
+            time.sleep(1)
+    finally:
+        observer.stop()
+        observer.join()

docker/supervisord.conf

@@ -2,6 +2,19 @@
 nodaemon=true
 user=root
 
+
+# Supervisorctl config/
+[unix_http_server]
+file=/var/run/supervisor.sock
+chmod=0700
+[rpcinterface:supervisor]
+supervisor.rpcinterface_factory = supervisor.rpcinterface:make_main_rpcinterface
+[supervisorctl]
+serverurl=unix:///var/run/supervisor.sock
+
+
+# OTD services.
+
 [program:uwsgi]
 command=/usr/local/bin/uwsgi --ini /app/docker/uwsgi.ini --processes %(ENV_N_UWSGI_THREADS)s
 stdout_logfile=/dev/stdout
@@ -33,10 +46,9 @@ stderr_logfile=/dev/stderr
 stderr_logfile_maxbytes=0
 autorestart=false
 
-[program:watchdog]
-command=python /app/docker/watcher.py
+[program:watch_config]
+command=python /app/docker/config_watcher.py
 stdout_logfile=/dev/stdout
 stdout_logfile_maxbytes=0
 stderr_logfile=/dev/stderr
-stderr_logfile_maxbytes=0
-
+stderr_logfile_maxbytes=0

docker/warm_cache.py

@@ -34,5 +34,7 @@
         break
 
     else:
-        logging.error("Timeout while trying to pre-populate the cache. This probably means that Open Topo Data isn't working.")
+        logging.error(
+            "Timeout while trying to pre-populate the cache. This probably means that Open Topo Data isn't working."
+        )
         sys.exit(1)

example-config.yaml

@@ -1,5 +1,5 @@
 # An example of a config.yaml file showing all possible options. If no
-# config.yaml file exists, opentopodata will load example-config.yaml instead.
+# config.yaml file exists, opentopodata will load example-config.yaml instead..
 
 
 # 400 error will be thrown above this limit.

requirements.in

@@ -13,5 +13,4 @@ pytest-timeout
 PyYAML
 rasterio>=1.3.8,<1.4.0  # 1.3.8+ avoids memory leak https://github.com/ajnisbet/opentopodata/issues/68; 1.4.0 introduces some bugs in rowcol/xy (as of 2024-10-11).
 requests
-watchdog # Monitor changes on the config.yaml
-pymemcache # Handle cache flushing without messing
+watchdog

requirements.txt

@@ -81,14 +81,10 @@ polyline==2.0.2
     # via -r requirements.in
 pylibmc==1.6.3
     # via -r requirements.in
-
-pymemcache==4.0.0
-    # via -r requirements.in
 pyparsing==3.1.4
-    # via rasterio
+    # via snuggs
 pyproj==3.7.0
     # via -r requirements.in
-
 pyproject-hooks==1.2.0
     # via
     #   build
@@ -104,15 +100,16 @@ pytest-timeout==2.3.1
     # via -r requirements.in
 pyyaml==6.0.2
     # via -r requirements.in
-rasterio==1.4.1
+rasterio==1.3.11
     # via -r requirements.in
 requests==2.32.3
     # via -r requirements.in
+snuggs==1.4.7
+    # via rasterio
 urllib3==2.2.3
     # via requests
 watchdog==5.0.3
     # via -r requirements.in
-
 werkzeug==3.0.4
     # via flask
 wheel==0.44.0