api: provide /metrics for prometheus export

Instead of inventing a new stats API, use a Prometheus compatible
backend. This commits removes all /api/v1/stats calls and instead
provides everything interesting over at /metrics.

A single metric `builds` is provided with a bunch of tags. Those tags
can be used to create graphs describing which branch/version/profile etc
was build.

While at it, switch testing to use a sync build queue, meaning jobs will
actually run and don't just end up in a "202 ACCEPTED" state.

No longer validate outgoing messages except during testing to speed up
the server.

Signed-off-by: Paul Spooren <mail@aparcar.org>

Author: aparcar

asu/api.py

@@ -4,7 +4,7 @@
 from rq import Connection, Queue
 
 from .build import build
-from .common import get_request_hash, stats_profiles, stats_versions
+from .common import get_request_hash
 
 bp = Blueprint("api", __name__, url_prefix="/api")
 
@@ -37,7 +37,9 @@ def get_queue() -> Queue:
     """
     if "queue" not in g:
         with Connection():
-            g.queue = Queue(connection=get_redis())
+            g.queue = Queue(
+                connection=get_redis(), is_async=current_app.config["ASYNC_QUEUE"]
+            )
     return g.queue
 
 
@@ -57,77 +59,6 @@ def api_latest():
     return redirect("/json/v1/latest.json")
 
 
-def api_v1_stats_images():
-    return jsonify(
-        {
-            "total": int((get_redis().get("stats-images") or b"0").decode("utf-8")),
-            "custom": int(
-                (get_redis().get("stats-images-custom") or b"0").decode("utf-8")
-            ),
-        }
-    )
-
-
-def api_v1_stats_versions():
-    return jsonify({"versions": stats_versions()})
-
-
-def api_v1_stats_targets(branch="SNAPSHOT"):
-    if branch not in current_app.config["BRANCHES"]:
-        return "", 404
-
-    return jsonify(
-        {
-            "branch": branch,
-            "targets": [
-                (s, p.decode("utf-8"))
-                for p, s in get_redis().zrevrange(
-                    f"stats-targets-{branch}", 0, -1, withscores=True
-                )
-            ],
-        }
-    )
-
-
-@bp.route("/v1/stats/targets/")
-def api_v1_stats_targets_default():
-    return redirect("/api/v1/stats/targets/SNAPSHOT")
-
-
-def api_v1_stats_packages(branch="SNAPSHOT"):
-    if branch not in current_app.config["BRANCHES"]:
-        return "", 404
-
-    return jsonify(
-        {
-            "branch": branch,
-            "packages": [
-                (s, p.decode("utf-8"))
-                for p, s in get_redis().zrevrange(
-                    f"stats-packages-{branch}", 0, -1, withscores=True
-                )
-            ],
-        }
-    )
-
-
-@bp.route("/v1/stats/packages/")
-def api_v1_stats_packages_default():
-    return redirect("/api/v1/stats/packages/SNAPSHOT")
-
-
-def api_v1_stats_profiles(branch):
-    if branch not in current_app.config["BRANCHES"]:
-        return "", 404
-
-    return jsonify({"branch": branch, "profiles": stats_profiles(branch)})
-
-
-@bp.route("/v1/stats/profiles/")
-def api_v1_stats_profiles_default():
-    return redirect("/api/v1/stats/profiles/SNAPSHOT")
-
-
 def validate_packages(req):
     if req.get("packages_versions") and not req.get("packages"):
         req["packages"] = req["packages_versions"].keys()
@@ -188,7 +119,7 @@ def validate_request(req):
 
     if "defaults" in req and not current_app.config["ALLOW_DEFAULTS"]:
         return (
-            {"detail": f"Handling `defaults` not enabled on server", "status": 400},
+            {"detail": "Handling `defaults` not enabled on server", "status": 400},
             400,
         )
 
@@ -272,7 +203,7 @@ def return_job_v1(job):
         response.update(job.meta)
 
     if job.is_failed:
-        response.update({"status": 500, "detail": job.exc_info.strip().split("\n")[-1]})
+        response.update({"status": 500})
 
     elif job.is_queued:
         response.update(
@@ -294,11 +225,13 @@ def return_job_v1(job):
         headers = {"X-Imagebuilder-Status": response.get("imagebuilder_status", "init")}
 
     elif job.is_finished:
-        response.update({"status": 200, "build_at": job.ended_at, **job.result})
+        response.update({"status": 200, **job.result})
 
     response["enqueued_at"] = job.enqueued_at
     response["request_hash"] = job.id
 
+    print(response)
+
     current_app.logger.debug(response)
     return response, response["status"], headers
 
@@ -367,7 +300,7 @@ def return_job(job):
     status = 500
 
     if job.is_failed:
-        response["message"] = job.exc_info.strip().split("\n")[-1]
+        response["message"] = job.meta["detail"]
 
     elif job.is_queued:
         status = 202

asu/asu.py

@@ -1,10 +1,14 @@
 import json
+
+# from msilib.schema import Registry
 from os import getenv
 from pathlib import Path
 
 import connexion
-from flask import Flask, redirect, render_template, send_from_directory
+from flask import Flask, render_template, send_from_directory
+from prometheus_client import CollectorRegistry, make_wsgi_app
 from redis import Redis
+from werkzeug.middleware.dispatcher import DispatcherMiddleware
 
 import asu.common
 from asu import __version__
@@ -26,6 +30,7 @@ def create_app(test_config: dict = None) -> Flask:
 
     cnxn = connexion.FlaskApp(__name__)
     app = cnxn.app
+
     app.config.from_mapping(
         JSON_PATH=Path.cwd() / "public/json/v1/",
         REDIS_CONN=Redis(host=redis_host, port=redis_port, password=redis_password),
@@ -34,6 +39,7 @@ def create_app(test_config: dict = None) -> Flask:
         UPSTREAM_URL="https://downloads.openwrt.org",
         BRANCHES={},
         ALLOW_DEFAULTS=False,
+        ASYNC_QUEUE=True,
     )
 
     if not test_config:
@@ -45,6 +51,7 @@ def create_app(test_config: dict = None) -> Flask:
                 print(f"Loading {config_file}")
                 app.config.from_pyfile(config_file)
                 break
+        app.config["REGISTRY"] = CollectorRegistry()
     else:
         app.config.from_mapping(test_config)
 
@@ -53,6 +60,10 @@ def create_app(test_config: dict = None) -> Flask:
             app.config[option] = Path(value)
             app.config[option].mkdir(parents=True, exist_ok=True)
 
+    app.wsgi_app = DispatcherMiddleware(
+        app.wsgi_app, {"/metrics": make_wsgi_app(app.config["REGISTRY"])}
+    )
+
     (Path().cwd()).mkdir(exist_ok=True, parents=True)
 
     @app.route("/json/")
@@ -74,6 +85,10 @@ def store_path(path="index.html"):
 
     app.register_blueprint(api.bp)
 
+    from . import metrics
+
+    app.config["REGISTRY"].register(metrics.BuildCollector(app.config["REDIS_CONN"]))
+
     branches = dict(
         map(
             lambda b: (b["name"], b),
@@ -142,6 +157,6 @@ def stats():
         if not app.config["REDIS_CONN"].hexists("mapping-abi", package):
             app.config["REDIS_CONN"].hset("mapping-abi", package, source)
 
-    cnxn.add_api("openapi.yml", validate_responses=True)
+    cnxn.add_api("openapi.yml", validate_responses=app.config["TESTING"])
 
     return app