Wiring up the printer control machinery

projects/tentacles/BUILD

@@ -7,6 +7,7 @@ py_project(
         py_requirement("click"),
         py_requirement("flask"),
         py_requirement("jinja2"),
+        py_requirement("octorest"),
     ],
     main_data = [
         "//projects/tentacles/src/python/tentacles/static/css",

projects/tentacles/src/python/tentacles/__main__.py

@@ -1,18 +1,17 @@
 #!/usr/bin/env python3
 
-"""
+"""The core app entrypoint."""
-
-"""
 
 from pathlib import Path
 import click
-from flask import Flask, request, current_app
+from flask import Flask, request
 import tomllib
 from datetime import datetime
 
 from tentacles.blueprints import user_ui, printer_ui, api
 from tentacles.store import Store
 from tentacles.globals import _ctx, Ctx, ctx
+from tentacles.workers import create_workers
 
 
 @click.group()
@@ -20,10 +19,15 @@ def cli():
     pass
 
 
+def store_factory(app):
+    store = Store(app.config.get("db", {}).get("uri"))
+    store.connect()
+    return store
+
+
 def custom_ctx(app, wsgi_app):
     def helper(environ, start_response):
-        store = Store(app.config.get("db", {}).get("uri"))
+        store = store_factory(app)
-        store.connect()
         token = _ctx.set(Ctx(store))
         try:
             return wsgi_app(environ, start_response)
@@ -34,10 +38,10 @@ def custom_ctx(app, wsgi_app):
     return helper
 
 
-def create_j2_request_global():
+def create_j2_request_global(app):
-    current_app.jinja_env.globals["ctx"] = ctx
+    app.jinja_env.globals["ctx"] = ctx
-    current_app.jinja_env.globals["request"] = request
+    app.jinja_env.globals["request"] = request
-    current_app.jinja_env.globals["datetime"] = datetime
+    app.jinja_env.globals["datetime"] = datetime
 
 
 def user_session():
@@ -65,8 +69,8 @@ def serve(hostname: str, port: int, config: Path):
     print(app.config)
 
     # Before first request
-    with app.app_context():
+    create_j2_request_global(app)
-        create_j2_request_global()
+    shutdown_event = create_workers(lambda: store_factory(app))
 
     # Before request
     app.before_request(user_session)
@@ -80,7 +84,10 @@ def serve(hostname: str, port: int, config: Path):
     app.wsgi_app = custom_ctx(app, app.wsgi_app)
 
     # And run the blame thing
-    app.run(host=hostname, port=port)
+    try:
+        app.run(host=hostname, port=port)
+    finally:
+        shutdown_event.set()
 
 
 if __name__ == "__main__":

projects/tentacles/src/python/tentacles/schema.sql

@@ -14,9 +14,9 @@ CREATE TABLE IF NOT EXISTS user_statuses (
  , UNIQUE(name)
 );
 
-INSERT OR IGNORE INTO user_statuses (id, name) values (-1, 'disabled');
+INSERT OR IGNORE INTO user_statuses (id, name) VALUES (-1, 'disabled');
-INSERT OR IGNORE INTO user_statuses (id, name) values (-2, 'unverified');
+INSERT OR IGNORE INTO user_statuses (id, name) VALUES (-2, 'unverified');
-INSERT OR IGNORE INTO user_statuses (id, name) values (1, 'enabled');
+INSERT OR IGNORE INTO user_statuses (id, name) VALUES (1, 'enabled');
 
 CREATE TABLE IF NOT EXISTS users (
    id INTEGER PRIMARY KEY AUTOINCREMENT

projects/tentacles/src/python/tentacles/static/css/_tirefire.scss

@@ -135,13 +135,14 @@ $secondary_dark_grey: #9A9A9A;
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////
 // A timer animation
+
 .timer {
     background: -webkit-linear-gradient(left, skyBlue 50%, #eee 50%);
     border-radius: 100%;
     height: calc(var(--size) * 1px);
     width: calc(var(--size) * 1px);
     position: relative;
-    -webkit-animation: time calc(var(--duration) * 1s) steps(1000, start) infinite;
+    -webkit-animation: time calc(var(--duration) * 1s) steps(1000, start);
       -webkit-mask: radial-gradient(transparent 50%,#000 50%);
       mask: radial-gradient(transparent 50%,#000 50%);
 }
@@ -152,7 +153,7 @@ $secondary_dark_grey: #9A9A9A;
     position: absolute;
     top: 0;
     width: 50%;
-    -webkit-animation: mask calc(var(--duration) * 1s) steps(500, start) infinite;
+    -webkit-animation: mask calc(var(--duration) * 1s) steps(500, start);
     -webkit-transform-origin: 100% 50%;
 }
 @-webkit-keyframes time {
@@ -178,3 +179,10 @@ $secondary_dark_grey: #9A9A9A;
         -webkit-transform: rotate(-180deg);
     }
 }
+
+.alert .timer {
+    --size: 10;
+    --duration: 5;
+    padding: 6px;
+    margin: 6px;
+}

projects/tentacles/src/python/tentacles/store.py

@@ -242,15 +242,53 @@ class Store(object):
             [name, url, api_key],
         ).fetchone()
 
+    @requires_conn
+    def fetch_printer(self, printer_id: int):
+        return self._conn.execute(
+            """
+            SELECT
+               p.id
+             , p.name
+             , p.url
+             , p.api_key
+             , p.last_poll_date
+             , s.name as status
+            FROM printers p
+            INNER JOIN printer_statuses s
+            ON p.status_id = s.id
+            WHERE p.id = ?1
+            """,
+            [printer_id],
+        ).fetchone()
+
     @requires_conn
     def list_printers(self):
         return self._conn.execute(
-            "SELECT p.id, p.name, p.url, p.last_poll_date, s.name as status FROM printers p INNER JOIN printer_statuses s ON p.status_id = s.id"
+            "SELECT p.id, p.name, p.url, p.api_key, p.last_poll_date, s.name as status FROM printers p INNER JOIN printer_statuses s ON p.status_id = s.id"
+        ).fetchall()
+
+    @fmap(one)
+    @requires_conn
+    def list_idle_printers(self):
+        return self._conn.execute(
+            """
+            SELECT p.id
+            FROM printers p
+            LEFT JOIN jobs j ON p.id = j.printer_id
+            WHERE j.id IS NULL
+            """
         ).fetchall()
 
     @requires_conn
-    def update_printer_status(self, printer_id, status_id):
+    def update_printer_status(self, printer_id, state: str):
-        pass
+        (status_id,) = self._conn.execute(
+            "SELECT id FROM printer_statuses WHERE name = ?1", [state]
+        ).fetchone()
+
+        self._conn.execute(
+            "UPDATE printers SET status_id = ?2, last_poll_date = datetime('now') WHERE id = ?1",
+            [printer_id, status_id],
+        )
 
     ################################################################################
     # Files
@@ -274,6 +312,10 @@ class Store(object):
     def delete_file(self, uid: int, fid: int):
         self._conn.execute("DELETE FROM files WHERE user_id = ? AND id = ?", [uid, fid])
 
+    @requires_conn
+    def fetch_file(self, fid: int):
+        return self._conn.execute("SELECT * FROM files WHERE id = ?", [fid]).fetchone()
+
     ################################################################################
     # Job
     #
@@ -301,10 +343,40 @@ class Store(object):
         """Enumerate jobs in priority order."""
         cond = f"AND user_id = {uid}" if uid else ""
         return self._conn.execute(
-            f"SELECT * FROM jobs WHERE started_at IS NULL {cond} ORDER BY priority DESC",
+            f"""
+            SELECT * FROM jobs
+            WHERE started_at IS NULL AND printer_id IS NULL {cond}
+            ORDER BY priority DESC
+            """,
             [],
         ).fetchall()
 
+    @requires_conn
+    def list_mapped_jobs(self):
+        """Scheduler detail. List mapped but not started jobs."""
+
+        return self._conn.execute(
+            """
+            SELECT * FROM jobs
+            WHERE started_at IS NULL AND printer_id IS NOT NULL
+            ORDER BY priority DESC
+            """,
+            [],
+        ).fetchall()
+
+    @requires_conn
+    def poll_job_queue(self):
+        return self._conn.execute(
+            """
+            SELECT id
+            FROM jobs
+            WHERE started_at IS NULL
+                  AND printer_id IS NULL
+            ORDER BY priority DESC
+            LIMIT 1
+            """
+        ).fetchone()
+
     @requires_conn
     def fetch_job(self, uid: int, jid: int) -> Optional[tuple]:
         return self._conn.execute(
@@ -312,21 +384,15 @@ class Store(object):
         ).fetchone()
 
     @requires_conn
-    def alter_job(self, job: tuple):
+    def assign_job(self, job_id: int, printer_id: int):
-        fields = [
-            "id",
-            "user_id",
-            "file_id",
-            "priority",
-            "started_at",
-            "finished_at",
-            "state",
-            "printer_id",
-        ]
-        assert len(job) == len(fields)
         return self._conn.execute(
-            f"INSERT OR REPLACE INTO jobs ({', '.join(fields)}) VALUES ({', '.join(['?'] * len(fields))})",
+            "UPDATE jobs SET printer_id = ?2 WHERE id = ?1", [job_id, printer_id]
-            job,
+        )
+
+    @requires_conn
+    def start_job(self, job_id: int):
+        return self._conn.execute(
+            "UPDATE jobs SET started_at = datetime('now') WHERE id = ?1", [job_id]
         )
 
     @requires_conn

projects/tentacles/src/python/tentacles/templates/base.html.j2

@@ -44,9 +44,9 @@
     <div class="flashes">
       {% for category, message in messages %}
         <div class="alert {{ category }}">
-          <input type="checkbox" id="alert{{ loop.index }}"/>
+          <input type="checkbox" id="alert{{ loop.index }}" />
           <label class="close" title="close" for="alert{{loop.index}}">
-            <div class="paused-timer" style="--duration: 2; --size: 10;">
+            <div class="timer">
               <div class="mask">
               </div>
             </div>
@@ -68,15 +68,12 @@
 </body>
 <footer>
   <script type="text/javascript">
-    document.querySelectorAll('.alert input[type=checkbox]').forEach(function($el) {
+    document.querySelectorAll('.alert input[type=checkbox]').forEach(($el) => {
-      console.log("Setting timeout on", $el);
+      document.querySelectorAll(`.alert label[for=${$el.id}] .timer`).forEach(($it) => {
-      document.querySelectorAll(`.alert label[for=${$el.id}] .paused-timer`).forEach(function($it) {
+        $it.addEventListener("animationend", () => {
-        $it.setAttribute("class", "timer");
+          $el.click();
+        }, {once: true});
       });
-      setTimeout(() => {
-        console.log("Timeout firing...")
-        $el.click();
-      }, 2000);
     });
   </script>
 </footer>

projects/tentacles/src/python/tentacles/templates/printers.html.j2

@@ -6,7 +6,7 @@
     {% if printers %}
     <ul>
       {% for printer in printers %}
-      {% with id, name, url, last_poll, status = printer %}
+      {% with id, name, url, _api_key, last_poll, status = printer %}
       <li class="printer row">
         <span class="printer-name">{{name}}</span>
         <span class="printer-url"><code>{{url}}</code></span>

projects/tentacles/src/python/tentacles/workers.py

@@ -0,0 +1,131 @@
+#!/usr/bin/env python3
+
+"""Corn jobs 🌽
+
+Supporting the core app with asynchronous maintenance tasks.
+
+Mostly related to monitoring and managing Printer state.
+"""
+
+from time import sleep
+from threading import Thread, Event
+from typing import Callable
+from datetime import timedelta, datetime
+import logging
+from contextlib import closing
+from urllib import parse as urlparse
+from tentacles.store import Store
+
+from octorest import OctoRest as _OR
+from requests import Response
+from requests.exceptions import HTTPError, ConnectionError, Timeout
+
+
+class OctoRest(_OR):
+    def _get(self, path, params=None):
+        url = urlparse.urljoin(self.url, path)
+        response = self.session.get(url, params=params, timeout=(0.1, 1.0))
+        self._check_response(response)
+
+        return response.json()
+
+    def _check_response(self, response: Response):
+        response.raise_for_status()
+        return response
+
+
+log = logging.getLogger(__name__)
+
+SHUTDOWN = Event()
+
+
+def corn_job(every: timedelta):
+    def _decorator(f):
+        def _helper(*args, **kwargs):
+            last = None
+            while not SHUTDOWN.is_set():
+                if not last or (datetime.now() - last) > every:
+                    log.debug(f"Ticking job {f.__name__}")
+                    try:
+                        last = datetime.now()
+                        f(*args, **kwargs)
+                    except Exception:
+                        log.exception(f"Error while procesing task {f.__name__}")
+                else:
+                    sleep(1)
+
+        return _helper
+
+    return _decorator
+
+
+@corn_job(timedelta(seconds=5))
+def poll_printers(db_factory: Callable[[], Store]) -> None:
+    """Poll printers for their status."""
+
+    with closing(db_factory()) as db:
+        for printer in db.list_printers():
+            id, name, url, api_key, last_poll, status = printer
+            try:
+                client = OctoRest(url=url, apikey=api_key)
+                job = client.job_info()
+                state = client.printer().get("state").get("flags", {})
+                if state.get("error"):
+                    db.update_printer_status(id, "error")
+                elif state.get("ready"):
+                    db.update_printer_status(id, "idle")
+                elif state.get("printing"):
+                    db.update_printer_status(id, "running")
+                else:
+                    raise Exception(f"Indeterminate state {state!r}")
+
+            except (ConnectionError, Timeout):
+                db.update_printer_status(id, "error")
+
+            except HTTPError as e:
+                assert isinstance(e.response, Response)
+                if e.response.status_code in [403, 401] or "error" in job:
+                    db.update_printer_status(id, "error")
+                elif e.response.json().get("error") == "Printer is not operational":
+                    db.update_printer_status(id, "disconnected")
+                else:
+                    raise Exception(
+                        f"Indeterminate state {e.response.status_code}, {e.response.json()!r}"
+                    )
+
+
+@corn_job(timedelta(seconds=5))
+def assign_jobs(db_factory: Callable[[], Store]) -> None:
+    """Assign jobs to printers. Uploading files and job state management is handled separately."""
+
+    with closing(db_factory()) as db:
+        for printer_id in db.list_idle_printers():
+            printer = db.fetch_printer(printer_id)
+            if printer.status != "idle":
+                continue
+
+            if next_job_id := db.poll_job_queue():
+                db.assign_job(next_job_id, printer_id)
+
+
+@corn_job(timedelta(seconds=5))
+def push_jobs(db_factory: Callable[[], Store]) -> None:
+    """Ensure that job files are uploaded and started to the assigned printer."""
+
+    with closing(db_factory()) as db:
+        for job in db.list_mapped_jobs():
+            printer = db.fetch_printer(job.printer_id)
+            file = db.fetch_file(job.file_id)
+            try:
+                client = OctoRest(printer.url, printer.api_key)
+                client.upload(file.filename, select=True, print=True)
+                db.start_job(job.id)
+            except Exception:
+                log.exception("Oop")
+
+
+def create_workers(db_factory: Callable[[], Store]) -> Event:
+    Thread(target=poll_printers, args=[db_factory]).start()
+    Thread(target=assign_jobs, args=[db_factory]).start()
+    Thread(target=push_jobs, args=[db_factory]).start()
+    return SHUTDOWN