Merge pull request #41 from satyaog/feature/logs

Add systemd journal viewer

paperoni/webapp/admin/logs.py

@@ -0,0 +1,17 @@
+from starbear import bear
+
+from ..common import LogsViewer, config, mila_template
+
+
+@bear
+@mila_template(help="/help#logs")
+async def app(page, box):
+ """Monitor systemd logs."""
+ try:
+ services = config().services
+ except AttributeError:
+ services = []
+ await LogsViewer(services).run(box)
+
+
+ROUTES = app

paperoni/webapp/app-style.css

@@ -191,6 +191,13 @@ input[type="text"], input[type="date"] {
  background: lightsalmon;
 }
 
+.validation-button input[type="radio"][class="log-button"] {
+ height: 3.5em;
+}
+.validation-button input[type="radio"][class="log-button"]:checked {
+ background: lightgreen;
+}
+
 /* Papers */
 
 .paper {
@@ -446,3 +453,9 @@ form.update-file textarea {
  width: 100%;
  height: 500px;
 }
+
+div.log-stream textarea {
+ display: block;
+ width: 100%;
+ height: 500px;
+}

paperoni/webapp/common.py

@@ -1,5 +1,7 @@
 import asyncio
+import html
 import os
+import subprocess
 import traceback
 from functools import wraps
 from pathlib import Path
@@ -74,6 +76,78 @@ async def run(self, page):
  page[actionarea].set(H.button("Update", name="update"))
 
 
+class LogsViewer:
+ def __init__(self, services):
+ self.services = services
+
+ async def run(self, page):
+ q = Queue()
+ debounced = ClientWrap(q, debounce=0.3, form=True)
+ active_service = next(iter(self.services), None)
+
+ page.print(
+ H.form["logs-radio"](
+ *(
+ H.label["validation-button"](
+ H.input(
+ type="radio",
+ name=f"v-logs-radio",
+ value=s,
+ checked=active_service == s,
+ onchange=debounced,
+ **{"class":"log-button"},
+ ),
+ s,
+ )
+ for s in self.services
+ )
+ )
+ )
+
+ page.print(
+ H.div["log-stream"](
+ log_stream := H.textarea(
+ "".join(
+ self.__class__.journal(active_service, 10000)
+ if active_service else []
+ ),
+ name="log-stream",
+ readonly=True,
+ ).autoid(),
+ ),
+ )
+ page[log_stream].do("this.scrollTop = this.scrollTopMax")
+
+ async for event in q:
+ for k, v in event.items():
+ if k.startswith("v-"):
+ page[log_stream].clear()
+ blocks = []
+ for i, l in enumerate(self.__class__.journal(v, 10000)):
+ blocks.append(html.escape(l))
+ if i % 2000 == 0:
+ page[log_stream].print_html("".join(blocks))
+ page[log_stream].do("this.scrollTop = this.scrollTopMax")
+ blocks = ["\n"]
+ if blocks[1:]:
+ page[log_stream].print_html("".join(blocks))
+ page[log_stream].do("this.scrollTop = this.scrollTopMax")
+
+
+ @staticmethod
+ def journal(service, tail=-1):
+ with subprocess.Popen([
+ "journalctl",
+ *(("-n", str(tail)) if tail > 0 else tuple()),
+ "-qu", service,
+ # TODO: make viewer follow the journal logs
+ # "--follow",
+ # "--no-tail",
+ ], stdout=subprocess.PIPE, stderr=subprocess.STDOUT) as process:
+ for l in process.stdout:
+ yield l.decode("utf-8")
+
+
 class GUI:
  def __init__(self, page, db, queue, params, defaults):
  self.page = page