Plugin Overview

OctoPrint Log Monitor streams OctoPrint logs live, searches them with pagination and severity filters, and shows alert badges in the navbar and sidebar.

Core features

• Live log streaming (single file from the UI, multiple files via the API)
• Full-text search with severity filters, regex and case-sensitive modes
• Background severity alerting with history, independent of the UI stream
• Log download and search-result export (CSV/TXT)
• Path traversal protection, rate limiting, and optional masking of sensitive log content

How it works

The backend consists of four small modules:

Module	Responsibility
log_parser	Single source of truth for parsing OctoPrint, serial, and compact log-line formats.
log_tailer	tail -f-style background thread per streamed file; detects rotation and truncation.
log_searcher	Streams through files line by line for search, stats, and exports — memory use is bounded by page size.
security	Filename/path validation, file-size guard, rate limiting, sensitive-data masking.

The plugin core (octoprint_logmonitor/__init__.py) wires these together:

• Live stream — a tailer per streamed file pushes parsed lines into a shared buffer, which is flushed to the browser as one batched WebSocket message per poll interval.
• Alert monitor — separate tailers watch the configured log files and raise severity_alert messages whenever a line matches the trigger levels, even while the Log Monitor tab is closed.
• REST API — all routes live under /plugin/logmonitor; see the REST API reference.

Further reading

• Configuration reference
• REST API reference
• Troubleshooting
• Python API

See the project README for installation notes.