Tailor

Tailor acts as a drop-in replacement for the official Microsoft IIS Service Monitor application with the additional ability to forward the contents of multiple log files (such as the ones created by IIS) to stdout, so they can be seen with docker logs and more easily collected with log aggregation systems.

It will monitor a given Windows service and exit when that service's state changes from SERVICE_RUNNING. In the background, it will collect the contents of any designated log files and write them to stdout in a structured JSON format. You might say it "stitches" together logfiles, hence the name :)

Usage

For simple entrypoint usage, run like you'd run ServiceMonitor:

$ Tailor.exe w3svc

To automatically forward the contents of a log file to stdout, provide the path to the logfile relative to the current working directory:

$ Tailor.exe w3svc /app/logs/log.txt

For convenience, you can provide a glob-style path to tail multiple log files like so:

$ ServiceMonitor.exe w3svc c:\inetpub\logs\LogFiles\*\*.log

Output uses a structured JSON format including a timestamp and source:

...
{"level":"debug","msg":"2018-06-01 20:33:56 ::1 GET /ExampleWebApplication - 80 - ::1 Mozilla/5.0+(Windows+NT+10.0;+Win64;+x64;+rv:60.0)+Gecko/20100101+Firefox/60.0 - 500 0 0 1\r","source":"c:\\inetpub\\logs\\LogFiles\\W3SVC1\\u_ex180601.log","time":"2018-06-01T14:34:21-06:00"}