使用express.logger但写压缩后的日志

Question

I'm trying to figure out how to make the express.logger function write its logs to a gzipped file, instead of uncompressed text. I tried the following code:

var logarchive = zlib.createGzip();
var logfile = fs.createWriteStream('./logs/access.log.gz');
logarchive.pipe(logfile);

app.use(express.logger({
  format: env.get("logformat", "short"),
  stream: logarchive
}));

but that seems to just set up an illegal gzip archive reporting 184Mb of data in it, despite it only getting a few bytes sent during a logging operation.

What's the correct way to hook up these things? The Nodejs.org api documentation on zlib and streams doesn't give any concrete examples on how to achieve getting data sent through zlib to another write stream, and the logger only takes streams as targets.

Answer 1

I think your code should work, but zlib is quite good at buffering data so it might take some time before the logs are flushed to file.

You can periodically flush manually:

setInterval(function() {
  logarchive.flush();
}, 1000); // flush once per second