tcp-log-server

11.0.3 • Public • Published

Serve an append-only log over TCP.

  • Uses a dead-simple, JSON-based protocol.
  • Stores entries as content-addressed blobs.
  • Persists to disk by default.
npm install --global tcp-log-server
tcp-log-server

Logs

The server uses pino logging. To improve console log output:

npm install --global pino
tcp-log-server | tee server.log | pino

Environment

Configure tcp-log-server with environment variables:

  • PORT for TCP
  • BLOBS directory for entry JSON files, named by hash, or memory to store in memory
  • FILE for the list of entries

Node.js

The package exports a factory function. Given a pino log, a file path, an abstract-blob-store, and an EventEmitter, it returns a TCP connection handler function suitable for net.createServer(handler). You may also provide a hash function and hash length.

Protocol

The server accepts TCP connections. It enables keep-alive on each socket. All messages are newline-delimited JSON objects. tcp-log-client provides a high-level interface.

Clients can send:

Read

{"from":1,"read":5}

On receipt, the server will begin sending up to read log entries with indices greater than or equal to from, in ascending-index order. (The lowest possible index is 1.)

Each entry will be sent like:

{"index":"1","entry":{"some":"entry"}}

Servers may report errors reading specific log entries:

{"index":45,"error":"some-error"}

If the server reaches the head of its log before sending read entries, it will send:

{"current":true}

Once the server has sent read entries, it will report the index of the head of its log:

{"head":100}

Write

{"id":"some-id","entry":{"arbitrary":"data"}}

require('uuid').v4(), with the uuid package, is an easy way to generate id strings.

Once successfully appended to the log, the server will confirm the index of the newly appended entry.

{"id":"some-id","index":44}

If there is an error, the server will instead respond:

{"id":"some-id-string","error":"error-string"}

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Install

npm i tcp-log-server

Weekly Downloads

2

Version

11.0.3

License

BlueOak-1.0.0

Unpacked Size

17.2 kB

Total Files

5

Last publish

Collaborators

  • kemitchell