Log.io - Real-time log monitoring in your browser
Powered by node.js + socket.io
How does it work?
A file input watches log files for changes, sends new messages to the server via TCP, which broadcasts to browsers via socket.io.
Users can watch adhoc log streams by activating inputs and binding them to multiple screens via the web UI.
Terminology
Stream - A logical designation for a group of messages that relate to one another. Examples include an application name, a topic name, or a backend service name.
Source - A physical designation for a group of messages that originate from the same source. Examples include a server name, a service provider name, or a filename.
Input - A (stream, source) pair.
While originally designed to represent backend service logs spread across multiple servers, the stream/source abstraction is intentionally open-ended to allow users to define a system topology for their specific use case.
Install & run server
Install via npm
npm install -g log.io
Configure hosts & ports (see example below)
nano ~/.log.io/server.json
Run server
log.io-server
Browse to http://localhost:6688
Install & run file input
Install via npm
npm install -g log.io-file-input
Configure file input (see example below)
nano ~/.log.io/inputs/file.json
Run file input
log.io-file-input
Server configuration
There are two servers: the message server, which receives TCP messages from message inputs, and the HTTP server, which receives requests from browsers. By default, the application looks for configuration in ~/.log.io/server.json, and can be overridden with the environment variable LOGIO_SERVER_CONFIG_PATH.
Sample configuration file:
{
"messageServer": {
"port": 6689,
"host": "127.0.0.1"
},
"httpServer": {
"port": 6688,
"host": "127.0.0.1"
},
"debug": false
}
File input configuration
Inputs are created by associating file paths with stream and source names in a configuration file. By default, the file input looks for configuration in ~/.log.io/inputs/file.json, and can be overridden with the environment variable LOGIO_FILE_INPUT_CONFIG_PATH.
Sample configuration file:
{
"messageServer": {
"host": "127.0.0.1",
"port": 6689
},
"inputs": [
{
"source": "server1",
"stream": "app1",
"config": {
"path": "log.io-demo/file-generator/app1-server1.log"
}
},
{
"source": "server2",
"stream": "app1",
"config": {
"path": "log.io-demo/file-generator/app1-server2.log"
}
},
{
"source": "server1",
"stream": "app2",
"config": {
"path": "log.io-demo/file-generator/app2-server1.log"
}
},
{
"source": "server2",
"stream": "app2",
"config": {
"path": "log.io-demo/file-generator/app2-server2.log"
}
}
]
}
Server TCP interface
The file input connects to the server via TCP, and writes properly formatted strings to the socket. Custom inputs can send messages to the server using the following commands, each of which ends with a null character:
Send a log message
+msg, streamName1, sourceName1, this is log message\0
Register a new input
+input, streamName1, sourceName1\0
Remove an existing input
-input, streamName1, sourceName1\0