jaslog 0.1.4

A colored log reader for JSON logs
Documentation 
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# Jaslog

![Rust](https://github.com/jbruggem/jaslog/workflows/Rust/badge.svg)

A log reader for structured logs that handles non-json lines, displays beautifully
colored logs and can filter based on the fields of the json.

![](doc/screenshot1.png)

![](doc/screenshot2.png)

- non-json lines will be displayed but marked clearly
- filters work for any fields, even fields that are not recognized
- if the structure of the JSON is not recognized, all the field will be shown on the log line
- there is no way to control which fields are displayed
- there is no way to control the formatting

It will work especially well with certain specific JSON structures (see "Supported formats").

## Install

1. Download the binary from the [latest release](https://github.com/jbruggem/jaslog/releases)
2. Put it in the folder that's part of your PATH
3. Make it executable (`chmod +x`)

## Usage

Basic usage:

```sh
$ jaslog file.json.log
```

Or using stdin:

```sh
$ cat file.json.log | jaslog
```

You can filter. Syntax is:

* `<field>=<value>`: search for exact value of field
* `<field>=+<value>`: search for value in field (suggestions of a better syntax are welcome :-P)
* `<field>=^<value>`: search for **absence** of value in field (suggestions of a better syntax are welcome :-P)

```sh
$ jaslog -f level=info file.json.log
```

You can also can also ask to read only the first n lines:


```sh
$ jaslog -f level=info -n 50 file.json.log
```

## Explicitly supported formats

Pull requests to support new formats are welcome of course !

Elixir logs:

```json
{
    "app": "ecto_sql",
    "level": "info",
    "message": "create index etc...",
    "metadata": {},
    "module": "Elixir.Ecto.Migration.Runner",
    "pid": "#PID<0.280.0>",
    "timestamp": "2019-12-18T10:55:50.000393"
}
```

Logstash's jsonevent-layout logs:

```json
{
    "@timestamp": "2020-01-13T12:34:01.740Z",
    "source_host": "04fc4fd30dc3",
    "file": "Dispatcher.java",
    "method": "tryAcceptLeadershipAndRunJobs",
    "level": "DEBUG",
    "line_number": "927",
    "thread_name": "flink-akka.actor.default-dispatcher-3",
    "@version": 1,
    "logger_name": "org.apache.flink.runtime.dispatcher.StandaloneDispatcher",
    "message": "Dispatcher akka.tcp://flink@04fc4fd30dc3:6123/user/dispatcher accepted leadership with fencing token 00000000000000000000000000000000. Start recovered jobs.",
    "class": "org.apache.flink.runtime.dispatcher.Dispatcher",
    "mdc": {}
    }
```

### Releasing

* Update version in Cargo.toml
* Commit
* tag with `v<version>`, then push