# LokiLogger
LokiLogger is an Elixir logger backend providing support for Logging to [Grafana Loki](https://github.com/grafana/loki)
[](https://hex.pm/packages/loki_logger)
## Known issues
* "works-on-my-machine" level of quality. Love to get your feedback in the repo's Github issues
## TODO
* async http call to backend.
* snappy compressed proto format in the HTTP Body instead of JSON.
* proper unit tests.
* http post retry strategy on temporary loki backend failure or network hiccups.
* authentication with basic auth and/or Oauth2 reverse proxy.
* support for tenant header (X-Scope-OrgID) in multi-tenancy scenario's.
* CI build integration (e.g. TravisCI)
## Installation
The package can be installed by adding `loki_logger` to your list of dependencies in `mix.exs`:
```elixir
def deps do
[
{:loki_logger, "~> 0.1.0"}
]
end
```
## Configuration
### Elixir Project
Loki Logger's behavior is controlled using the application configuration environment:
* __loki_host__ : the hostname of the syslog server e.g. http://localhost:3100
* __loki_labels__ : the Loki log labels used to select the log stream in e.g. Grafana
* __level__: logging threshold. Messages "above" this threshold will be discarded. The supported levels, ordered by precedence are :debug, :info, :warn, :error.
* __format__: the format message used to print logs. Defaults to: "$metadata level=$level $levelpad$message". It may also be a {module, function} tuple that is invoked with the log level, the message, the current timestamp and the metadata.
* __metadata__: the metadata to be printed by $metadata. Defaults to to :all, which prints all metadata.
* __max_buffer__: the amount of entries to buffer before posting to the Loki REST api. Defaults to 32.
For example, the following `config/config.exs` file sets up Loki Logger using
level debug, with `application` label `loki_logger_library`.
```elixir
use Mix.Config
config :logger,
backends: [LokiLogger]
config :logger, :loki_logger,
level: :debug,
format: "$metadata level=$level $levelpad$message",
metadata: :all,
max_buffer: 300,
loki_labels: %{application: "loki_logger_library", elixir_node: node()},
loki_host: "http://localhost:3100"
```
## License
Loki Logger is copyright (c) 2019 Ward Bekker
The source code is released under the Apache v2.0 License.
Check [LICENSE](LICENSE) for more information.
