# LoggerJSON
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[](https://coveralls.io/github/Nebo15/logger_json?branch=master)
[](https://hex.pm/packages/logger_json)
[](https://hexdocs.pm/logger_json/)
[](https://hex.pm/packages/logger_json)
[](https://github.com/Nebo15/logger_json/blob/master/LICENSE.md)
A collection of formatters and utilities for JSON-based logging for various cloud tools and platforms.
## Supported formatters
- [`LoggerJSON.Formatters.Basic`](https://hexdocs.pm/logger_json/LoggerJSON.Formatters.Basic.html) - a basic JSON formatter that logs messages in a structured, but generic format, can be used with any JSON-based logging system.
- [`LoggerJSON.Formatters.GoogleCloud`](https://hexdocs.pm/logger_json/LoggerJSON.Formatters.GoogleCloud.html) - a formatter that logs messages in a structured format that can be consumed by Google Cloud Logger and Google Cloud Error Reporter.
- [`LoggerJSON.Formatters.Datadog`](https://hexdocs.pm/logger_json/LoggerJSON.Formatters.Datadog.html) - a formatter that logs messages in a structured format that can be consumed by Datadog.
- [`LoggerJSON.Formatters.Elastic`](https://hexdocs.pm/logger_json/LoggerJSON.Formatters.Elastic.html) - a formatter that logs messages in a structured format that conforms to the [Elastic Common Schema (ECS)](https://www.elastic.co/guide/en/ecs/8.11/ecs-reference.html), so it can be consumed by ElasticSearch, LogStash, FileBeat and Kibana.
## Installation
Add `logger_json` to your list of dependencies in `mix.exs`:
```elixir
def deps do
[
# ...
{:logger_json, "~> 6.0"}
# ...
]
end
```
and install it running `mix deps.get`.
Then, enable the formatter in your `config.exs`:
```elixir
config :logger, :default_handler,
formatter: {LoggerJSON.Formatters.Basic, []}
```
or during runtime (eg. in your `application.ex`):
```elixir
:logger.update_handler_config(:default, :formatter, {Basic, []})
```
You might also want to format the log messages when migrations are running:
```elixir
config :domain, MyApp.Repo,
# ...
start_apps_before_migration: [:logger_json]
```
Additionally, you may also be try [redirecting otp reports to Logger](https://hexdocs.pm/logger/Logger.html#module-configuration) (see "Configuration" section).
## Configuration
Configuration can be set using 2nd element of the tuple of the `:formatter` option in `Logger` configuration.
For example in `config.exs`:
```elixir
config :logger, :default_handler,
formatter: {LoggerJSON.Formatters.GoogleCloud, metadata: :all, project_id: "logger-101"}
```
or during runtime:
```elixir
:logger.update_handler_config(:default, :formatter, {Basic, metadata: {:all_except, [:conn]}})
```
## Docs
The docs can be found at [https://hexdocs.pm/logger_json](https://hexdocs.pm/logger_json).
## Examples
### Basic
```json
{
"message": "Hello",
"metadata": {
"domain": ["elixir"]
},
"severity": "notice",
"time": "2024-04-11T21:31:01.403Z"
}
```
### Google Cloud Logger
Follows the [Google Cloud Logger LogEntry](https://cloud.google.com/logging/docs/reference/v2/rest/v2/LogEntry) format,
for more details see [special fields in structured payloads](https://cloud.google.com/logging/docs/agent/configuration#special_fields_in_structured_payloads).
```json
{
"logging.googleapis.com/trace": "projects/my-projectid/traces/0679686673a",
"logging.googleapis.com/spanId": "000000000000004a",
"logging.googleapis.com/operation": {
"pid": "#PID<0.29081.0>"
},
"logging.googleapis.com/sourceLocation": {
"file": "/Users/andrew/Projects/os/logger_json/test/formatters/google_cloud_test.exs",
"function": "Elixir.LoggerJSON.Formatters.GoogleCloudTest.test logs an LogEntry of a given level/1",
"line": 44
},
"message": {
"domain": ["elixir"],
"message": "Hello"
},
"severity": "NOTICE",
"time": "2024-04-12T15:07:55.020Z"
}
```
and this is how it looks in Google Cloud Logger:
```json
{
"insertId": "1d4hmnafsj7vy1",
"jsonPayload": {
"message": "Hello",
"logging.googleapis.com/spanId": "000000000000004a",
"domain": ["elixir"],
"time": "2024-04-12T15:07:55.020Z"
},
"resource": {
"type": "gce_instance",
"labels": {
"zone": "us-east1-d",
"project_id": "firezone-staging",
"instance_id": "3168853301020468373"
}
},
"timestamp": "2024-04-12T15:07:55.023307594Z",
"severity": "NOTICE",
"logName": "projects/firezone-staging/logs/cos_containers",
"operation": {
"id": "F8WQ1FsdFAm5ZY0AC1PB",
"producer": "#PID<0.29081.0>"
},
"trace": "projects/firezone-staging/traces/bc007e40a2e9edffa23785d8badc43b8",
"sourceLocation": {
"file": "lib/phoenix/logger.ex",
"line": "231",
"function": "Elixir.Phoenix.Logger.phoenix_endpoint_stop/4"
},
"receiveTimestamp": "2024-04-12T15:07:55.678986520Z"
}
```
Exception that can be sent to Google Cloud Error Reporter:
```json
{
"httpRequest": {
"protocol": "HTTP/1.1",
"referer": "http://www.example.com/",
"remoteIp": "",
"requestMethod": "PATCH",
"requestUrl": "http://www.example.com/",
"status": 503,
"userAgent": "Mozilla/5.0"
},
"logging.googleapis.com/operation": {
"pid": "#PID<0.250.0>"
},
"logging.googleapis.com/sourceLocation": {
"file": "/Users/andrew/Projects/os/logger_json/test/formatters/google_cloud_test.exs",
"function": "Elixir.LoggerJSON.Formatters.GoogleCloudTest.test logs exception http context/1",
"line": 301
},
"@type": "type.googleapis.com/google.devtools.clouderrorreporting.v1beta1.ReportedErrorEvent",
"context": {
"httpRequest": {
"protocol": "HTTP/1.1",
"referer": "http://www.example.com/",
"remoteIp": "",
"requestMethod": "PATCH",
"requestUrl": "http://www.example.com/",
"status": 503,
"userAgent": "Mozilla/5.0"
},
"reportLocation": {
"filePath": "/Users/andrew/Projects/os/logger_json/test/formatters/google_cloud_test.exs",
"functionName": "Elixir.LoggerJSON.Formatters.GoogleCloudTest.test logs exception http context/1",
"lineNumber": 301
}
},
"domain": ["elixir"],
"message": "Hello",
"serviceContext": {
"service": "nonode@nohost"
},
"stack_trace": "** (EXIT from #PID<0.250.0>) :foo",
"severity": "DEBUG",
"time": "2024-04-11T21:34:53.503Z"
}
```
## Datadog
Adheres to the [default standard attribute list](https://docs.datadoghq.com/logs/processing/attributes_naming_convention/#default-standard-attribute-list)
as much as possible.
```json
{
"domain": ["elixir"],
"http": {
"method": "GET",
"referer": "http://www.example2.com/",
"request_id": null,
"status_code": 200,
"url": "http://www.example.com/",
"url_details": {
"host": "www.example.com",
"path": "/",
"port": 80,
"queryString": "",
"scheme": "http"
},
"useragent": "Mozilla/5.0"
},
"logger": {
"file_name": "/Users/andrew/Projects/os/logger_json/test/formatters/datadog_test.exs",
"line": 239,
"method_name": "Elixir.LoggerJSON.Formatters.DatadogTest.test logs http context/1",
"thread_name": "#PID<0.225.0>"
},
"message": "Hello",
"network": {
"client": {
"ip": "127.0.0.1"
}
},
"syslog": {
"hostname": "MacBook-Pro",
"severity": "debug",
"timestamp": "2024-04-11T23:10:47.967Z"
}
}
```
## Elastic
Follows the [Elastic Common Schema (ECS)](https://www.elastic.co/guide/en/ecs/8.11/ecs-reference.html) format.
```json
{
"@timestamp": "2024-05-21T15:17:35.374Z",
"ecs.version": "8.11.0",
"log.level": "info",
"log.logger": "Elixir.LoggerJSON.Formatters.ElasticTest",
"log.origin": {
"file.line": 18,
"file.name": "/app/logger_json/test/logger_json/formatters/elastic_test.exs",
"function": "test logs message of every level/1"
},
"message": "Hello"
}
```
When an error is thrown, the message field is populated with the error message and the `error.` fields will be set:
> Note: when throwing a custom exception type that defines the fields `id` and/or `code`, then the `error.id` and/or `error.code` fields will be set respectively.
```json
{
"@timestamp": "2024-05-21T15:20:11.623Z",
"ecs.version": "8.11.0",
"error.message": "runtime error",
"error.stack_trace": "** (RuntimeError) runtime error\n test/logger_json/formatters/elastic_test.exs:191: anonymous fn/0 in LoggerJSON.Formatters.ElasticTest.\"test logs exceptions\"/1\n",
"error.type": "Elixir.RuntimeError",
"log.level": "error",
"message": "runtime error"
}
```
Any custom metadata fields will be added to the root of the message, so that your application can fill any other ECS fields that you require:
> Note that this also allows you to produce messages that do not strictly adhere to the ECS specification.
```json
// Logger.info("Hello") with Logger.metadata(:"device.model.name": "My Awesome Device")
// or Logger.info("Hello", "device.model.name": "My Awesome Device")
{
"@timestamp": "2024-05-21T15:17:35.374Z",
"ecs.version": "8.11.0",
"log.level": "info",
"log.logger": "Elixir.LoggerJSON.Formatters.ElasticTest",
"log.origin": {
"file.line": 18,
"file.name": "/app/logger_json/test/logger_json/formatters/elastic_test.exs",
"function": "test logs message of every level/1"
},
"message": "Hello",
"device.model.name": "My Awesome Device"
}
```
## Copyright and License
Copyright (c) 2016 Andrew Dryga
Released under the MIT License, which can be found in [LICENSE.md](./LICENSE.md).
