Add new tutorial to send docker logs into Quickwit. (#4013)

* Add new tutorial to send docker logs into Quickwit.

* Add screenshot in docker logs tutorial.

docs/log-management/send-logs/send-docker-logs.md

@@ -0,0 +1,147 @@
+---
+title: Send docker logs into Quickwit
+sidebar_label: Docker logs into Quickwit
+description: Send docker logs into Quickwit
+tags: [otel, docker, collector, log]
+sidebar_position: 5
+---
+
+To send docker container logs into Quickwit, you just need to setup an OpenTelemetry Collector with the file logs receiver. In this tutorial, we will use `docker compose` to start the collector and Quickwit.
+
+You only needs a minute to get you Quickwit log UI!
+
+![Quickwit UI Logs](../../assets/images/screenshot-quickwit-ui-docker-compose-logs.png)
+
+## OTEL collector configuration
+
+The following collector configuration will collect docker logs in `/var/lib/docker/containers/*/*-json.log` (depending on your system, log files can be at a different location), add a few attributes and send them to Quickwit through gRPC at `http://quickwit:7281`.
+
+
+```yaml title="otel-collector-config.yaml"
+receivers:
+  filelog:
+    include:
+      - /var/lib/docker/containers/*/*-json.log
+    operators:
+     - id: parser-docker
+       timestamp:
+         layout: '%Y-%m-%dT%H:%M:%S.%LZ'
+         parse_from: attributes.time
+       type: json_parser
+     - field: attributes.time
+       type: remove
+     - id: extract_metadata_from_docker_tag
+       parse_from: attributes.attrs.tag
+       regex: ^(?P<name>[^\|]+)\|(?P<image_name>[^\|]+)\|(?P<id>[^$]+)$
+       type: regex_parser
+       if: 'attributes?.attrs?.tag != nil'
+     - from: attributes.name
+       to: resource["docker.container.name"]
+       type: move
+       if: 'attributes?.name != nil'
+     - from: attributes.image_name
+       to: resource["docker.image.name"]
+       type: move
+       if: 'attributes?.image_name != nil'
+     - from: attributes.id
+       to: resource["docker.container.id"]
+       type: move
+       if: 'attributes?.id != nil'
+     - from: attributes.log
+       to: body
+       type: move
+
+processors:
+  batch:
+    timeout: 5s
+
+exporters:
+  otlp/qw:
+    endpoint: quickwit:7281
+    compression: none
+    tls:
+      insecure: true
+
+service:
+  pipelines:
+    logs:
+      receivers: [filelog]
+      processors: [batch]
+      exporters: [otlp/qw]
+```
+
+## Start the OTEL collector and a Quickwit instance
+
+Let's use `docker compose` with the following configuration:
+
+```yaml title="docker-compose.yaml"
+version: "3"
+
+x-default-logging: &logging
+ driver: "json-file"
+ options:
+   max-size: "5m"
+   max-file: "2"
+   tag: "{{.Name}}|{{.ImageName}}|{{.ID}}"
+
+services:
+  quickwit:
+    image: quickwit/quickwit:${QW_VERSION:-0.6.5}
+    volumes:
+      - ./qwdata:/quickwit/qwdata
+    ports:
+      - 7280:7280
+    environment:
+      - NO_COLOR=true
+    command: ["run"]
+    logging: *logging
+
+  otel-collector:
+    user: "0" # Needed to access the directory /var/lib/docker/containers/
+    image: otel/opentelemetry-collector-contrib:${OTEL_VERSION:-0.87.0}
+    volumes:
+      - ./otel-collector-config.yaml:/etc/otel-collector-config.yaml
+      - /var/lib/docker/containers:/var/lib/docker/containers:ro
+    command: ["--config=/etc/otel-collector-config.yaml"] 
+    logging: *logging
+```
+
+
+You will notice the custom `logging`, the OTEL collector will use that additional information to enrich the logs.
+
+## Run it and search
+
+Download the configuration files and start the containers:
+
+```bash
+
+mkdir qwdata
+docker compose up
+```
+
+After a few seconds, you will see the logs in the Quickwit UI [http://localhost:7280](http://localhost:7280).
+
+
+Here is what it should look like:
+
+```json
+{
+  "attributes": {
+    "log.file.name": "34ad1a84c71de1d29ad75f99b56d01205e2976440f2398734037151ba2bcde1a-json.log",
+    "stream": "stdout"
+  },
+  "body": {
+    "message": "2023-10-23T16:39:57.892  INFO --- [   asgi_gw_1] localstack.request.aws     : AWS s3.ListObjects => 200\n"
+  },
+  "observed_timestamp_nanos": 1698079197979435000,
+  "service_name": "unknown_service",
+  "severity_number": 0,
+  "timestamp_nanos": 1698079197892726000,
+  "trace_flags": 0
+}
+```
+
+
+## Troubleshooting
+
+It's possible that you get no logs in the UI. In this case, check the `docker compose` logs. The problem can typically come from a wrong configuration of the OTEL collector.