[ AGNTLOG-444 ] Add devcontainer configuration

.devcontainer/Dockerfile

@@ -0,0 +1,12 @@
+FROM fluent/fluentd:latest
+
+ENV DEBIAN_FRONTEND=noninteractive
+USER root
+
+RUN apt-get update && apt-get install -y \
+    build-essential \
+    git \
+    curl
+
+WORKDIR /workspaces
+

.devcontainer/devcontainer.json

@@ -0,0 +1,21 @@
+// .devcontainer/devcontainer.json
+{
+  "name": "Fluent Plugin Datadog Dev",
+  "build": {
+    "dockerfile": "Dockerfile"
+  },
+  "workspaceFolder": "/workspaces/fluent-plugin-datadog",
+  "postCreateCommand": "bundle install --jobs 4 --retry 3",
+  "customizations": {
+    "vscode": {
+      "extensions": [
+        "shopify.ruby-lsp",
+        "ms-azuretools.vscode-docker"
+      ],
+      "settings": {  
+        "rubyLsp.bundleExec": true,
+        "rubyLsp.useBundler": true
+      }
+    }
+  }
+}

.vscode/launch.json

@@ -0,0 +1,11 @@
+{
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "type": "ruby_lsp",
+            "request": "launch",
+            "name": "Run Tests",
+            "program": "bundle exec ruby -Itest test/plugin/test_out_datadog.rb",
+        }
+    ]
+} 

README.md

@@ -156,3 +156,11 @@ To build a new version of this plugin and push it to RubyGems:
 
 `curl -u <USERNAME> https://rubygems.org/api/v1/api_key.yaml > ~/.gem/credentials`, it will ask for your password.
 
+## Development Environment
+
+This repository includes the files to run it in a dev container in VS Code. To use it:
+
+1. Install VS Code and Docker.
+2. Open the project in VS Code with the Dev Containers extension.
+
+VS Code will build and start the container automatically.

fluent-plugin-datadog.gemspec

@@ -28,8 +28,9 @@ Gem::Specification.new do |spec|
 
   spec.add_development_dependency "bundler", "~> 2.1"
   spec.add_development_dependency "test-unit", '~> 3.1'
-  spec.add_development_dependency "rake", "~> 12.0"
   spec.add_development_dependency 'webmock', "~> 3.6.0"
+  spec.add_development_dependency "ruby-debug-ide"
+  spec.add_development_dependency "rake", "~> 12.0"
 
   spec.metadata      = {
     'bug_tracker_uri'   => 'https://github.com/DataDog/fluent-plugin-datadog/issues',

test/TestApp/README.md

@@ -0,0 +1,47 @@
+# TestApp - Typical Fluentd Usage Example
+
+This directory demonstrates an example of fluentd usage with the Datadog plugin - using configuration files and running Fluentd as a service.
+
+## Files
+
+- **`fluent.conf`** - Fluentd configuration file
+- **`start_fluentd.sh`** - Script to start Fluentd with the configuration
+- **`send_test_logs.sh`** - Script to send test logs via HTTP (bash)
+
+## Quick Start
+
+### 1. Set your Datadog API Key
+
+```bash
+export DD_API_KEY=your_api_key_here
+```
+
+### 2. Start Fluentd
+
+```bash
+./start_fluentd.sh
+```
+
+This starts Fluentd as a service with the configuration file. Fluentd will:
+- Listen on HTTP port 8888 for log ingestion
+- Listen on Forward port 24224 for Fluentd protocol
+- Route logs matching `test.**` to Datadog
+
+### 3. Send Test Logs
+
+In another terminal:
+
+```bash
+# Using bash script
+./send_test_logs.sh
+
+# Or manually with curl
+curl -X POST -d 'json={"message":"Hello from Fluentd"}' \
+  http://localhost:8888/test.app
+```
+
+### 4. Verify Logs
+
+Check your Datadog dashboard to see the logs appear. They should include:
+- Original log fields
+- Datadog metadata: `ddsource`, `ddtags`, `service`, `hostname`, `tag`, `@timestamp`

test/TestApp/fluent.conf

@@ -0,0 +1,38 @@
+# Typical Fluentd configuration file for Datadog plugin
+# This is how Fluentd is typically configured in production
+
+# HTTP input - allows sending logs via HTTP POST
+<source>
+  @type http
+  port 8888
+  bind 0.0.0.0
+</source>
+
+# Forward input - allows sending logs via Fluentd forward protocol
+<source>
+  @type forward
+  port 24224
+  bind 0.0.0.0
+</source>
+
+# Match events and send them to Datadog
+<match test.**>
+  @type datadog
+  @id datadog_output
+  api_key YOUR_API_KEY_HERE
+
+  # Optional configuration
+  include_tag_key true
+  tag_key 'tag'
+  service 'fluentd-test-app'
+  dd_source 'ruby'
+  dd_tags 'env:test,app:testapp'
+
+  <buffer>
+    @type memory
+    flush_interval 3s
+    chunk_limit_size 5m
+    chunk_limit_records 500
+  </buffer>
+</match>
+

test/TestApp/send_test_logs.sh

@@ -0,0 +1,41 @@
+#!/bin/bash
+# Unless explicitly stated otherwise all files in this repository are licensed
+# under the Apache License Version 2.0.
+# This product includes software developed at Datadog (https://www.datadoghq.com/).
+# Copyright 2018 Datadog, Inc.
+
+# Script to send test logs to Fluentd via HTTP
+# This demonstrates typical usage - sending logs to Fluentd's HTTP endpoint
+
+FLUENTD_URL="${FLUENTD_URL:-http://localhost:8888}"
+TAG="${TAG:-test.app}"
+
+echo "Sending test logs to Fluentd at ${FLUENTD_URL}"
+echo "Tag: ${TAG}"
+echo ""
+
+# Send test log 1
+echo "Sending log 1: Test message"
+curl -X POST -d 'json={"message":"Test log message from TestApp","level":"info","user":"test_user","action":"test_action"}' \
+  "${FLUENTD_URL}/${TAG}"
+
+echo ""
+echo ""
+
+# Send test log 2
+echo "Sending log 2: Debug message"
+curl -X POST -d 'json={"message":"Another test message","level":"debug","component":"test_component","status":"success"}' \
+  "${FLUENTD_URL}/${TAG}"
+
+echo ""
+echo ""
+
+# Send test log 3
+echo "Sending log 3: Error simulation"
+curl -X POST -d 'json={"message":"Error simulation","level":"error","error_code":"TEST_ERROR","stack_trace":"test_stack_trace"}' \
+  "${FLUENTD_URL}/${TAG}"
+
+echo ""
+echo ""
+echo "Check Fluentd output or Datadog dashboard to verify logs were received."
+

test/TestApp/start_fluentd.sh

@@ -0,0 +1,50 @@
+#!/bin/bash
+# Unless explicitly stated otherwise all files in this repository are licensed
+# under the Apache License Version 2.0.
+# This product includes software developed at Datadog (https://www.datadoghq.com/).
+# Copyright 2018 Datadog, Inc.
+
+# Script to start Fluentd with the Datadog plugin configuration
+# This demonstrates typical Fluentd usage - running as a service with a config file
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+CONFIG_FILE="${SCRIPT_DIR}/fluent.conf"
+
+# Check if API key is set
+if [ -z "$DD_API_KEY" ]; then
+  echo "Warning: DD_API_KEY environment variable is not set."
+  echo "Please set it before starting Fluentd:"
+  echo "  export DD_API_KEY=your_api_key_here"
+  echo ""
+  echo "Or edit fluent.conf and replace YOUR_API_KEY_HERE with your actual API key"
+  echo ""
+  if [ -t 0 ]; then
+    # Only prompt if running interactively
+    read -p "Continue anyway? (y/n) " -n 1 -r
+    echo
+    if [[ ! $REPLY =~ ^[Yy]$ ]]; then
+      exit 1
+    fi
+  else
+    echo "Non-interactive mode: Continuing with placeholder API key"
+  fi
+fi
+
+# Replace API key in config if DD_API_KEY is set
+if [ -n "$DD_API_KEY" ]; then
+  TEMP_CONFIG=$(mktemp)
+  sed "s/YOUR_API_KEY_HERE/$DD_API_KEY/g" "$CONFIG_FILE" > "$TEMP_CONFIG"
+  CONFIG_FILE="$TEMP_CONFIG"
+  trap "rm -f $TEMP_CONFIG" EXIT
+fi
+
+echo "Starting Fluentd with configuration: ${SCRIPT_DIR}/fluent.conf"
+echo "HTTP endpoint: http://localhost:8888"
+echo "Forward endpoint: localhost:24224"
+echo ""
+echo "Press Ctrl+C to stop Fluentd"
+echo ""
+
+# Start Fluentd
+bundle exec fluentd -c "$CONFIG_FILE" -v
+