Add README and upgrade Java version to 21 (#1)

- Added comprehensive `README.md` with setup, usage instructions, and troubleshooting.
- Updated Java toolchain to require Java 21 (from Java 17).

Author: isaric

.idea/misc.xml

@@ -0,0 +1,106 @@
+# DashboardSummary
+
+A small Java service that periodically queries InfluxDB metrics, asks Google Gemini to produce a short human‑friendly summary (2–4 sentences), and writes that summary back to InfluxDB for display on dashboards.
+
+## Features
+- Pulls metrics from InfluxDB with configurable measurement/field filters
+- Aggregates over a fixed time window (mean/min/max/last)
+- Sends a compact JSON payload to Gemini with optional system instruction
+- Writes the generated summary to an output measurement in the same bucket
+- Can run once (batch mode) or on a fixed schedule
+
+## Requirements
+- Java 21+ (the Docker image uses Temurin 21 JRE but the app targets 17)
+- InfluxDB 2.x with an API token and bucket/org
+- Google Generative Language (Gemini) API key
+- Gradle (wrapper included)
+
+Configuration (Environment Variables)
+The application reads configuration from environment variables at startup.
+
+### Required
+- `INFLUX_URL`: URL of InfluxDB (e.g., http://localhost:8086)
+- `INFLUX_TOKEN`: InfluxDB API token with read/write access to the bucket
+- `INFLUX_ORG`: InfluxDB organization name/ID
+- `INFLUX_BUCKET`: InfluxDB bucket name
+- `GOOGLE_API_KEY`: Google Gemini API key
+
+### Optional (with defaults)
+- `INFLUX_MEASUREMENT_REGEX`: Regex for measurements to include (default: .*)
+- `INFLUX_FIELD_REGEX`: Regex for fields to include (default: unset = all fields)
+- `GOOGLE_MODEL`: Gemini model (default: gemini-2.5-flash)
+- `OUTPUT_MEASUREMENT`: Measurement to write summaries to (default: dashboard_summary)
+- `INTERVAL_MINUTES`: Window size and schedule period in minutes (default: 15)
+- `TIMEZONE`: IANA timezone for scheduling (default: system timezone)
+- `RUN_ONCE`: If true, runs a single cycle and exits (default: false)
+- `SYSTEM_INSTRUCTION`: System prompt sent to Gemini (default: "You are a concise observability assistant.")
+
+## Quick start (local)
+### 1) Export environment variables (example)
+
+
+     export INFLUX_URL="http://localhost:8086"
+     export INFLUX_TOKEN="<your-token>"
+     export INFLUX_ORG="<your-org>"
+     export INFLUX_BUCKET="<your-bucket>"
+     export GOOGLE_API_KEY="<your-gemini-api-key>"
+
+#### Optional filters and settings
+
+    export INFLUX_MEASUREMENT_REGEX="^telemetry_.*$"
+    export INFLUX_FIELD_REGEX="^(temperature|humidity)$"
+    export INTERVAL_MINUTES=15
+    export RUN_ONCE=false
+
+### 2) Build and run with Gradle
+    ./gradlew run
+
+   To build a distribution you can run:
+
+    ./gradlew installDist
+    ./build/install/DashboardSummary/bin/DashboardSummary
+
+## Run once (batch mode)
+Set `RUN_ONCE=true` to execute a single summary cycle and exit.
+
+    RUN_ONCE=true ./gradlew run
+   # or with the installed distribution
+    RUN_ONCE=true ./build/install/DashboardSummary/bin/DashboardSummary
+
+## Docker
+Build the image (multi-stage Dockerfile provided):
+
+    docker build -t dashboard-summary:latest .
+
+Run the container (pass env variables):
+
+    docker run --rm \
+     -e INFLUX_URL=http://influxdb:8086 \
+     -e INFLUX_TOKEN=YOUR_TOKEN \
+     -e INFLUX_ORG=YOUR_ORG \
+     -e INFLUX_BUCKET=YOUR_BUCKET \
+     -e GOOGLE_API_KEY=YOUR_GEMINI_KEY \
+     -e INFLUX_MEASUREMENT_REGEX=".*" \
+     -e INTERVAL_MINUTES=15 \
+     -e OUTPUT_MEASUREMENT=dashboard_summary \
+     --name dashboard-summary dashboard-summary:latest
+
+## How it works
+- For the last `INTERVAL_MINUTES`, the app queries InfluxDB for each matching measurement/field and computes mean, min, max, and last values.
+- It composes a compact JSON payload with these stats and asks Gemini to write a short summary.
+- The summary is written back to InfluxDB in `OUTPUT_MEASUREMENT` with fields: text (string) and interval_minutes (int), and tag: model.
+
+## Notes and tips
+- Ensure the Influx token has read permission for source measurement(s) and write permission for `OUTPUT_MEASUREMENT` in the target bucket.
+- `TIMEZONE` only affects when periodic runs are scheduled; the data range is relative to "now" per InfluxDB.
+- If you need stricter control over prompting, set `SYSTEM_INSTRUCTION` to guide the model’s tone and focus.
+
+## Troubleshooting
+- Missing configuration: the app logs a clear list of missing variables and exits with code 1.
+- Gemini API errors: you will see the HTTP status and body in logs; verify `GOOGLE_API_KEY` and model.
+- Influx query failures: the app logs a warning per failed query and continues with available data.
+
+## Development
+- Build and test: ./gradlew build
+- Code entry point: com.pathvariable.smartgarden.summary.Main
+- Key classes: Config, GeminiClient, SummaryJob, TimeUtil, MetricKey

README.md

@@ -8,7 +8,7 @@ version = '1.0-SNAPSHOT'
 
 java {
     toolchain {
-        languageVersion = JavaLanguageVersion.of(17)
+        languageVersion = JavaLanguageVersion.of(21)
     }
 }