Add README (#5)

.github/workflows/release.yml

@@ -28,7 +28,9 @@ jobs:
         with:
           context: .
           file: ./build/Dockerfile
-          tags: ghcr.io/maxitosh/ton-node-exporter:${{ github.ref_name }}
+          tags: |
+            ghcr.io/maxitosh/ton-node-exporter:${{ github.ref_name }}
+            ghcr.io/maxitosh/ton-node-exporter:latest
           push: true
           labels: |
             org.opencontainers.image.source=${{ github.repository }}

README.md

@@ -1,2 +1,96 @@
 # ton-node-exporter
-A Prometheus metrics exporter for The Open Network (TON) Node.
+
+A Prometheus metrics exporter for The Open Network (TON) Node.  
+TON Node does not provide any built-in metrics for monitoring, so this exporter was created to fill that gap.
+
+## Prerequisites
+- Go 1.22 or later
+- Docker (optional)
+- Access to a TON Lite Server (Node) with a valid key.
+
+## Installation
+### From source
+To build and install the exporter from source, follow these steps:
+```bash
+git clone https://github.com/Maxitosh/ton-node-exporter.git
+cd ton-node-exporter
+go build -o ton-node-exporter ./cmd/ton-node-exporter
+```
+
+### Docker
+To pull the Docker image, use the following command:
+```bash
+docker pull ghcr.io/maxitosh/ton-node-exporter:latest
+```
+
+## Usage
+### Configuration
+The exporter is configured using environment variables or a `.env` file. The following variables are available:
+
+- `EXPORTER_PORT`: The port on which the exporter will listen (default: `9100`).
+- `LITE_SERVER_ADDR`: The address of the TON Lite Server (Node) to monitor.
+- `LITE_SERVER_KEY`: The key to access the TON Lite Server.
+- `GLOBAL_CONFIG_URL`: The URL of the TON global lite server config.
+
+Check the .env.template file for an example and relevant environment variables. To create a .env file, copy the template:
+```bash
+cp .env.template .env
+```
+
+## Running
+### From source
+Assuming you set up the environment variables in the `.env` file, you can run the exporter with the following command:
+```bash
+./ton-node-exporter
+```
+If you want to use environment variables instead of a `.env` file, you can run the exporter like this:
+```bash
+export EXPORTER_PORT=9100
+export LITE_SERVER_ADDR=""
+export LITE_SERVER_KEY=""
+export GLOBAL_CONFIG_URL=""
+./ton-node-exporter
+```
+
+### Docker
+To run the exporter using Docker:
+```bash
+docker run -d --name ton-node-exporter --env-file .env -p 9100:9100 ghcr.io/maxitosh/ton-node-exporter:latest
+```
+
+## Metrics
+The exporter exposes the following metrics:
+
+| Metric name                        | Metric type | Description                                                                 | Labels/tags | Status |  
+|------------------------------------|-------------|-----------------------------------------------------------------------------|-------------|--------|  
+| ton_node_master_chain_block_number | Gauge       | The current master chain block number.                                      | env         | ✅      |
+| ton_node_head_lag                  | Gauge       | The lag between the current master chain block on the node and the network. | env         | ✅      |
+
+## Testing
+To run tests, execute the following command:
+```bash
+go test -v ./...
+```
+
+## Examples
+To access the metrics, do curl request to the exporter:
+```bash
+curl http://localhost:9100/metrics
+```
+Response:
+```plaintext
+...
+# HELP ton_node_head_lag Head block lag
+# TYPE ton_node_head_lag gauge
+ton_node_head_lag 0
+# HELP ton_node_master_chain_block_number Master chain block number
+# TYPE ton_node_master_chain_block_number gauge
+ton_node_master_chain_block_number{env="global"} 3.9033746e+07
+ton_node_master_chain_block_number{env="local"} 3.9033746e+07
+```
+
+## Contributing
+Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.
+
+## Author
+Created by [Maxitosh (Max Kureikin)](https://github.com/Maxitosh).