chore: updated github workflow

.github/workflows/release.yaml

@@ -12,12 +12,12 @@ jobs:
             contents: write
         steps:
             - name: Checkout Repository
-              uses: actions/checkout@v2
+              uses: actions/checkout@v4
 
             - name: Set up Go
-              uses: actions/setup-go@v2
+              uses: actions/setup-go@v4
               with:
-                  go-version: 1.21
+                  go-version-file: './go.mod'
 
             - name: Build
               run: |

README.md

@@ -1,64 +1,76 @@
 # Go Stats Server
 
-This Go project implements a simple TCP server that responds to custom commands over the network. The server performs various system-related tasks and provides
-information such as CPU usage, memory status, network statistics, storage details, and system uptime.
+This Go project implements a simple TCP server that responds to custom commands over an internal network. The server performs various system-related tasks and provides information such as CPU usage, memory status, network statistics, storage details, and system uptime.
+
+## Commands
+
+The protocol supports the following commands: 
+
+- `cpu` — returns the CPU usage percentage
+- `memory` — returns the memory usage in MB
+- `network` — returns the network usage in bytes
+- `storage` — returns the storage usage in GB
+- `uptime` — returns the system uptime in seconds
+
+[TODO: check if the command docs are correct]
 
 ## Usage
 
 1. **Build the Server:**
 
-    ```bash
-    CGO_ENABLED=0 GOARCH=<arch> go build -a -ldflags '-s -w' -o ./out/stats-server main.go
+    ```bash shell
+    $ CGO_ENABLED=0 GOARCH=<arch> go build -a -ldflags '-s -w' -o ./out/stats-server main.go
     ```
 
 2. **Run the Server:**
 
-    ```bash
-    ./out/stats-server
+    ```bash shell
+    $ ./out/stats-server serve
     ```
 
-3. **Connect to the Server:** Use a TCP client to connect to the server on port 12345. You can send commands like "cpu," "memory," "network," "storage,"
-   "uptime," and "exit."
+3. **Connect to the Server:** Use a TCP client to connect to the server on port 12345. You can send commands like "cpu", "memory", "network", "storage" or
+   "uptime".
 
     Example using `nc`:
 
-    ```bash
-    echo "cpu" | nc localhost 12345
+    ```bash shell
+    $ time ( echo "cpu" | nc <hostname> 12345 )
     ```
 
-    or using golang
+    or directly using golang:
 
     ```go
-    import "net"
+    conn, _ := net.Dial("tcp", "<hostname>:12345")
+    conn.Write([]byte("cpu\n"))
 
-    func main() {
-        conn, err := net.Dial("tcp", "localhost:12345")
-        if err != nil {
-            // handle error
-        }
-        defer conn.Close()
-
-        conn.Write([]byte("cpu"))
-    }
+    data, _ := io.RealAll(conn)
+    log.Printf("data: %s", data)
     ```
 
 ## GitHub Actions Workflow
 
-The included GitHub Actions workflow automates the build and release process. On each push to the main branch, the workflow builds the Go program, creates a
-GitHub release, and uploads the compiled binary as an artifact.
+The included GitHub Actions workflow automates the build and release process. On each push to the main branch, the workflow builds the Go program, creates a GitHub release, and uploads the compiled binary as an artifact.
 
-## Downloading the Artifact
+## Self-Installing Binary
 
-TODO
-
-<!--
-To download the compiled binary on multiple machines using GNU Parallel, use the following `wget` command:
+Assuming you have a cluster of machines, you can use the following commands to download, install and setup systemd services for the latest version of the binary on all nodes. You must have root access to all nodes.
 
 ```bash
-cat machines.txt | parallel --slf - 'wget -qO- https://github.com/aziis98/go-stats-server/releases/latest/download/stats-server | tar -xz -C /path/to/destination/'
+$ parallel --nonall --slf nodes.txt 'mkdir -p cluster'
+$ parallel --nonall --slf nodes.txt 'wget -qO- https://github.com/aziis98/go-stats-server/releases/latest/download/stats-server > ./cluster/stats-server'
+$ parallel --nonall --slf nodes.txt 'chmod -v +x ./cluster/stats-server'
+
+# setup systemd services on all nodes
+$ parallel --nonall --slf nodes.txt './cluster/stats-server setup'
+
+# setup systemd service on a single node
+$ ssh root@<node>
+$ cd cluster
+$ ./stats-server setup
+
+# trying out the new binary using netcat
+$ time ( echo '<command>' | nc <node> 12345 )
+
+# stop and disable the systemd service on all nodes
+$ parallel --nonall --slf nodes.txt 'systemctl disable --now stats-server.service'
 ```
-
-Replace "your-username" and "your-repo" with your GitHub username and repository name. Adjust "/path/to/destination/" to the desired destination on the target machines.
-
-Feel free to explore and customize the server to suit your needs. If you encounter any issues or have suggestions for improvements, please open an issue on this repository. Contributions are welcome!
--->

main.go

@@ -78,22 +78,25 @@ func handleConnection(conn net.Conn) {
 
 func runCommand(args ...string) error {
 	cmd := exec.Command(args[0], args[1:]...)
-	if err := cmd.Run(); err != nil {
-		return err
+
+	if output, err := cmd.CombinedOutput(); err != nil {
+		return fmt.Errorf("%w: %s", err, output)
 	}
 
 	return nil
 }
 
 func setupSystemdService() error {
-	// copy itself to /usr/bin
+	if _, err := os.Stat("/usr/local/bin/stats-server"); err == nil {
+		log.Println("binary already exists in /usr/local/bin, updating...")
+	}
+
 	log.Println("copying itself to /usr/local/bin/stats-server")
-	if err := runCommand("cp", os.Args[0], "/usr/local/bin/stats-server"); err != nil {
+	if err := runCommand("cp", "-f", os.Args[0], "/usr/local/bin/stats-server"); err != nil {
 		return err
 	}
 
-	// write systemd service unit
-	log.Println("generating /etc/systemd/system/stats-server.service")
+	log.Println("writing unit to /etc/systemd/system/stats-server.service")
 	if err := os.WriteFile(
 		"/etc/systemd/system/stats-server.service",
 		[]byte(systemdServiceUnit),
@@ -102,15 +105,18 @@ func setupSystemdService() error {
 		return err
 	}
 
-	// reload systemd
 	log.Println("running systemctl daemon-reload")
 	if err := runCommand("systemctl", "daemon-reload"); err != nil {
 		return err
 	}
 
-	// enable and start the service
-	log.Println("running systemctl enable --now stats-server.service")
-	if err := runCommand("systemctl", "enable", "--now", "stats-server.service"); err != nil {
+	log.Println("running systemctl enable stats-server.service")
+	if err := runCommand("systemctl", "enable", "stats-server.service"); err != nil {
+		return err
+	}
+
+	log.Println("running systemctl (re)start stats-server.service")
+	if err := runCommand("systemctl", "restart", "stats-server.service"); err != nil {
 		return err
 	}
 
@@ -142,11 +148,29 @@ func startTCPServer() error {
 	}
 }
 
-func showHelp() {
-	fmt.Println("usage: stats-server [setup|serve]")
-	fmt.Println("  setup: setup systemd service")
-	fmt.Println("  serve: start tcp server")
+var helpText = strings.TrimSpace(`
+usage: stats-server [setup|serve]
 
+This is a simple tcp server that returns system stats, it can be run as a
+systemd service or as a standalone server.
+
+protocol commands:
+    cpu      returns cpu usage
+    memory   returns memory usage
+    network  returns network usage
+    storage  returns storage usage
+    uptime   returns uptime
+
+subcommands:
+    setup    auto-install and setup systemd service
+    serve    start tcp server
+
+config, environment variables:
+    HOST     tcp host to bind to (default: :12345)
+`)
+
+func showHelp() {
+	fmt.Println(helpText)
 	os.Exit(1)
 }
 
@@ -157,17 +181,21 @@ func main() {
 
 	switch os.Args[1] {
 	case "setup":
+		log.Println("starting setup")
 		if err := setupSystemdService(); err != nil {
 			log.Fatal(err)
 		}
 
-		log.Println("setup complete")
+		log.Println("setup completed")
+
 	case "serve":
+		log.Println("starting server")
 		if err := startTCPServer(); err != nil {
 			log.Fatal(err)
 		}
 
 		log.Println("server exited")
+
 	default:
 		showHelp()
 	}