run install.sh script when initialising a cluster on the init machine

internal/cli/machine.go

@@ -1,8 +1,48 @@
 package cli
 
+import (
+	"context"
+	"fmt"
+	"os"
+	"uncloud/internal/sshexec"
+)
+
+// TODO: support pinning the script version to the CLI version.
+const installScriptURL = "https://raw.githubusercontent.com/psviderski/uncloud/refs/heads/main/scripts/install.sh"
+
 type RemoteMachine struct {
 	User    string
 	Host    string
 	Port    int
 	KeyPath string
 }
+
+// provisionMachine provisions the remote machine by downloading the Uncloud install script from GitHub and running it.
+func provisionMachine(ctx context.Context, exec sshexec.Executor) error {
+	// TODO: Check if the machine is already provisioned and ask the user to reset it first.
+
+	user, err := exec.Run(ctx, "whoami")
+	if err != nil {
+		return fmt.Errorf("run whoami: %w", err)
+	}
+	sudoPrefix, env := "", ""
+	if user != "root" {
+		sudoPrefix = "sudo"
+		// Add the SSH user (non-root) to the uncloud group to allow access to the Uncloud daemon unix socket.
+		env = "UNCLOUD_GROUP_ADD_USER=" + user
+	}
+
+	fmt.Println("Downloading Uncloud install script:", installScriptURL)
+	curlBashCmd := fmt.Sprintf(
+		"curl -fsSL %s | %s %s bash", sshexec.Quote(installScriptURL), sudoPrefix, sshexec.Quote(env),
+	)
+	cmd := sshexec.QuoteCommand("bash", "-c", "set -o pipefail; "+curlBashCmd)
+	// TODO: figure out why sometimes the output of `docker version` within the script is intermixed with other
+	//  script output. Note, that the same behavior is observed when using exec.Run but not when running the script
+	//  using ssh CLI. Requesting a pseudo-terminal may help fix this issue:
+	//		session.RequestPty("xterm", 40, 80, ssh.TerminalModes{})
+	if err = exec.Stream(ctx, cmd, os.Stdout, os.Stderr); err != nil {
+		return fmt.Errorf("download and run install script: %w", err)
+	}
+	return nil
+}