uncloud CLI tool and 'machine add' command to bootstrap a new cluster

internal/cli/config/config.go

@@ -0,0 +1,63 @@
+package config
+
+import (
+	"fmt"
+	"github.com/BurntSushi/toml"
+	"os"
+	"path/filepath"
+)
+
+type Config struct {
+	Clusters       map[string]*Cluster `toml:"clusters"`
+	CurrentCluster string              `toml:"current_cluster"`
+
+	// path is the file path config is read from.
+	path string
+}
+
+func NewFromFile(path string) (*Config, error) {
+	_, err := os.Stat(path)
+	if err != nil && !os.IsNotExist(err) {
+		return nil, fmt.Errorf("check file permissions %q: %w", path, err)
+	}
+	c := &Config{
+		Clusters: map[string]*Cluster{},
+		path:     path,
+	}
+	if os.IsNotExist(err) {
+		return c, nil
+	}
+
+	if err = c.Read(); err != nil {
+		return nil, err
+	}
+	return c, nil
+}
+
+func (c *Config) Read() error {
+	_, err := toml.DecodeFile(c.path, c)
+	if err != nil {
+		return fmt.Errorf("read config file %q: %w", c.path, err)
+	}
+	return nil
+}
+
+func (c *Config) Save() error {
+	dir, _ := filepath.Split(c.path)
+	if err := os.MkdirAll(dir, 0700); err != nil {
+		return fmt.Errorf("create config directory %q: %w", dir, err)
+	}
+
+	f, err := os.OpenFile(c.path, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0600)
+	if err != nil {
+		return fmt.Errorf("write config file %q: %w", c.path, err)
+	}
+
+	encoder := toml.NewEncoder(f)
+	encoder.Indent = ""
+	if err = encoder.Encode(c); err != nil {
+		_ = f.Close()
+		return fmt.Errorf("encode config file %q: %w", c.path, err)
+	}
+	return f.Close()
+}