feat: Support configuration file for hmsecrets.

internal/clis/hmsecrets/config.go

@@ -0,0 +1,83 @@
+package hmsecrets
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"path"
+	"runtime"
+
+	"gopkg.in/yaml.v3"
+)
+
+type config struct {
+	APIBase    string `yaml:"api-base"`
+	CA         string `yaml:"ca"`
+	ClientCert string `yaml:"client-cert"`
+	ClientKey  string `yaml:"client-key"`
+}
+
+func mustLoadConfig() config {
+	var baseConfigDir string
+	var err error
+	switch runtime.GOOS {
+	case "windows":
+		fallthrough
+	case "linux":
+		baseConfigDir, err = os.UserConfigDir()
+		if err != nil {
+			panic(fmt.Errorf("determining user config dir: %w", err))
+		}
+	case "darwin":
+		// We want $HOME/.config in macOS.
+		homeDir, err := os.UserHomeDir()
+		if err != nil {
+			panic(fmt.Errorf("determining user home dir: %w", err))
+		}
+		baseConfigDir = path.Join(homeDir, ".config")
+	}
+
+	configDir := path.Join(baseConfigDir, "hmsecrets")
+
+	configBytes, err := os.ReadFile(path.Join(configDir, "config.yaml"))
+	if err != nil {
+		panic(fmt.Errorf("reading config file: %w", err))
+	}
+	var conf config
+	err = yaml.Unmarshal(configBytes, &conf)
+	if err != nil {
+		panic(fmt.Errorf("parsing config file: %w", err))
+	}
+
+	if conf.APIBase == "" {
+		panic(errors.New("api base must be present in config"))
+	}
+
+	if conf.CA == "" {
+		conf.CA = path.Join(configDir, "ca.crt")
+	}
+	if !fileAccesible(conf.CA) {
+		panic(fmt.Errorf("ca file '%s' does not exist or is inaccesible", conf.CA))
+	}
+
+	if conf.ClientCert == "" {
+		conf.ClientCert = path.Join(configDir, "client.crt")
+	}
+	if !fileAccesible(conf.ClientCert) {
+		panic(fmt.Errorf("client cert file '%s' does not exist or is inaccesible", conf.ClientCert))
+	}
+
+	if conf.ClientKey == "" {
+		conf.ClientKey = path.Join(configDir, "client.key")
+	}
+	if !fileAccesible(conf.ClientKey) {
+		panic(fmt.Errorf("client key file '%s' does not exist or is inaccesible", conf.ClientKey))
+	}
+
+	return conf
+}
+
+func fileAccesible(f string) bool {
+	_, err := os.Stat(f)
+	return err == nil
+}