chore: import upstream snapshot with attribution

cmd/micro/resource/config.go

@@ -0,0 +1,79 @@
+package resource
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/urfave/cli/v2"
+	"go-micro.dev/v6/config"
+	"go-micro.dev/v6/config/source/env"
+)
+
+// configCommand exposes the config interface: get, dump.
+//
+// The CLI loads configuration from environment variables (the source
+// that makes sense without a running service). Keys use dot notation,
+// e.g. "database.host" reads from DATABASE_HOST.
+func configCommand() *cli.Command {
+	return &cli.Command{
+		Name:  "config",
+		Usage: "Read dynamic configuration (from environment)",
+		Description: `Read dynamic configuration loaded from environment variables.
+
+Keys use dot notation: "database.host" maps to DATABASE_HOST.
+
+  micro config get <key>    Read a config value
+  micro config dump         Print the full config as JSON`,
+		Subcommands: []*cli.Command{
+			{
+				Name:      "get",
+				Usage:     "Read a config value",
+				ArgsUsage: "<key>",
+				Action:    configGet,
+			},
+			{
+				Name:   "dump",
+				Usage:  "Print the full config",
+				Action: configDump,
+			},
+		},
+	}
+}
+
+func loadConfig() (config.Config, error) {
+	conf, err := config.NewConfig()
+	if err != nil {
+		return nil, err
+	}
+	if err := conf.Load(env.NewSource()); err != nil {
+		return nil, err
+	}
+	return conf, nil
+}
+
+func configGet(c *cli.Context) error {
+	key := c.Args().First()
+	if key == "" {
+		return fail("usage: micro config get <key>")
+	}
+	conf, err := loadConfig()
+	if err != nil {
+		return fail("load config: %v", err)
+	}
+	path := strings.Split(key, ".")
+	val, err := conf.Get(path...)
+	if err != nil {
+		return fail("get %q: %v", key, err)
+	}
+	fmt.Println(string(val.Bytes()))
+	return nil
+}
+
+func configDump(c *cli.Context) error {
+	conf, err := loadConfig()
+	if err != nil {
+		return fail("load config: %v", err)
+	}
+	fmt.Println(string(conf.Bytes()))
+	return nil
+}