chore: move cfg package to internal/cmd

internal/cmd/cli.go

@@ -0,0 +1,72 @@
+package cmd
+
+import (
+	"errors"
+	"time"
+
+	"github.com/alecthomas/kong"
+)
+
+var ErrInvalidDataURL = errors.New("invalid data url, must not be blank")
+
+type AppSettings struct {
+	ServerAddress     string
+	DataFile          string
+	DataURL           string
+	CacheTTL          time.Duration
+	ReadHeaderTimeout time.Duration
+	EnableExporter    bool
+	ExporterAddress   string
+}
+
+//nolint:lll // ignore line length
+type CLI struct {
+	ServerAddress     string `name:"listen-address" env:"GEOIP_LISTEN_ADDRESS" help:"Address to use for the api server" default:"${default_address}"`
+	DataFile          string `name:"data-file" env:"GEOIP_DATA_FILE" help:"path to data file" default:"${default_file_path}"`
+	DataURL           string `name:"data-url" env:"GEOIP_DATA_URL" help:"url to data file"`
+	CacheTTL          string `name:"cache-ttl" env:"GEOIP_CACHE_TTL" help:"ttl for response cache" default:"${default_cache_ttl}"`
+	ReadHeaderTimeout string `name:"read-header-timeout" env:"GEOIP_READ_HEADER_TIMEOUT" help:"timeout for reading http header" default:"${default_read_header_timeout}"`
+	EnableExporter    bool   `name:"enable-exporter" env:"GEOIP_ENABLE_EXPORTER" help:"enable prometheus exporter" default:"${default_enable_exporter}"`
+	ExporterAddress   string `name:"exporter-address" env:"GEOIP_EXPORTER_ADDRESS" help:"Address to use for the prometheus metrics server" default:"${default_exporter_address}"`
+}
+
+func (c *CLI) Parse() (*AppSettings, error) {
+	_ = kong.Parse(
+		c,
+		kong.Vars{
+			"default_address":             ":8080",
+			"default_file_path":           "./data.csv",
+			"default_cache_ttl":           "2m",
+			"default_read_header_timeout": "3s",
+			"default_enable_exporter":     "false",
+			"default_exporter_address":    ":9191",
+		},
+		kong.Name("country-geo-locations"),
+		kong.Description("🚀 Start a simple web server for GeoIP data"),
+		kong.UsageOnError(),
+	)
+
+	cacheTTL, err := time.ParseDuration(c.CacheTTL)
+	if err != nil {
+		return nil, err
+	}
+
+	readHeaderTimeout, err := time.ParseDuration(c.ReadHeaderTimeout)
+	if err != nil {
+		return nil, err
+	}
+
+	if c.DataURL == "" {
+		return nil, ErrInvalidDataURL
+	}
+
+	return &AppSettings{
+		ServerAddress:     c.ServerAddress,
+		DataFile:          c.DataFile,
+		DataURL:           c.DataURL,
+		CacheTTL:          cacheTTL,
+		ReadHeaderTimeout: readHeaderTimeout,
+		EnableExporter:    c.EnableExporter,
+		ExporterAddress:   c.ExporterAddress,
+	}, nil
+}