tonyslist/config/config.go

package config

import (
	"path/filepath"
	"time"

	"github.com/spf13/viper"
)

const (
	migrationsDir = "db/migrations"

	// templateDir stores the name of the directory that contains templates
	templateDir = "templates"

	// TemplateExt stores the extension used for the template files
	TemplateExt = ".gohtml"

	// staticDir stores the name of the directory that will serve static files
	staticDir = "static"

	// StaticPrefix stores the URL prefix used when serving static files
	StaticPrefix = "files"

	// UserContentPrefix stores the URL prefix used when service static files that were uploaded by users.
	UserContentPrefix = "usercontent"
)

type environment string

const (
	// EnvLocal represents the local environment
	EnvLocal environment = "local"

	// EnvTest represents the test environment
	EnvTest environment = "test"

	// EnvProduction represents the production environment
	EnvProduction environment = "prod"
)

// builtinDirectoryPath returns the path to a directory depending on whether the
// app is running in production or not. During development and testing it is
// assumed that the directory is contained in the root directory. During
// production it should be at the filesystem root since it will be included in
// the container at build time.
func builtinDirectoryPath(cfg *Config, dirname string) string {
	if cfg.App.Environment == EnvProduction {
		return "/" + dirname
	}
	return filepath.Join(cfg.Storage.RootDir, dirname)
}

func StaticDir(cfg *Config) string {
	return builtinDirectoryPath(cfg, staticDir)
}

func TemplateDir(cfg *Config) string {
	return builtinDirectoryPath(cfg, templateDir)
}

func MigrationsDir(cfg *Config) string {
	return builtinDirectoryPath(cfg, migrationsDir)
}

type (
	// Config stores complete configuration
	Config struct {
		HTTP      HTTPConfig
		App       AppConfig
		Flags     FlagsConfig
		Cache     CacheConfig
		Storage   StorageConfig
		Mail      MailConfig
		Mapbox    MapboxConfig
		Discourse DiscourseConfig
		Wiki      WikiConfig
		Stripe    StripeConfig
	}

	// HTTPConfig stores HTTP configuration
	HTTPConfig struct {
		Hostname     string
		Port         uint16
		ReadTimeout  time.Duration
		WriteTimeout time.Duration
		IdleTimeout  time.Duration
		TLS          struct {
			Enabled     bool
			Certificate string
			Key         string
		}
	}

	// AppConfig stores application configuration
	AppConfig struct {
		Name        string
		Environment environment
		// Location is the IANA timezone database name where the users are located.
		// This assumes that the application serves a narrow geographical area.
		Location string
		// Loc is the parsed Location
		Loc *time.Location
		// Should include the protocol but not the trailing slash.
		PublicURL string
		// THIS MUST BE OVERRIDDEN ON ANY LIVE ENVIRONMENTS
		EncryptionKey                    string
		Timeout                          time.Duration
		EmailVerificationTokenExpiration time.Duration

		// MaxWorkers defines the maximum number of workers that will be created
		// in the worker pool for async tasks.
		MaxWorkers int

		// MetricsPort is the port on which Prometheus metrics will be served.
		MetricsPort uint16

		// HooksUsername is the basic auth username which protects the hooks endpoints
		HooksUsername string

		// HooksPassword string is the basic auth password which protects the hooks endpoints
		HooksPassword string
	}

	FlagsConfig struct{}

	// CacheConfig stores the cache configuration
	// TODO: Tune these
	CacheConfig struct {
		NumCounters int64
		MaxCost     int64
		BufferItems int64
		Expiration  struct {
			StaticFile time.Duration
			Page       time.Duration
		}
	}

	// Storage stores the configuration for different types of storage. The
	// template and static file directories are not included here because their
	// location is predefined at the root of the container when running in
	// production and
	StorageConfig struct {
		// PhotoStorageDir is the path relative to RootDir where uploaded
		// photos are stored until they can be converted and stored in the database.
		PhotoStorageDir string

		// DatabaseFile is the absolute path to the database sqlite file.
		DatabaseFile string

		// RBACPolicyPath is the path relative to the root dir containing the policy csv.
		RBACPolicyPath string

		// RootDir is the absolute path to the directory where the templates,
		// db, and static directories can be found. This setting will default to
		// "/" when not set, and should not be set in production.
		RootDir string
	}

	// MailConfig stores the mail configuration
	MailConfig struct {
		// ConfigurePostmark controls whether the application will attempt to
		// configure the Postmark provider by creating the message streams and
		// webhooks.
		ConfigurePostmark bool

		Token  string
		Enable bool

		// Domain is the part after the @ where this application is listening for emails.
		// It is used for anonymous email addresses on classified posts.
		Domain string

		// FromAddress is the email address used to send emails from the app.
		FromAddress string

		// DigestsAddress is the email used to send the twice weekly email digests.
		DigestsAddress string

		// SupportAddress is the address which users send to when they need support.
		// Emails received for this address will be forwarded to the AdminAddress.
		SupportAddress string

		// EventsAddress is the address used for RSVPs on events.
		EventsAddress string

		// AdminAddress is the address which incoming emails that are for an unknown address for for support are forwarded to.
		// It should be a real mailbox, not the email provider used by this app, otherwise a loop will occur.
		AdminAddress string
	}

	// MapboxConfig stores the configuration for interacting with Mapbox
	MapboxConfig struct {
		Token string

		// BoundingBox is a string such as "-123.0414,48.5843,-122.7352,48.7191"
		// which denotes the minimum area that should be included in the map
		// image retrieved.
		//
		// The bounding box is also used to restrict address lookups.
		BoundingBox string

		// Resolution is a string such as "560x420" which determines the
		// resolution of the image retrieved from MapBox.
		Resolution string
	}

	DiscourseConfig struct {
		// ClientID is the OAuth2 client_id used by Discourse to connect to this server.
		ClientID string

		// ClientSecret is the OAuth2 client_secret used by Discourse to connect to this server.
		ClientSecret string

		// Domain is the domain Discourse is accessible on.
		Domain string
	}

	// Parameters are the same as for the DiscourseConfig.
	WikiConfig struct {
		ClientID     string
		ClientSecret string
		Domain       string
	}

	StripeConfig struct {
		SecretKey      string
		PublishableKey string

		// ID of the subscription product in Stripe. This is used for creating
		// custom subscription amounts.
		SubscriptionIDProduct string

		// ID of the $5/yr subscription in Stripe.
		SubscriptionID5 string

		// ID of the $10/yr subscription in Stripe.
		SubscriptionID10 string

		// ID of the $25/yr subscription in Stripe.
		SubscriptionID25 string
	}
)

// GetConfig loads and returns configuration
func GetConfig(configFilePath string) (Config, error) {
	viper.SetConfigFile(configFilePath)

	configDir := filepath.Dir(configFilePath)
	viper.SetDefault("storage.rootDir", configDir)
	viper.SetDefault("storage.DatabaseFile", "data.sqlite")
	viper.SetDefault("storage.PhotoStorageDir", "storage")

	var c Config
	if err := viper.ReadInConfig(); err != nil {
		return c, err
	}

	if err := viper.Unmarshal(&c); err != nil {
		return c, err
	}

	var err error
	c.App.Loc, err = time.LoadLocation(c.App.Location)
	if err != nil {
		return c, err
	}

	// TODO: Check for required config values

	return c, nil
}