Move to yaml-based configuration

This commit updates the configuration to be yaml-based and updates the
configuration to read in a yaml file.

internal/config/validators/collection.go

@@ -0,0 +1,32 @@
+package validators
+
+import (
+	"github.com/FAU-CDI/wisski-distillery/pkg/environment"
+	"github.com/FAU-CDI/wisski-distillery/pkg/validator"
+)
+
+// New creates a new set of standard validators for the configuration
+func New(env environment.Environment) validator.Collection {
+	coll := make(validator.Collection)
+
+	validator.Add(coll, "nonempty", ValidateNonempty)
+
+	validator.Add(coll, "directory", func(value *string, dflt string) error {
+		return ValidateDirectory(env, value, dflt)
+	})
+	validator.Add(coll, "file", func(value *string, dflt string) error {
+		return ValidateFile(env, value, dflt)
+	})
+
+	validator.Add(coll, "domain", ValidateDomain)
+	validator.AddSlice(coll, "domains", ",", ValidateDomain)
+	validator.Add(coll, "https", ValidateHTTPSURL)
+	validator.Add(coll, "slug", ValidateSlug)
+	validator.Add(coll, "email", ValidateEmail)
+
+	validator.Add(coll, "positive", ValidatePositive)
+	validator.Add(coll, "port", ValidatePort)
+
+	validator.Add(coll, "duration", ValidateDuration)
+	return coll
+}

internal/config/validators/domain.go

@@ -0,0 +1,21 @@
+package validators
+
+import (
+	"regexp"
+	"strings"
+
+	"github.com/pkg/errors"
+)
+
+var regexpDomain = regexp.MustCompile(`^([a-zA-Z0-9][-a-zA-Z0-9]*\.)*[a-zA-Z0-9][-a-zA-Z0-9]*$`) // TODO: Make this regexp nicer!
+
+func ValidateDomain(domain *string, dflt string) error {
+	if *domain == "" {
+		*domain = dflt
+	}
+	if !regexpDomain.MatchString(*domain) {
+		return errors.Errorf("%q is not a valid domain", *domain)
+	}
+	*domain = strings.ToLower(*domain)
+	return nil
+}

internal/config/validators/duration.go

@@ -0,0 +1,14 @@
+package validators
+
+import "time"
+
+func ValidateDuration(d *time.Duration, dflt string) error {
+	if *d == 0 {
+		var err error
+		*d, err = time.ParseDuration(dflt)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}

internal/config/validators/email.go

@@ -0,0 +1,24 @@
+package validators
+
+import (
+	"regexp"
+
+	"github.com/pkg/errors"
+)
+
+var regexpEmail = regexp.MustCompile(`^([-a-zA-Z0-9]+)\@([a-zA-Z0-9][-a-zA-Z0-9]*\.)*[a-zA-Z0-9][-a-zA-Z0-9]*$`) // TODO: Make this regexp nicer!
+
+// ValidateEmail checks that s represents an email, and then returns it as is.
+func ValidateEmail(email *string, dflt string) error {
+	if *email == "" {
+		*email = dflt
+	}
+	if *email == "" { // no email provided => ok
+		return nil
+	}
+
+	if !regexpEmail.MatchString(*email) {
+		return errors.Errorf("%q is not a valid email", *email)
+	}
+	return nil
+}

internal/config/validators/files.go

@@ -0,0 +1,27 @@
+package validators
+
+import (
+	"github.com/FAU-CDI/wisski-distillery/pkg/environment"
+	"github.com/FAU-CDI/wisski-distillery/pkg/fsx"
+	"github.com/pkg/errors"
+)
+
+func ValidateFile(env environment.Environment, path *string, dflt string) error {
+	if *path == "" {
+		*path = dflt
+	}
+	if !fsx.IsFile(env, *path) {
+		return errors.Errorf("%q does not exist or is not a file", *path)
+	}
+	return nil
+}
+
+func ValidateDirectory(env environment.Environment, path *string, dflt string) error {
+	if *path == "" {
+		*path = dflt
+	}
+	if !fsx.IsDirectory(env, *path) {
+		return errors.Errorf("%q does not exist or is not a directory", *path)
+	}
+	return nil
+}

internal/config/validators/int.go

@@ -0,0 +1,32 @@
+package validators
+
+import (
+	"strconv"
+
+	"github.com/pkg/errors"
+)
+
+func ValidatePositive(value *int, dflt string) (err error) {
+	if *value == 0 && dflt != "" {
+		v, err := strconv.ParseInt(dflt, 10, 64)
+		if err != nil {
+			return err
+		}
+		*value = int(v)
+	}
+	if *value <= 0 {
+		return errors.Errorf("%d is not a positive value", *value)
+	}
+	return nil
+}
+
+func ValidatePort(value *uint16, dflt string) (err error) {
+	if *value == 0 && dflt != "" {
+		v, err := strconv.ParseUint(dflt, 10, 16)
+		if err != nil {
+			return err
+		}
+		*value = uint16(v)
+	}
+	return nil
+}

internal/config/validators/slug.go

@@ -0,0 +1,24 @@
+package validators
+
+import (
+	"regexp"
+	"strings"
+
+	"github.com/pkg/errors"
+)
+
+var regexpSlug = regexp.MustCompile(`^[a-zA-Z0-9][-a-zA-Z0-9]*$`) // TODO: Make this regexp nicer!
+
+var ErrInvalidSlug = errors.New("invalid slug")
+
+// ValidateSlug validates a slug and normalizes it.
+func ValidateSlug(s *string, dflt string) error {
+	if *s == "" {
+		*s = dflt
+	}
+	*s = strings.ToLower(*s)
+	if !regexpSlug.MatchString(*s) {
+		return ErrInvalidSlug
+	}
+	return nil
+}

internal/config/validators/string.go

@@ -0,0 +1,16 @@
+package validators
+
+import "github.com/pkg/errors"
+
+var errEmpty = errors.New("value is empty")
+
+func ValidateNonempty(value *string, dflt string) error {
+	if *value == "" {
+		*value = dflt
+	}
+
+	if *value == "" {
+		return errEmpty
+	}
+	return nil
+}

internal/config/validators/url.go

@@ -0,0 +1,46 @@
+package validators
+
+import (
+	"net/url"
+
+	"github.com/pkg/errors"
+)
+
+// URL represents a url.URL that is marshaled as a string representing the url.
+type URL url.URL
+
+func (u *URL) MarshalText() (text []byte, err error) {
+	return []byte(u.String()), nil
+}
+
+func (u *URL) String() string {
+	if u == nil {
+		return ""
+	}
+	return (*url.URL)(u).String()
+}
+
+func (u *URL) UnmarshalText(text []byte) error {
+	if len(text) == 0 {
+		return nil
+	}
+	pu, err := url.Parse(string(text))
+	if err != nil {
+		return err
+	}
+	*u = URL(*pu)
+	return nil
+}
+
+func ValidateHTTPSURL(url **URL, dflt string) error {
+	if (*url).String() == "" {
+		*url = new(URL)
+		if err := (*url).UnmarshalText([]byte(dflt)); err != nil {
+			return err
+		}
+	}
+	if (*url).Scheme != "https" {
+		return errors.Errorf("%q is not a valid https URL (%q)", *url, (*url).Scheme)
+	}
+	return nil
+}