feat(embed): make authelia embedable (#8841)

This adds a highly experimental option for developers looking to embed Authelia within another go binary.

Closes #5803

Signed-off-by: James Elliott <james-d-elliott@users.noreply.github.com>

1 files changed, 64 insertions, 0 deletions

diff --git a/internal/middlewares/util.go b/internal/middlewares/util.go
index 03b80f557..7a7eb39e4 100644
--- a/internal/middlewares/util.go
+++ b/internal/middlewares/util.go
@@ -1,7 +1,26 @@
 package middlewares
 
 import (
+	"crypto/x509"
+
 	"github.com/valyala/fasthttp"
+
+	"github.com/authelia/authelia/v4/internal/authentication"
+	"github.com/authelia/authelia/v4/internal/authorization"
+	"github.com/authelia/authelia/v4/internal/clock"
+	"github.com/authelia/authelia/v4/internal/configuration/schema"
+	"github.com/authelia/authelia/v4/internal/expression"
+	"github.com/authelia/authelia/v4/internal/metrics"
+	"github.com/authelia/authelia/v4/internal/notification"
+	"github.com/authelia/authelia/v4/internal/ntp"
+	"github.com/authelia/authelia/v4/internal/oidc"
+	"github.com/authelia/authelia/v4/internal/random"
+	"github.com/authelia/authelia/v4/internal/regulation"
+	"github.com/authelia/authelia/v4/internal/session"
+	"github.com/authelia/authelia/v4/internal/storage"
+	"github.com/authelia/authelia/v4/internal/templates"
+	"github.com/authelia/authelia/v4/internal/totp"
+	"github.com/authelia/authelia/v4/internal/webauthn"
 )
 
 // SetContentTypeApplicationJSON sets the Content-Type header to `application/json; charset=utf-8`.
@@ -13,3 +32,48 @@ func SetContentTypeApplicationJSON(ctx *fasthttp.RequestCtx) {
 func SetContentTypeTextPlain(ctx *fasthttp.RequestCtx) {
 	ctx.SetContentTypeBytes(contentTypeTextPlain)
 }
+
+// NewProviders provisions all providers based on the configuration provided.
+func NewProviders(config *schema.Configuration, caCertPool *x509.CertPool) (providers Providers, warns, errs []error) {
+	providers.Random = &random.Cryptographical{}
+	providers.StorageProvider = storage.NewProvider(config, caCertPool)
+	providers.Authorizer = authorization.NewAuthorizer(config)
+	providers.NTP = ntp.NewProvider(&config.NTP)
+	providers.PasswordPolicy = NewPasswordPolicyProvider(config.PasswordPolicy)
+	providers.Regulator = regulation.NewRegulator(config.Regulation, providers.StorageProvider, clock.New())
+	providers.SessionProvider = session.NewProvider(config.Session, caCertPool)
+	providers.TOTP = totp.NewTimeBasedProvider(config.TOTP)
+	providers.UserAttributeResolver = expression.NewUserAttributes(config)
+
+	var err error
+
+	switch {
+	case config.AuthenticationBackend.File != nil:
+		providers.UserProvider = authentication.NewFileUserProvider(config.AuthenticationBackend.File)
+	case config.AuthenticationBackend.LDAP != nil:
+		providers.UserProvider = authentication.NewLDAPUserProvider(config.AuthenticationBackend, caCertPool)
+	}
+
+	if providers.Templates, err = templates.New(templates.Config{EmailTemplatesPath: config.Notifier.TemplatePath}); err != nil {
+		errs = append(errs, err)
+	}
+
+	if providers.MetaDataService, err = webauthn.NewMetaDataProvider(config, providers.StorageProvider); err != nil {
+		errs = append(errs, err)
+	}
+
+	switch {
+	case config.Notifier.SMTP != nil:
+		providers.Notifier = notification.NewSMTPNotifier(config.Notifier.SMTP, caCertPool)
+	case config.Notifier.FileSystem != nil:
+		providers.Notifier = notification.NewFileNotifier(*config.Notifier.FileSystem)
+	}
+
+	providers.OpenIDConnect = oidc.NewOpenIDConnectProvider(config, providers.StorageProvider, providers.Templates)
+
+	if config.Telemetry.Metrics.Enabled {
+		providers.Metrics = metrics.NewPrometheus()
+	}
+
+	return providers, warns, errs
+}