add api/v1/instance info handler + instance model (#18)

internal/api/client/instance/instance.go

@@ -0,0 +1,38 @@
+package instance
+
+import (
+	"net/http"
+
+	"github.com/sirupsen/logrus"
+	"github.com/superseriousbusiness/gotosocial/internal/api"
+	"github.com/superseriousbusiness/gotosocial/internal/config"
+	"github.com/superseriousbusiness/gotosocial/internal/message"
+	"github.com/superseriousbusiness/gotosocial/internal/router"
+)
+
+const (
+	// InstanceInformationPath
+	InstanceInformationPath = "api/v1/instance"
+)
+
+// Module implements the ClientModule interface
+type Module struct {
+	config    *config.Config
+	processor message.Processor
+	log       *logrus.Logger
+}
+
+// New returns a new instance information module
+func New(config *config.Config, processor message.Processor, log *logrus.Logger) api.ClientModule {
+	return &Module{
+		config:    config,
+		processor: processor,
+		log:       log,
+	}
+}
+
+// Route satisfies the ClientModule interface
+func (m *Module) Route(s router.Router) error {
+	s.AttachHandler(http.MethodGet, InstanceInformationPath, m.InstanceInformationGETHandler)
+	return nil
+}