Initial QSfera import

Server/services/webfinger/pkg/service/v0/service.go

@@ -0,0 +1,105 @@
+package service
+
+import (
+	"context"
+	"net/url"
+
+	"github.com/qsfera/server/pkg/log"
+	"github.com/qsfera/server/services/webfinger/pkg/config"
+	"github.com/qsfera/server/services/webfinger/pkg/webfinger"
+)
+
+// Service defines the extension handlers.
+type Service interface {
+	// Webfinger is the endpoint for retrieving various href relations.
+	//
+	//	GET /.well-known/webfinger?
+	//	     resource=acct%3Acarol%40example.com&
+	//	     rel=http%3A%2F%2Fwebfinger.qsfera%rel%2Fserver-instance
+	//	     HTTP/1.1
+	//	Host: example.com
+	//
+	// The server might respond like this:
+	//
+	//	HTTP/1.1 200 OK
+	//	Access-Control-Allow-Origin: *
+	//	Content-Type: application/jrd+json
+	//
+	//	{
+	//	  "subject" : "acct:carol@example.com",
+	//	  "links" :
+	//	  [
+	//	    {
+	//	      "rel" : "http://webfinger.qsfera/rel/server-instance",
+	//	      "href" : "https://instance.example.com",
+	//	      "titles": {
+	//	        "en": "Readable Instance Name"
+	//	      }
+	//	    },
+	//	    {
+	//	      "rel" : "http://webfinger.qsfera/rel/server-instance",
+	//	      "href" : "https://otherinstance.example.com",
+	//	      "titles": {
+	//	        "en": "Other Readable Instance Name"
+	//	      }
+	//	    }
+	//	  ]
+	//	}
+	Webfinger(ctx context.Context, queryTarget *url.URL, rels []string, platform string) (webfinger.JSONResourceDescriptor, error)
+}
+
+type RelationProvider interface {
+	Add(ctx context.Context, platform string, jrd *webfinger.JSONResourceDescriptor)
+}
+
+// New returns a new instance of Service
+func New(opts ...Option) (Service, error) {
+	options := newOptions(opts...)
+
+	// TODO use fallback implementations of InstanceIdLookup and InstanceLookup?
+	// The InstanceIdLookup may have to happen earlier?
+
+	return svc{
+		log:               options.Logger,
+		config:            options.Config,
+		relationProviders: options.RelationProviders,
+	}, nil
+}
+
+type svc struct {
+	config            *config.Config
+	log               log.Logger
+	relationProviders map[string]RelationProvider
+}
+
+// TODO implement different implementations:
+// static one returning the href or a configurable domain
+// regex one returning different instances based on the regex that matches
+// claim one that reads a claim and then fetches the instance?
+// that is actually two interfaces / steps:
+// - one that determines the instances/schools id (read from claim, regex match)
+// - one that looks up in instance by id (use template, read from json, read from ldap, read from graph)
+
+// Webfinger implements the service interface
+func (s svc) Webfinger(ctx context.Context, queryTarget *url.URL, rel []string, platform string) (webfinger.JSONResourceDescriptor, error) {
+
+	jrd := webfinger.JSONResourceDescriptor{
+		Subject: queryTarget.String(),
+	}
+
+	if len(rel) == 0 {
+		// add all configured relation providers
+		for _, relation := range s.relationProviders {
+			relation.Add(ctx, platform, &jrd)
+		}
+	} else {
+		// only add requested relations
+		for _, r := range rel {
+			if relation, ok := s.relationProviders[r]; ok {
+				relation.Add(ctx, platform, &jrd)
+			}
+		}
+	}
+
+	return jrd, nil
+}