example: add sub-delegation

toolkit/_example/bob-client/bob.go

@@ -0,0 +1,111 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"log"
+	"net/http"
+	"net/url"
+	"os"
+	"os/signal"
+	"syscall"
+	"time"
+
+	"github.com/ucan-wg/go-ucan/did"
+	"github.com/ucan-wg/go-ucan/pkg/command"
+	"github.com/ucan-wg/go-ucan/pkg/container"
+
+	example "github.com/INFURA/go-ucan-toolkit/_example"
+	protocol "github.com/INFURA/go-ucan-toolkit/_example/_protocol-issuer"
+	"github.com/INFURA/go-ucan-toolkit/client"
+	"github.com/INFURA/go-ucan-toolkit/server/bearer"
+)
+
+func main() {
+	ctx, cancel := context.WithCancel(context.Background())
+
+	// register as handler of the interrupt signal to trigger the teardown
+	quit := make(chan os.Signal, 1)
+	signal.Notify(quit, syscall.SIGINT, syscall.SIGTERM, os.Interrupt)
+
+	go func() {
+		<-quit
+		cancel()
+	}()
+
+	err := run(ctx, example.AliceIssuerUrl, example.AliceDid, example.ServiceUrl, example.ServiceDid)
+	if err != nil {
+		log.Println(err)
+		os.Exit(1)
+	}
+}
+
+func run(ctx context.Context, aliceUrl string, aliceDid did.DID, serverUrl string, serviceDid did.DID) error {
+	// Let's generate a keypair for our client:
+	priv, d, err := did.GenerateEd25519()
+	if err != nil {
+		return err
+	}
+
+	log.Printf("Bob DID is %s", d.String())
+
+	cli, err := client.NewClient(priv, protocol.NewRequester(aliceUrl))
+	if err != nil {
+		return err
+	}
+
+	for {
+		proofs, err := cli.PrepareInvoke(ctx, command.MustParse("/foo/bar"), serviceDid)
+		if err != nil {
+			return err
+		}
+
+		err = makeRequest(ctx, d, serverUrl, aliceDid, proofs)
+		if err != nil {
+			log.Println(err)
+		}
+
+		select {
+		case <-ctx.Done():
+			return nil
+		case <-time.After(5 * time.Second):
+		}
+	}
+}
+
+func makeRequest(ctx context.Context, clientDid did.DID, serviceUrl string, aliceDid did.DID, proofs container.Writer) error {
+	// we construct a URL that include the our DID and Alice DID as path, as requested by the UCAN policy we get issued
+	u, err := url.JoinPath("http://"+serviceUrl, aliceDid.String(), clientDid.String())
+	if err != nil {
+		return err
+	}
+
+	req, err := http.NewRequest(http.MethodGet, u, nil)
+	if err != nil {
+		return err
+	}
+
+	err = bearer.AddBearerContainerCompressed(req.Header, proofs)
+	if err != nil {
+		return err
+	}
+
+	res, err := http.DefaultClient.Do(req.WithContext(ctx))
+	if err != nil {
+		return err
+	}
+
+	defer res.Body.Close()
+	if res.StatusCode != http.StatusOK {
+		body, err := io.ReadAll(res.Body)
+		if err != nil {
+			return fmt.Errorf("unexpected status code: %d, error reading body: %w", res.StatusCode, err)
+		}
+		return fmt.Errorf("unexpected status code: %d, body: %v", res.StatusCode, string(body))
+	}
+
+	log.Printf("response status code: %d", res.StatusCode)
+
+	return nil
+}