refactor! remove pkg directory (#145)

* refactor!: remove pkg directory

* chore: include breaking changes in draft

example_verify_test.go

@@ -0,0 +1,54 @@
+package attest_test
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"github.com/docker/attest"
+	"github.com/docker/attest/oci"
+	"github.com/docker/attest/policy"
+	"github.com/docker/attest/tuf"
+)
+
+func ExampleVerify_remote() {
+	// create a tuf client
+	home, err := os.UserHomeDir()
+	if err != nil {
+		panic(err)
+	}
+	tufOutputPath := filepath.Join(home, ".docker", "tuf")
+	tufClientOpts := tuf.NewDockerDefaultClientOptions(tufOutputPath)
+
+	// create a resolver for remote attestations
+	image := "registry-1.docker.io/library/notary:server"
+	platform := "linux/amd64"
+
+	// configure policy options
+	opts := &policy.Options{
+		TUFClientOptions: tufClientOpts,
+		LocalTargetsDir:  filepath.Join(home, ".docker", "policy"), // location to store policy files downloaded from TUF
+		LocalPolicyDir:   "",                                       // overrides TUF policy for local policy files if set
+		PolicyID:         "",                                       // set to ignore policy mapping and select a policy by id
+		DisableTUF:       false,                                    // set to disable TUF and rely on local policy files
+	}
+
+	src, err := oci.ParseImageSpec(image, oci.WithPlatform(platform))
+	if err != nil {
+		panic(err)
+	}
+	// verify attestations
+	result, err := attest.Verify(context.Background(), src, opts)
+	if err != nil {
+		panic(err)
+	}
+	switch result.Outcome {
+	case attest.OutcomeSuccess:
+		fmt.Println("policy passed")
+	case attest.OutcomeNoPolicy:
+		fmt.Println("no policy for image")
+	case attest.OutcomeFailure:
+		fmt.Println("policy failed")
+	}
+}