api: rename /api/versions to versionsapi and /api/attestationcfig to attestationconfigapi (#1876)

* rename to attestationconfigapi + put client and fetcher inside pkg

* rename api/version to versionsapi and put fetcher + client inside pkg

* rename AttestationConfigAPIFetcher to Fetcher

internal/api/versionsapi/fetcher_test.go

@@ -0,0 +1,217 @@
+/*
+Copyright (c) Edgeless Systems GmbH
+
+SPDX-License-Identifier: AGPL-3.0-only
+*/
+
+package versionsapi
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"io"
+	"net/http"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"go.uber.org/goleak"
+)
+
+func TestMain(m *testing.M) {
+	goleak.VerifyTestMain(m)
+}
+
+func TestFetchVersionList(t *testing.T) {
+	require := require.New(t)
+
+	majorList := func() *List {
+		return &List{
+			Ref:         "test-ref",
+			Stream:      "nightly",
+			Granularity: GranularityMajor,
+			Base:        "v1",
+			Kind:        VersionKindImage,
+			Versions:    []string{"v1.0", "v1.1", "v1.2"},
+		}
+	}
+	minorList := func() *List {
+		return &List{
+			Ref:         "test-ref",
+			Stream:      "nightly",
+			Granularity: GranularityMinor,
+			Base:        "v1.1",
+			Kind:        VersionKindImage,
+			Versions:    []string{"v1.1.0", "v1.1.1", "v1.1.2"},
+		}
+	}
+	majorListJSON, err := json.Marshal(majorList())
+	require.NoError(err)
+	minorListJSON, err := json.Marshal(minorList())
+	require.NoError(err)
+	inconsistentList := majorList()
+	inconsistentList.Base = "v2"
+	inconsistentListJSON, err := json.Marshal(inconsistentList)
+	require.NoError(err)
+
+	testCases := map[string]struct {
+		list       List
+		serverPath string
+		serverResp *http.Response
+		wantList   List
+		wantErr    bool
+	}{
+		"major list fetched": {
+			list: List{
+				Ref:         "test-ref",
+				Stream:      "nightly",
+				Granularity: GranularityMajor,
+				Base:        "v1",
+				Kind:        VersionKindImage,
+			},
+			serverPath: "/constellation/v1/ref/test-ref/stream/nightly/versions/major/v1/image.json",
+			serverResp: &http.Response{
+				StatusCode: http.StatusOK,
+				Body:       io.NopCloser(bytes.NewBuffer(majorListJSON)),
+			},
+			wantList: *majorList(),
+		},
+		"minor list fetched": {
+			list: List{
+				Ref:         "test-ref",
+				Stream:      "nightly",
+				Granularity: GranularityMinor,
+				Base:        "v1.1",
+				Kind:        VersionKindImage,
+			},
+			serverPath: "/constellation/v1/ref/test-ref/stream/nightly/versions/minor/v1.1/image.json",
+			serverResp: &http.Response{
+				StatusCode: http.StatusOK,
+				Body:       io.NopCloser(bytes.NewBuffer(minorListJSON)),
+			},
+			wantList: *minorList(),
+		},
+		"list does not exist": {
+			list: List{
+				Ref:         "another-ref",
+				Stream:      "nightly",
+				Granularity: GranularityMajor,
+				Base:        "v1",
+				Kind:        VersionKindImage,
+			},
+			wantErr: true,
+		},
+		"invalid list requested": {
+			list: List{
+				Ref:         "",
+				Stream:      "unknown",
+				Granularity: GranularityMajor,
+				Base:        "v1",
+				Kind:        VersionKindImage,
+			},
+			wantErr: true,
+		},
+		"unexpected error code": {
+			list: List{
+				Ref:         "test-ref",
+				Stream:      "nightly",
+				Granularity: GranularityMajor,
+				Base:        "v1",
+				Kind:        VersionKindImage,
+			},
+			serverPath: "/constellation/v1/ref/test-ref/stream/nightly/versions/major/v1/image.json",
+			serverResp: &http.Response{
+				StatusCode: http.StatusInternalServerError,
+				Body:       io.NopCloser(bytes.NewBufferString("Internal Server Error")),
+			},
+			wantErr: true,
+		},
+		"invalid json returned": {
+			list: List{
+				Ref:         "test-ref",
+				Stream:      "nightly",
+				Granularity: GranularityMajor,
+				Base:        "v1",
+				Kind:        VersionKindImage,
+			},
+			serverPath: "/constellation/v1/ref/test-ref/stream/nightly/versions/major/v1/image.json",
+			serverResp: &http.Response{
+				StatusCode: http.StatusOK,
+				Body:       io.NopCloser(bytes.NewBufferString("invalid json")),
+			},
+			wantErr: true,
+		},
+		"invalid list returned": {
+			list: List{
+				Ref:         "test-ref",
+				Stream:      "nightly",
+				Granularity: GranularityMajor,
+				Base:        "v2",
+				Kind:        VersionKindImage,
+			},
+			serverPath: "/constellation/v1/ref/test-ref/stream/nightly/versions/major/v2/image.json",
+			serverResp: &http.Response{
+				StatusCode: http.StatusOK,
+				Body:       io.NopCloser(bytes.NewBuffer(inconsistentListJSON)),
+			},
+			wantErr: true,
+		},
+		// TODO(katexochen): Remove or find strategy to implement this check in a generic way
+		// "response does not match request": {
+		// 	list: List{
+		// 		Ref:         "test-ref",
+		// 		Stream:      "nightly",
+		// 		Granularity: GranularityMajor,
+		// 		Base:        "v3",
+		// 		Kind:        VersionKindImage,
+		// 	},
+		// 	serverPath: "/constellation/v1/ref/test-ref/stream/nightly/versions/major/v3/image.json",
+		// 	serverResp: &http.Response{
+		// 		StatusCode: http.StatusOK,
+		// 		Body:       io.NopCloser(bytes.NewBuffer(minorListJSON)),
+		// 	},
+		// 	wantErr: true,
+		// },
+	}
+
+	for name, tc := range testCases {
+		t.Run(name, func(t *testing.T) {
+			assert := assert.New(t)
+
+			client := newTestClient(func(req *http.Request) *http.Response {
+				if req.URL.Path != tc.serverPath {
+					return &http.Response{
+						StatusCode: http.StatusNotFound,
+						Body:       io.NopCloser(bytes.NewBufferString("Not found.")),
+					}
+				}
+				return tc.serverResp
+			})
+
+			fetcher := Fetcher{client}
+
+			list, err := fetcher.FetchVersionList(context.Background(), tc.list)
+
+			if tc.wantErr {
+				assert.Error(err)
+				return
+			}
+			assert.NoError(err)
+			assert.Equal(tc.wantList, list)
+		})
+	}
+}
+
+type roundTripFunc func(req *http.Request) *http.Response
+
+func (f roundTripFunc) RoundTrip(req *http.Request) (*http.Response, error) {
+	return f(req), nil
+}
+
+// newTestClient returns *http.Client with Transport replaced to avoid making real calls.
+func newTestClient(fn roundTripFunc) *http.Client {
+	return &http.Client{
+		Transport: fn,
+	}
+}