feat: skip saving legacy version when running scrapper

This change will enable the use of legacy APIs using a default
version 2021-01-01 (which predates vervet) without vervet-underground
scraping for the OpenAPI contract. This enables vervet to be used on
legacy APIs which do not meet the OpenAPI standard.

.gitignore

@@ -8,5 +8,6 @@
 
 **/server
 config.json
+config.local.json
 config.*.test.json
 result

vervet-underground/internal/scraper/scraper.go

@@ -155,6 +155,12 @@ func (s *Scraper) scrape(ctx context.Context, scrapeTime time.Time, svc service)
 	for i := range versions {
 		// TODO: we might run this concurrently per live service pod if/when
 		// we're more k8s aware, but we won't do that yet.
+
+		// Skip if it's a legacy api using the default legacy version.
+		if isLegacyVersion(versions[i]) {
+			continue
+		}
+
 		contents, isNew, err := s.getNewVersion(ctx, svc, versions[i])
 		if err != nil {
 			return errors.WithStack(err)
@@ -275,6 +281,12 @@ func (s *Scraper) hasNewVersion(ctx context.Context, svc service, version string
 	return s.storage.HasVersion(ctx, svc.name, version, digest)
 }
 
+// isLegacyVersion is used to identify legacy APIs which should be excluded.
+func isLegacyVersion(version string) bool {
+	// This default version predates vervet's creation date.
+	return version == "2021-01-01"
+}
+
 func (s *Scraper) Versions() vervet.VersionSlice {
 	return s.storage.Versions()
 }

vervet-underground/internal/scraper/scraper_test.go

@@ -39,8 +39,9 @@ var (
 		},
 	}
 	animals = &testService{
-		versions: []string{"2021-10-01", "2021-10-16"},
+		versions: []string{"2021-01-01", "2021-10-01", "2021-10-16"},
 		contents: map[string]string{
+			"2021-01-01": `{"paths":{"/legacy": {}}}`,
 			"2021-10-01": `{"paths":{"/geckos": {}}}`,
 			"2021-10-16": `{"paths":{"/geckos": {}, "/puppies": {}}}`,
 		},
@@ -136,6 +137,43 @@ func TestScraper(t *testing.T) {
 	}
 }
 
+func TestScraperWithLegacy(t *testing.T) {
+	c := qt.New(t)
+
+	_, animalsService := setupHttpServers(c)
+	tests := []struct {
+		name, version, digest string
+	}{
+		{"animals", "2021-01-01", "sha256:XX2f9c3iySLCw54rJ/CZs+ZK6IQy7GXNY4nSOyu2QG4="},
+	}
+
+	cfg := &config.ServerConfig{
+		Services: []config.ServiceConfig{
+			{
+				Name: "animals", URL: animalsService.URL,
+			},
+		},
+	}
+	st := mem.New()
+	sc, err := scraper.New(cfg, st, scraper.Clock(func() time.Time { return t0 }))
+	c.Assert(err, qt.IsNil)
+
+	// Cancel the scrape context after a timeout so we don't hang the test
+	ctx, cancel := context.WithTimeout(context.Background(), time.Second*60)
+	c.Cleanup(cancel)
+
+	// Run the scrape
+	err = sc.Run(ctx)
+	c.Assert(err, qt.IsNil)
+
+	// Legacy (default) version should not be stored
+	for _, test := range tests {
+		ok, err := st.HasVersion(ctx, test.name, test.version, test.digest)
+		c.Assert(err, qt.IsNil)
+		c.Assert(ok, qt.IsFalse)
+	}
+}
+
 func TestEmptyScrape(t *testing.T) {
 	c := qt.New(t)
 	cfg := &config.ServerConfig{