Detect replacement circuits while adding package channels

pkg/sqlite/configmap_test.go

@@ -1,8 +1,11 @@
 package sqlite
 
 import (
+	"bytes"
 	"context"
+	"io/ioutil"
 	"os"
+	"strings"
 	"testing"
 
 	"github.com/sirupsen/logrus"
@@ -33,6 +36,33 @@ func TestConfigMapLoader(t *testing.T) {
 	require.NoError(t, loader.Populate())
 }
 
+func TestReplaceCircuit(t *testing.T) {
+	logrus.SetLevel(logrus.DebugLevel)
+
+	store, err := NewSQLLiteLoader("test.db")
+	require.NoError(t, err)
+	defer os.Remove("test.db")
+
+	path := "../../configmap.example.yaml"
+	cmap, err := ioutil.ReadFile(path)
+
+	require.NoError(t, err, "unable to load configmap from file %s", path)
+
+	// Make etcdoperator.v0.9.0 in the example replace 0.9.2 to create a loop
+	sReader := strings.NewReader(string(bytes.Replace(cmap,
+			[]byte("replaces: etcdoperator.v0.6.1"),
+			[]byte("replaces: etcdoperator.v0.9.2"), 1)))
+
+	decoder := yaml.NewYAMLOrJSONDecoder(sReader, 30)
+	manifest := v1.ConfigMap{}
+	err = decoder.Decode(&manifest)
+	require.NoError(t, err, "could not decode contents of file %s into configmap", path)
+
+	loader := NewSQLLoaderForConfigMap(store, manifest)
+	err = loader.Populate()
+	require.Error(t, err, "Circuit detected, etcdoperator.v0.9.0 replaces etcdoperator.v0.9.2")
+}
+
 func TestQuerierForConfigmap(t *testing.T) {
 	load, err := NewSQLLiteLoader("test.db")
 	require.NoError(t, err)

pkg/sqlite/load.go

@@ -187,8 +187,10 @@ func (s *SQLLoader) AddPackageChannels(manifest registry.PackageManifest) error
 
 		channelEntryCSVName := c.CurrentCSVName
 		depth := 1
-		for {
 
+		// Since this loop depends on following 'replaces', keep track of where it's been
+		replaceCircuit := map[string]bool{channelEntryCSVName: true}
+		for {
 			// Get CSV for current entry
 			channelEntryCSV, err := s.getCSV(tx, channelEntryCSVName)
 			if err != nil {
@@ -254,6 +256,12 @@ func (s *SQLLoader) AddPackageChannels(manifest registry.PackageManifest) error
 				return fmt.Errorf("%s specifies replacement that couldn't be found", c.CurrentCSVName)
 			}
 
+			// If we find 'replaces' in the circuit list then we've seen it already, break out
+			if _, ok := replaceCircuit[replaces]; ok {
+			   return fmt.Errorf("Circuit detected, %s replaces %s", channelEntryCSVName, replaces)
+			}
+			replaceCircuit[channelEntryCSVName] = true
+
 			replacedChannelEntry, err := addChannelEntry.Exec(c.Name, manifest.PackageName, replaced.GetName(), depth)
 			if err != nil {
 				return err