feat(resolver): Indicate dependency class in resolution constraint text

This commit introduces a String() method to the Predicate interface, implementations
of which are used to build clauses that are fed to the sat solver. Calling the
predicate.String() method enhances the error messages displayed when dependency
resolution fails.

For example, an error message previously due to an unsatisfyiable contraint was
diplayed as

```
ResolutionFailed' constraints not satisfiable: bundle etcdoperator-community.v0.6.1 has
a dependency without any candidates to satisfy it, subscription etcd requires
my-catalog/olm/alpha/etcdoperator-community.v0.6.1, subscription etcd exists
```

With this commit, the same error is displayed as:

```
ResolutionFailed' constraints not satisfiable: bundle etcdoperator-community.v0.6.1 requires
an operator with package:foo and with version in range:>0.27.0, subscription etcd requires
my-catalog/olm/alpha/etcdoperator-community.v0.6.1, subscription etcd exists
```

Signed-off-by: Anik Bhattacharjee <[email protected]>

Author: anik120

pkg/controller/registry/resolver/cache_test.go

@@ -123,7 +123,7 @@ func TestOperatorCacheConcurrency(t *testing.T) {
 			nc := c.Namespaced(namespaces...)
 			for _, index := range indices {
 				name := fmt.Sprintf("%s/%s", keys[index].Namespace, keys[index].Name)
-				operators := nc.Find(WithCSVName(name))
+				operators := nc.Find(CSVNamePredicate(name))
 				if len(operators) != 1 {
 					return fmt.Errorf("expected 1 operator, got %d", len(operators))
 				}
@@ -159,7 +159,7 @@ func TestOperatorCacheExpiration(t *testing.T) {
 	c := NewOperatorCache(rcp, logrus.New(), catsrcLister)
 	c.ttl = 0 // instantly stale
 
-	require.Len(t, c.Namespaced("dummynamespace").Catalog(key).Find(WithCSVName("csvname")), 1)
+	require.Len(t, c.Namespaced("dummynamespace").Catalog(key).Find(CSVNamePredicate("csvname")), 1)
 }
 
 func TestOperatorCacheReuse(t *testing.T) {
@@ -182,7 +182,7 @@ func TestOperatorCacheReuse(t *testing.T) {
 
 	c := NewOperatorCache(rcp, logrus.New(), catsrcLister)
 
-	require.Len(t, c.Namespaced("dummynamespace").Catalog(key).Find(WithCSVName("csvname")), 1)
+	require.Len(t, c.Namespaced("dummynamespace").Catalog(key).Find(CSVNamePredicate("csvname")), 1)
 }
 
 func TestCatalogSnapshotExpired(t *testing.T) {
@@ -232,7 +232,7 @@ func TestCatalogSnapshotFind(t *testing.T) {
 	for _, tt := range []tc{
 		{
 			Name: "nothing satisfies predicate",
-			Predicate: OperatorPredicateFunc(func(*Operator) bool {
+			Predicate: OperatorPredicateTestFunc(func(*Operator) bool {
 				return false
 			}),
 			Operators: []*Operator{
@@ -244,15 +244,15 @@ func TestCatalogSnapshotFind(t *testing.T) {
 		},
 		{
 			Name: "no operators in snapshot",
-			Predicate: OperatorPredicateFunc(func(*Operator) bool {
+			Predicate: OperatorPredicateTestFunc(func(*Operator) bool {
 				return true
 			}),
 			Operators: nil,
 			Expected:  nil,
 		},
 		{
 			Name: "everything satisfies predicate",
-			Predicate: OperatorPredicateFunc(func(*Operator) bool {
+			Predicate: OperatorPredicateTestFunc(func(*Operator) bool {
 				return true
 			}),
 			Operators: []*Operator{
@@ -268,7 +268,7 @@ func TestCatalogSnapshotFind(t *testing.T) {
 		},
 		{
 			Name: "some satisfy predicate",
-			Predicate: OperatorPredicateFunc(func(o *Operator) bool {
+			Predicate: OperatorPredicateTestFunc(func(o *Operator) bool {
 				return o.name != "a"
 			}),
 			Operators: []*Operator{
@@ -333,7 +333,7 @@ func TestStripPluralRequiredAndProvidedAPIKeys(t *testing.T) {
 	c := NewOperatorCache(rcp, logrus.New(), catsrcLister)
 
 	nc := c.Namespaced("testnamespace")
-	result, err := AtLeast(1, nc.Find(ProvidingAPI(opregistry.APIKey{Group: "g", Version: "v1", Kind: "K"})))
+	result, err := AtLeast(1, nc.Find(ProvidingAPIPredicate(opregistry.APIKey{Group: "g", Version: "v1", Kind: "K"})))
 	assert.NoError(t, err)
 	assert.Equal(t, 1, len(result))
 	assert.Equal(t, "K.v1.g", result[0].providedAPIs.String())

pkg/controller/registry/resolver/installabletypes.go

@@ -32,8 +32,8 @@ func (i *BundleInstallable) AddConflict(id solver.Identifier) {
 	i.constraints = append(i.constraints, solver.Conflict(id))
 }
 
-func (i *BundleInstallable) AddDependency(dependencies []solver.Identifier) {
-	i.constraints = append(i.constraints, solver.Dependency(dependencies...))
+func (i *BundleInstallable) AddConstraint(c solver.Constraint) {
+	i.constraints = append(i.constraints, c)
 }
 
 func (i *BundleInstallable) BundleSourceInfo() (string, string, registry.CatalogKey, error) {

pkg/controller/registry/resolver/operators.go

@@ -361,6 +361,10 @@ func NewOperatorFromV1Alpha1CSV(csv *v1alpha1.ClusterServiceVersion) (*Operator,
 	}, nil
 }
 
+func (o *Operator) Name() string {
+	return o.name
+}
+
 func (o *Operator) ProvidedAPIs() APISet {
 	return o.providedAPIs
 }
@@ -411,6 +415,10 @@ func (o *Operator) Version() *semver.Version {
 	return o.version
 }
 
+func (o *Operator) SemverRange() (semver.Range, error) {
+	return semver.ParseRange(o.Bundle().SkipRange)
+}
+
 func (o *Operator) Inline() bool {
 	return o.bundle != nil && o.bundle.GetBundlePath() == ""
 }