feat(constraints): add compound constraints and olm.constraint value …

…parser

Signed-off-by: Eric Stroczynski <ericstroczynski@gmail.com>

pkg/constraints/cel.go

@@ -16,17 +16,6 @@ import (
 // PropertiesKey is the key for bundle properties map (input data for CEL evaluation)
 const PropertiesKey = "properties"
 
-// Constraint is a struct representing the new generic constraint type
-type Constraint struct {
- // Constraint message that surfaces in resolution
- // This field is optional
- Message string `json:"message" yaml:"message"`
-
- // The cel struct that contraints CEL expression
- // This field is required
- Cel *Cel `json:"cel" yaml:"cel"`
-}
-
 // Cel is a struct representing CEL expression information
 type Cel struct {
  // The CEL expression

pkg/constraints/constraint.go

@@ -0,0 +1,83 @@
+package constraints
+
+import (
+ "bytes"
+ "encoding/json"
+ "fmt"
+)
+
+// OLMConstraintType is the schema "type" key for all constraints known to OLM
+// (except for legacy types).
+const OLMConstraintType = "olm.constraint"
+
+// Constraint holds parsed, potentially nested dependency constraints.
+type Constraint struct {
+ // Constraint message that surfaces in resolution
+ // This field is optional
+ Message string `json:"message"`
+
+ // The cel struct that contraints CEL expression
+ Cel *Cel `json:"cel,omitempty" yaml:"cel,omitempty"`
+
+ // Package defines a constraint for a package within a version range.
+ Package *PackageConstraint `json:"package,omitempty" yaml:"package,omitempty"`
+ // GVK defines a constraint for a GVK.
+ GVK *GVKConstraint `json:"gvk,omitempty" yaml:"gvk,omitempty"`
+
+ // All, Any, and None are compound constraints. See this enhancement for details:
+ // https://github.com/operator-framework/enhancements/blob/master/enhancements/compound-bundle-constraints.md
+ All *CompoundConstraint `json:"all,omitempty" yaml:"all,omitempty"`
+ Any *CompoundConstraint `json:"any,omitempty" yaml:"any,omitempty"`
+ // A note on None: this constraint is not particularly useful by itself.
+ // It should be used within an All constraint alongside some other constraint type
+ // since saying "none of these GVKs/packages/etc." without an alternative doesn't make sense.
+ None *CompoundConstraint `json:"none,omitempty" yaml:"none,omitempty"`
+}
+
+// CompoundConstraint holds a list of potentially nested constraints
+// over which a boolean operation is applied.
+type CompoundConstraint struct {
+ Constraints []Constraint `json:"constraints"`
+}
+
+// GVKConstraint defines a GVK constraint.
+type GVKConstraint struct {
+ Group string `json:"group"`
+ Kind string `json:"kind"`
+ Version string `json:"version"`
+}
+
+// PackageConstraint defines a package constraint.
+type PackageConstraint struct {
+ // Name of the package.
+ Name string `json:"name"`
+ // VersionRange required for the package.
+ VersionRange string `json:"versionRange"`
+}
+
+// maxConstraintSize defines the maximum raw size in bytes of an olm.constraint.
+// 64Kb seems reasonable, since this number allows for long description strings
+// and either few deep nestings or shallow nestings and long constraints lists,
+// but not both.
+const maxConstraintSize = 2 << 16
+
+// ErrMaxConstraintSizeExceeded is returned when a constraint's size > maxConstraintSize.
+var ErrMaxConstraintSizeExceeded = fmt.Errorf("olm.constraint value is greater than max constraint size %d bytes", maxConstraintSize)
+
+// Parse parses an olm.constraint property's value recursively into a Constraint.
+// Unknown value schemas result in an error. A too-large value results in an error.
+func Parse(v json.RawMessage) (c Constraint, err error) {
+ // There is no way to explicitly limit nesting depth.
+ // From https://github.com/golang/go/issues/31789#issuecomment-538134396,
+ // the recommended approach is to error out if raw input size
+ // is greater than some threshold.
+ if len(v) > maxConstraintSize {
+ return c, ErrMaxConstraintSizeExceeded
+ }
+
+ d := json.NewDecoder(bytes.NewBuffer(v))
+ d.DisallowUnknownFields()
+ err = d.Decode(&c)
+
+ return
+}

pkg/constraints/constraint_test.go

@@ -0,0 +1,274 @@
+package constraints
+
+import (
+ "encoding/json"
+ "fmt"
+ "math/rand"
+ "testing"
+
+ "github.com/stretchr/testify/require"
+)
+
+func TestParse(t *testing.T) {
+ type spec struct {
+ name string
+ input json.RawMessage
+ expConstraint Constraint
+ expError string
+ }
+
+ specs := []spec{
+ {
+ name: "Valid/BasicGVK",
+ input: json.RawMessage(inputBasicGVK),
+ expConstraint: Constraint{
+ Message: "blah",
+ GVK: &GVKConstraint{Group: "example.com", Version: "v1", Kind: "Foo"},
+ },
+ },
+ {
+ name: "Valid/BasicPackage",
+ input: json.RawMessage(inputBasicPackage),
+ expConstraint: Constraint{
+ Message: "blah",
+ Package: &PackageConstraint{Name: "foo", VersionRange: ">=1.0.0"},
+ },
+ },
+ {
+ name: "Valid/BasicAll",
+ input: json.RawMessage(fmt.Sprintf(inputBasicCompoundTmpl, "all")),
+ expConstraint: Constraint{
+ Message: "blah",
+ All: &CompoundConstraint{
+ Constraints: []Constraint{
+ {
+ Message: "blah blah",
+ Package: &PackageConstraint{Name: "fuz", VersionRange: ">=1.0.0"},
+ },
+ },
+ },
+ },
+ },
+ {
+ name: "Valid/BasicAny",
+ input: json.RawMessage(fmt.Sprintf(inputBasicCompoundTmpl, "any")),
+ expConstraint: Constraint{
+ Message: "blah",
+ Any: &CompoundConstraint{
+ Constraints: []Constraint{
+ {
+ Message: "blah blah",
+ Package: &PackageConstraint{Name: "fuz", VersionRange: ">=1.0.0"},
+ },
+ },
+ },
+ },
+ },
+ {
+ name: "Valid/BasicNone",
+ input: json.RawMessage(fmt.Sprintf(inputBasicCompoundTmpl, "none")),
+ expConstraint: Constraint{
+ Message: "blah",
+ None: &CompoundConstraint{
+ Constraints: []Constraint{
+ {
+ Message: "blah blah",
+ Package: &PackageConstraint{Name: "fuz", VersionRange: ">=1.0.0"},
+ },
+ },
+ },
+ },
+ },
+ {
+ name: "Valid/Complex",
+ input: json.RawMessage(inputComplex),
+ expConstraint: Constraint{
+ Message: "blah",
+ All: &CompoundConstraint{
+ Constraints: []Constraint{
+ {Package: &PackageConstraint{Name: "fuz", VersionRange: ">=1.0.0"}},
+ {GVK: &GVKConstraint{Group: "fals.example.com", Kind: "Fal", Version: "v1"}},
+ {
+ Message: "foo and buf must be stable versions",
+ All: &CompoundConstraint{
+ Constraints: []Constraint{
+ {Package: &PackageConstraint{Name: "foo", VersionRange: ">=1.0.0"}},
+ {Package: &PackageConstraint{Name: "buf", VersionRange: ">=1.0.0"}},
+ {GVK: &GVKConstraint{Group: "foos.example.com", Kind: "Foo", Version: "v1"}},
+ },
+ },
+ },
+ {
+ Message: "blah blah",
+ Any: &CompoundConstraint{
+ Constraints: []Constraint{
+ {GVK: &GVKConstraint{Group: "foos.example.com", Kind: "Foo", Version: "v1beta1"}},
+ {GVK: &GVKConstraint{Group: "foos.example.com", Kind: "Foo", Version: "v1beta2"}},
+ {GVK: &GVKConstraint{Group: "foos.example.com", Kind: "Foo", Version: "v1"}},
+ },
+ },
+ },
+ {
+ None: &CompoundConstraint{
+ Constraints: []Constraint{
+ {GVK: &GVKConstraint{Group: "bazs.example.com", Kind: "Baz", Version: "v1alpha1"}},
+ },
+ },
+ },
+ },
+ },
+ },
+ },
+ {
+ name: "Invalid/TooLarge",
+ input: func(t *testing.T) json.RawMessage {
+ p := make([]byte, maxConstraintSize+1)
+ _, err := rand.Read(p)
+ require.NoError(t, err)
+ return json.RawMessage(p)
+ }(t),
+ expError: ErrMaxConstraintSizeExceeded.Error(),
+ },
+ {
+ name: "Invalid/UnknownField",
+ input: json.RawMessage(
+ `{"message": "something", "arbitrary": {"key": "value"}}`,
+ ),
+ expError: `json: unknown field "arbitrary"`,
+ },
+ }
+
+ for _, s := range specs {
+ t.Run(s.name, func(t *testing.T) {
+ constraint, err := Parse(s.input)
+ if s.expError == "" {
+ require.NoError(t, err)
+ require.Equal(t, s.expConstraint, constraint)
+ } else {
+ require.EqualError(t, err, s.expError)
+ }
+ })
+ }
+}
+
+const (
+ inputBasicGVK = `{
+ "message": "blah",
+ "gvk": {
+ "group": "example.com",
+ "version": "v1",
+ "kind": "Foo"
+ }
+ }`
+
+ inputBasicPackage = `{
+ "message": "blah",
+ "package": {
+ "name": "foo",
+ "versionRange": ">=1.0.0"
+ }
+ }`
+
+ inputBasicCompoundTmpl = `{
+"message": "blah",
+"%s": {
+ "constraints": [
+ {
+ "message": "blah blah",
+ "package": {
+ "name": "fuz",
+ "versionRange": ">=1.0.0"
+ }
+ }
+ ]
+}}
+`
+
+ inputComplex = `{
+"message": "blah",
+"all": {
+ "constraints": [
+ {
+ "package": {
+ "name": "fuz",
+ "versionRange": ">=1.0.0"
+ }
+ },
+ {
+ "gvk": {
+ "group": "fals.example.com",
+ "version": "v1",
+ "kind": "Fal"
+ }
+ },
+ {
+ "message": "foo and buf must be stable versions",
+ "all": {
+ "constraints": [
+ {
+ "package": {
+ "name": "foo",
+ "versionRange": ">=1.0.0"
+ }
+ },
+ {
+ "package": {
+ "name": "buf",
+ "versionRange": ">=1.0.0"
+ }
+ },
+ {
+ "gvk": {
+ "group": "foos.example.com",
+ "version": "v1",
+ "kind": "Foo"
+ }
+ }
+ ]
+ }
+ },
+ {
+ "message": "blah blah",
+ "any": {
+ "constraints": [
+ {
+ "gvk": {
+ "group": "foos.example.com",
+ "version": "v1beta1",
+ "kind": "Foo"
+ }
+ },
+ {
+ "gvk": {
+ "group": "foos.example.com",
+ "version": "v1beta2",
+ "kind": "Foo"
+ }
+ },
+ {
+ "gvk": {
+ "group": "foos.example.com",
+ "version": "v1",
+ "kind": "Foo"
+ }
+ }
+ ]
+ }
+ },
+ {
+ "none": {
+ "constraints": [
+ {
+ "gvk": {
+ "group": "bazs.example.com",
+ "version": "v1alpha1",
+ "kind": "Baz"
+ }
+ }
+ ]
+ }
+ }
+ ]
+}}
+`
+)