1 files changed, 92 insertions, 0 deletions
diff --git a/pkg/hooks/1.0.0/when.go b/pkg/hooks/1.0.0/when.go
new file mode 100644
index 000000000..3d2a5fd72
--- /dev/null
+++ b/pkg/hooks/1.0.0/when.go
@@ -0,0 +1,92 @@
+package hook
+
+import (
+	"regexp"
+
+	rspec "github.com/opencontainers/runtime-spec/specs-go"
+	"github.com/pkg/errors"
+)
+
+// When holds hook-injection conditions.
+type When struct {
+	Always        *bool             `json:"always,omitempty"`
+	Annotations   map[string]string `json:"annotation,omitempty"`
+	Commands      []string          `json:"commands,omitempty"`
+	HasBindMounts *bool             `json:"hasBindMounts,omitempty"`
+
+	// Or enables any-of matching.
+	//
+	// Deprecated: this property is for is backwards-compatibility with
+	// 0.1.0 hooks.  It will be removed when we drop support for them.
+	Or bool `json:"-"`
+}
+
+// Match returns true if the given conditions match the configuration.
+func (when *When) Match(config *rspec.Spec, annotations map[string]string, hasBindMounts bool) (match bool, err error) {
+	matches := 0
+
+	if when.Always != nil {
+		if *when.Always {
+			if when.Or {
+				return true, nil
+			}
+			matches++
+		} else if !when.Or {
+			return false, nil
+		}
+	}
+
+	if when.HasBindMounts != nil {
+		if *when.HasBindMounts && hasBindMounts {
+			if when.Or {
+				return true, nil
+			}
+			matches++
+		} else if !when.Or {
+			return false, nil
+		}
+	}
+
+	for keyPattern, valuePattern := range when.Annotations {
+		match := false
+		for key, value := range annotations {
+			match, err = regexp.MatchString(keyPattern, key)
+			if err != nil {
+				return false, errors.Wrap(err, "annotation key")
+			}
+			if match {
+				match, err = regexp.MatchString(valuePattern, value)
+				if err != nil {
+					return false, errors.Wrap(err, "annotation value")
+				}
+				if match {
+					break
+				}
+			}
+		}
+		if match {
+			if when.Or {
+				return true, nil
+			}
+			matches++
+		} else if !when.Or {
+			return false, nil
+		}
+	}
+
+	if config.Process != nil {
+		command := config.Process.Args[0]
+		for _, cmdPattern := range when.Commands {
+			match, err := regexp.MatchString(cmdPattern, command)
+			if err != nil {
+				return false, errors.Wrap(err, "command")
+			}
+			if match {
+				return true, nil
+			}
+		}
+		return false, nil
+	}
+
+	return matches > 0, nil
+}