1 files changed, 83 insertions, 0 deletions
diff --git a/pkg/hooks/read.go b/pkg/hooks/read.go
new file mode 100644
index 000000000..fab37351b
--- /dev/null
+++ b/pkg/hooks/read.go
@@ -0,0 +1,83 @@
+// Package hooks implements CRI-O's hook handling.
+package hooks
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"path/filepath"
+	"strings"
+
+	"github.com/pkg/errors"
+	current "github.com/projectatomic/libpod/pkg/hooks/1.0.0"
+)
+
+type reader func(content []byte) (*current.Hook, error)
+
+var (
+	// ErrNoJSONSuffix represents hook-add attempts where the filename
+	// does not end in '.json'.
+	ErrNoJSONSuffix = errors.New("hook filename does not end in '.json'")
+
+	// Readers registers per-version hook readers.
+	Readers = map[string]reader{}
+)
+
+// Read reads a hook JSON file, verifies it, and returns the hook configuration.
+func Read(path string) (*current.Hook, error) {
+	if !strings.HasSuffix(path, ".json") {
+		return nil, ErrNoJSONSuffix
+	}
+	content, err := ioutil.ReadFile(path)
+	if err != nil {
+		return nil, err
+	}
+	hook, err := read(content)
+	if err != nil {
+		return nil, errors.Wrapf(err, "parsing hook %q", path)
+	}
+	err = hook.Validate()
+	return hook, err
+}
+
+func read(content []byte) (hook *current.Hook, err error) {
+	var ver version
+	if err := json.Unmarshal(content, &ver); err != nil {
+		return nil, errors.Wrap(err, "version check")
+	}
+	reader, ok := Readers[ver.Version]
+	if !ok {
+		return nil, fmt.Errorf("unrecognized hook version: %q", ver.Version)
+	}
+
+	hook, err = reader(content)
+	if err != nil {
+		return hook, errors.Wrap(err, ver.Version)
+	}
+	return hook, err
+}
+
+// ReadDir reads hook JSON files from a directory into the given map,
+// clobbering any previous entries with the same filenames.
+func ReadDir(path string, hooks map[string]*current.Hook) error {
+	files, err := ioutil.ReadDir(path)
+	if err != nil {
+		return err
+	}
+
+	for _, file := range files {
+		hook, err := Read(filepath.Join(path, file.Name()))
+		if err != nil {
+			if err == ErrNoJSONSuffix {
+				continue
+			}
+			return err
+		}
+		hooks[file.Name()] = hook
+	}
+	return nil
+}
+
+func init() {
+	Readers[current.Version] = current.Read
+}