hooks: Add package support for extension stages

We aren't consuming this yet, but these pkg/hooks changes lay the
groundwork for future libpod changes to support post-exit hooks [1,2].

[1]: https://github.com/projectatomic/libpod/issues/730
[2]: https://github.com/opencontainers/runc/issues/1797

Signed-off-by: W. Trevor King <wking@tremily.us>

Closes: #758
Approved by: rhatdan

2 files changed, 29 insertions, 11 deletions

diff --git a/pkg/hooks/1.0.0/hook.go b/pkg/hooks/1.0.0/hook.go
index cf623ee42..77fbab5aa 100644
--- a/pkg/hooks/1.0.0/hook.go
+++ b/pkg/hooks/1.0.0/hook.go
@@ -31,7 +31,7 @@ func Read(content []byte) (hook *Hook, err error) {
 }
 
 // Validate performs load-time hook validation.
-func (hook *Hook) Validate() (err error) {
+func (hook *Hook) Validate(extensionStages []string) (err error) {
 	if hook == nil {
 		return errors.New("nil hook")
 	}
@@ -68,6 +68,10 @@ func (hook *Hook) Validate() (err error) {
 	}
 
 	validStages := map[string]bool{"prestart": true, "poststart": true, "poststop": true}
+	for _, stage := range extensionStages {
+		validStages[stage] = true
+	}
+
 	for _, stage := range hook.Stages {
 		if !validStages[stage] {
 			return fmt.Errorf("unknown stage %q", stage)
diff --git a/pkg/hooks/1.0.0/hook_test.go b/pkg/hooks/1.0.0/hook_test.go
index 003be34bb..bd6d6b654 100644
--- a/pkg/hooks/1.0.0/hook_test.go
+++ b/pkg/hooks/1.0.0/hook_test.go
@@ -51,7 +51,7 @@ func TestGoodValidate(t *testing.T) {
 		},
 		Stages: []string{"prestart"},
 	}
-	err := hook.Validate()
+	err := hook.Validate([]string{})
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -59,7 +59,7 @@ func TestGoodValidate(t *testing.T) {
 
 func TestNilValidation(t *testing.T) {
 	var hook *Hook
-	err := hook.Validate()
+	err := hook.Validate([]string{})
 	if err == nil {
 		t.Fatal("unexpected success")
 	}
@@ -68,7 +68,7 @@ func TestNilValidation(t *testing.T) {
 
 func TestWrongVersion(t *testing.T) {
 	hook := Hook{Version: "0.1.0"}
-	err := hook.Validate()
+	err := hook.Validate([]string{})
 	if err == nil {
 		t.Fatal("unexpected success")
 	}
@@ -80,7 +80,7 @@ func TestNoHookPath(t *testing.T) {
 		Version: "1.0.0",
 		Hook:    rspec.Hook{},
 	}
-	err := hook.Validate()
+	err := hook.Validate([]string{})
 	if err == nil {
 		t.Fatal("unexpected success")
 	}
@@ -94,7 +94,7 @@ func TestUnknownHookPath(t *testing.T) {
 			Path: filepath.Join("does", "not", "exist"),
 		},
 	}
-	err := hook.Validate()
+	err := hook.Validate([]string{})
 	if err == nil {
 		t.Fatal("unexpected success")
 	}
@@ -111,7 +111,7 @@ func TestNoStages(t *testing.T) {
 			Path: path,
 		},
 	}
-	err := hook.Validate()
+	err := hook.Validate([]string{})
 	if err == nil {
 		t.Fatal("unexpected success")
 	}
@@ -126,13 +126,27 @@ func TestInvalidStage(t *testing.T) {
 		},
 		Stages: []string{"does-not-exist"},
 	}
-	err := hook.Validate()
+	err := hook.Validate([]string{})
 	if err == nil {
 		t.Fatal("unexpected success")
 	}
 	assert.Regexp(t, "^unknown stage \"does-not-exist\"$", err.Error())
 }
 
+func TestExtensionStage(t *testing.T) {
+	hook := Hook{
+		Version: "1.0.0",
+		Hook: rspec.Hook{
+			Path: path,
+		},
+		Stages: []string{"prestart", "b"},
+	}
+	err := hook.Validate([]string{"a", "b", "c"})
+	if err != nil {
+		t.Fatal(err)
+	}
+}
+
 func TestInvalidAnnotationKey(t *testing.T) {
 	hook := Hook{
 		Version: "1.0.0",
@@ -146,7 +160,7 @@ func TestInvalidAnnotationKey(t *testing.T) {
 		},
 		Stages: []string{"prestart"},
 	}
-	err := hook.Validate()
+	err := hook.Validate([]string{})
 	if err == nil {
 		t.Fatal("unexpected success")
 	}
@@ -166,7 +180,7 @@ func TestInvalidAnnotationValue(t *testing.T) {
 		},
 		Stages: []string{"prestart"},
 	}
-	err := hook.Validate()
+	err := hook.Validate([]string{})
 	if err == nil {
 		t.Fatal("unexpected success")
 	}
@@ -184,7 +198,7 @@ func TestInvalidCommand(t *testing.T) {
 		},
 		Stages: []string{"prestart"},
 	}
-	err := hook.Validate()
+	err := hook.Validate([]string{})
 	if err == nil {
 		t.Fatal("unexpected success")
 	}