Add helper functions to work with Ignition Configs

pkg/controller/common/helpers.go

@@ -658,3 +658,60 @@ func dedupePasswdUserSSHKeys(passwdUser ign2types.PasswdUser) ign2types.PasswdUs
 
 	return passwdUser
 }
+
+// CalculateConfigFileDiffs compares the files present in two ignition configurations and returns the list of files
+// that are different between them
+func CalculateConfigFileDiffs(oldIgnConfig, newIgnConfig *ign3types.Config) []string {
+	// Go through the files and see what is new or different
+	oldFileSet := make(map[string]ign3types.File)
+	for _, f := range oldIgnConfig.Storage.Files {
+		oldFileSet[f.Path] = f
+	}
+	newFileSet := make(map[string]ign3types.File)
+	for _, f := range newIgnConfig.Storage.Files {
+		newFileSet[f.Path] = f
+	}
+	diffFileSet := []string{}
+
+	// First check if any files were removed
+	for path := range oldFileSet {
+		_, ok := newFileSet[path]
+		if !ok {
+			// debug: remove
+			glog.Infof("File diff: %v was deleted", path)
+			diffFileSet = append(diffFileSet, path)
+		}
+	}
+
+	// Now check if any files were added/changed
+	for path, newFile := range newFileSet {
+		oldFile, ok := oldFileSet[path]
+		if !ok {
+			// debug: remove
+			glog.Infof("File diff: %v was added", path)
+			diffFileSet = append(diffFileSet, path)
+		} else if !reflect.DeepEqual(oldFile, newFile) {
+			// debug: remove
+			glog.Infof("File diff: detected change to %v", newFile.Path)
+			diffFileSet = append(diffFileSet, path)
+		}
+	}
+	return diffFileSet
+}
+
+// GetIgnitionFileDataByPath retrieves the file data for a specified path from a given ignition config
+func GetIgnitionFileDataByPath(config *ign3types.Config, path string) ([]byte, error) {
+	for _, f := range config.Storage.Files {
+		if path == f.Path {
+			// Convert whatever we have to the actual bytes so we can inspect them
+			if f.Contents.Source != nil {
+				contents, err := dataurl.DecodeString(*f.Contents.Source)
+				if err != nil {
+					return nil, err
+				}
+				return contents.Data, err
+			}
+		}
+	}
+	return nil, nil
+}

pkg/controller/common/helpers_test.go

@@ -1,6 +1,7 @@
 package common
 
 import (
+	"reflect"
 	"testing"
 
 	"github.com/clarketm/json"
@@ -380,3 +381,32 @@ func TestRemoveIgnDuplicateFilesAndUnits(t *testing.T) {
 
 	assert.Equal(t, expectedIgn2Config, convertedIgn2Config)
 }
+
+func TestCalculateConfigFileDiffs(t *testing.T) {
+	var testIgn3ConfigOld ign3types.Config
+	var testIgn3ConfigNew ign3types.Config
+
+	oldTempFile := helpers.NewIgnFile("/etc/kubernetes/kubelet-ca.crt", "oldcertificates")
+	newTempFile := helpers.NewIgnFile("/etc/kubernetes/kubelet-ca.crt", "newcertificates")
+
+	// Make an "old" config with the existing file in it
+	testIgn3ConfigOld.Ignition.Version = "3.2.0"
+	testIgn3ConfigOld.Storage.Files = append(testIgn3ConfigOld.Storage.Files, oldTempFile)
+
+	// Make a "new" config with a change to that file
+	testIgn3ConfigNew.Ignition.Version = "3.2.0"
+	testIgn3ConfigNew.Storage.Files = append(testIgn3ConfigNew.Storage.Files, newTempFile)
+
+	// If it works, it should notice the file changed
+	expectedDiffFileSet := []string{"/etc/kubernetes/kubelet-ca.crt"}
+	actualDiffFileSet := CalculateConfigFileDiffs(&testIgn3ConfigOld, &testIgn3ConfigNew)
+	unchangedDiffFileset := CalculateConfigFileDiffs(&testIgn3ConfigOld, &testIgn3ConfigOld)
+
+	if !reflect.DeepEqual(expectedDiffFileSet, actualDiffFileSet) {
+		t.Errorf("Actual file diff: %s did not match expected: %s", actualDiffFileSet, expectedDiffFileSet)
+	}
+
+	if !reflect.DeepEqual(unchangedDiffFileset, []string{}) {
+		t.Errorf("File changes detected where there should have been none: %s", unchangedDiffFileset)
+	}
+}

pkg/daemon/update_test.go

@@ -582,35 +582,22 @@ func TestDropinCheck(t *testing.T) {
 	}
 }
 
-func newFile(path, contents string) ign3types.File {
-	return ign3types.File{
-		Node: ign3types.Node{
-			Path: path,
-		},
-		FileEmbedded1: ign3types.FileEmbedded1{
-			Contents: ign3types.Resource{
-				Source: helpers.StrToPtr(dataurl.EncodeBytes([]byte(contents))),
-			},
-		},
-	}
-}
-
 // Test to see if the correct action is calculated given a machineconfig diff
 // i.e. whether we need to reboot and what actions need to be taken if no reboot is needed
 func TestCalculatePostConfigChangeAction(t *testing.T) {
 	files := map[string]ign3types.File{
-		"pullsecret1":     newFile("/var/lib/kubelet/config.json", "kubelet conf 1\n"),
-		"pullsecret2":     newFile("/var/lib/kubelet/config.json", "kubelet conf 2\n"),
-		"registries1":     newFile("/etc/containers/registries.conf", "registries content 1\n"),
-		"registries2":     newFile("/etc/containers/registries.conf", "registries content 2\n"),
-		"randomfile1":     newFile("/etc/random-reboot-file", "test\n"),
-		"randomfile2":     newFile("/etc/random-reboot-file", "test 2\n"),
-		"kubeletCA1":      newFile("/etc/kubernetes/kubelet-ca.crt", "kubeletCA1\n"),
-		"kubeletCA2":      newFile("/etc/kubernetes/kubelet-ca.crt", "kubeletCA2\n"),
-		"policy1":         newFile("/etc/containers/policy.json", "policy1"),
-		"policy2":         newFile("/etc/containers/policy.json", "policy2"),
-		"containers-gpg1": newFile("/etc/machine-config-daemon/no-reboot/containers-gpg.pub", "containers-gpg1"),
-		"containers-gpg2": newFile("/etc/machine-config-daemon/no-reboot/containers-gpg.pub", "containers-gpg2"),
+		"pullsecret1":     helpers.NewIgnFile("/var/lib/kubelet/config.json", "kubelet conf 1\n"),
+		"pullsecret2":     helpers.NewIgnFile("/var/lib/kubelet/config.json", "kubelet conf 2\n"),
+		"registries1":     helpers.NewIgnFile("/etc/containers/registries.conf", "registries content 1\n"),
+		"registries2":     helpers.NewIgnFile("/etc/containers/registries.conf", "registries content 2\n"),
+		"randomfile1":     helpers.NewIgnFile("/etc/random-reboot-file", "test\n"),
+		"randomfile2":     helpers.NewIgnFile("/etc/random-reboot-file", "test 2\n"),
+		"kubeletCA1":      helpers.NewIgnFile("/etc/kubernetes/kubelet-ca.crt", "kubeletCA1\n"),
+		"kubeletCA2":      helpers.NewIgnFile("/etc/kubernetes/kubelet-ca.crt", "kubeletCA2\n"),
+		"policy1":         helpers.NewIgnFile("/etc/containers/policy.json", "policy1"),
+		"policy2":         helpers.NewIgnFile("/etc/containers/policy.json", "policy2"),
+		"containers-gpg1": helpers.NewIgnFile("/etc/machine-config-daemon/no-reboot/containers-gpg.pub", "containers-gpg1"),
+		"containers-gpg2": helpers.NewIgnFile("/etc/machine-config-daemon/no-reboot/containers-gpg.pub", "containers-gpg2"),
 	}
 
 	tests := []struct {

test/helpers/helpers.go

@@ -5,6 +5,7 @@ import (
 
 	"github.com/clarketm/json"
 	ign3types "github.com/coreos/ignition/v2/config/v3_2/types"
+	"github.com/vincent-petithory/dataurl"
 	corev1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
@@ -150,6 +151,19 @@ func NewMachineConfigPool(name string, mcSelector, nodeSelector *metav1.LabelSel
 	}
 }
 
+// NewIgnFile returns a simple ignition3 file from just path and file contents
+func NewIgnFile(path, contents string) ign3types.File {
+	return ign3types.File{
+		Node: ign3types.Node{
+			Path: path,
+		},
+		FileEmbedded1: ign3types.FileEmbedded1{
+			Contents: ign3types.Resource{
+				Source: StrToPtr(dataurl.EncodeBytes([]byte(contents)))},
+		},
+	}
+}
+
 // CreateMachineConfigFromIgnition returns a MachineConfig object from an Ignition config passed to it
 func CreateMachineConfigFromIgnition(ignCfg interface{}) *mcfgv1.MachineConfig {
 	return &mcfgv1.MachineConfig{