added hash check for node edit

Signed-off-by: Christian Goll <cgoll@suse.de>

internal/pkg/api/node/edit.go

@@ -24,6 +24,7 @@ func FindAllNodeConfs() *wwapiv1.NodeYaml {
 	buffer, _ := yaml.Marshal(nodeMap)
 	retVal := wwapiv1.NodeYaml{
 		NodeConfMapYaml: string(buffer),
+		Hash:            nodeDB.StringHash(),
 	}
 	return &retVal
 }
@@ -42,6 +43,7 @@ func FilteredNodes(nodeList *wwapiv1.NodeList) *wwapiv1.NodeYaml {
 	buffer, _ := yaml.Marshal(nodeMap)
 	retVal := wwapiv1.NodeYaml{
 		NodeConfMapYaml: string(buffer),
+		Hash:            nodeDB.StringHash(),
 	}
 	return &retVal
 }

internal/pkg/api/node/hash.go

@@ -0,0 +1,20 @@
+package apinode
+
+import (
+	"encoding/hex"
+
+	"github.com/hpcng/warewulf/internal/pkg/api/routes/wwapiv1"
+	"github.com/hpcng/warewulf/internal/pkg/node"
+	"github.com/hpcng/warewulf/internal/pkg/wwlog"
+)
+
+func Hash() *wwapiv1.NodeDBHash {
+	config, err := node.New()
+	if err != nil {
+		wwlog.Warn("couldb't read config")
+	}
+	hash := config.Hash()
+	return &wwapiv1.NodeDBHash{
+		Hash: hex.EncodeToString(hash[:]),
+	}
+}

internal/pkg/api/node/node.go

@@ -1,6 +1,7 @@
 package apinode
 
 import (
+	"encoding/hex"
 	"encoding/json"
 	"fmt"
 	"net/http"
@@ -29,7 +30,10 @@ func NodeAdd(nap *wwapiv1.NodeAddParameter) (err error) {
 	if err != nil {
 		return errors.Wrap(err, "failed to open node database")
 	}
-
+	dbHash := nodeDB.Hash()
+	if hex.EncodeToString(dbHash[:]) != nap.Hash && !nap.Force {
+		return fmt.Errorf("got wrong hash, not modifying node database")
+	}
 	node_args := hostlist.Expand(nap.NodeNames)
 	var nodeConf node.NodeConf
 	err = yaml.Unmarshal([]byte(nap.NodeConfYaml), &nodeConf)
@@ -95,6 +99,10 @@ func NodeDelete(ndp *wwapiv1.NodeDeleteParameter) (err error) {
 		wwlog.Error("Failed to open node database: %s", err)
 		return
 	}
+	dbHash := nodeDB.Hash()
+	if hex.EncodeToString(dbHash[:]) != ndp.Hash && !ndp.Force {
+		return fmt.Errorf("got wrong hash, not modifying node database")
+	}
 
 	for _, n := range nodeList {
 		err := nodeDB.DelNode(n.Id.Get())
@@ -133,6 +141,13 @@ func NodeDeleteParameterCheck(ndp *wwapiv1.NodeDeleteParameter, console bool) (n
 		wwlog.Error("Failed to open node database: %s", err)
 		return
 	}
+	dbHash := nodeDB.Hash()
+	if hex.EncodeToString(dbHash[:]) != ndp.Hash && !ndp.Force {
+		wwlog.Debug("got hash: %s", ndp.Hash)
+		wwlog.Debug("actual hash: %s", hex.EncodeToString(dbHash[:]))
+		err = fmt.Errorf("got wrong hash, not modifying node database")
+		return
+	}
 
 	nodes, err := nodeDB.FindAllNodes()
 	if err != nil {

internal/pkg/api/routes/v1/routes.proto

@@ -10,6 +10,12 @@ package wwapi.v1;
 import "google/protobuf/empty.proto";
 import "google/api/annotations.proto";
 
+// Information about the database
+
+message NodeDBHash {
+	string hash = 1;
+}
+
 // Container
 
 // ContainerBuildParameter contains input for building zero or more containers.
@@ -133,9 +139,12 @@ message ProfileList {
 }
 
 // NodeAddParameter contains all input for adding a node to be managed by
-// Warewulf.
+// Warewulf. Only adds nodes if the hash matches the actual hash of the 
+// configuration.
 message NodeAddParameter {
 	string nodeConfYaml = 1;
+	bool force = 2;
+	string hash = 3;
 	repeated string nodeNames = 10;
 }
 
@@ -143,13 +152,17 @@ message NodeAddParameter {
 // to nodes.conf (is resused for profile edit)
 message NodeYaml {
 	string nodeConfMapYaml = 1;
+	string hash = 2;
 }
 
 // NodeDeleteParameter contains input for removing nodes from Warewulf
-// management.
+// management. If the given hash differs with the actual hash of the 
+// configuration, no node is deleted. The force option allows the deletion
+// of nodes with a correct hash.
 message NodeDeleteParameter {
 	bool force = 1;
 	repeated string nodeNames = 2;
+	string hash = 3;
 }
 
 // NodeSetParameter contains all fields for updating aspects of nodes managed