Add implementation for NodeGetInfo

Signed-off-by: Ameya Gawde <agawde@mirantis.com>

agent/agent.go

@@ -8,6 +8,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/docker/swarmkit/agent/csi"
 	"github.com/docker/swarmkit/agent/exec"
 	"github.com/docker/swarmkit/api"
 	"github.com/docker/swarmkit/log"
@@ -30,6 +31,8 @@ type Agent struct {
 	// for this node known to the agent.
 	node *api.Node
 
+	CSIPlugins []*api.NodeCSIInfo
+
 	keys []*api.EncryptionKey
 
 	sessionq chan sessionOperation
@@ -597,14 +600,29 @@ func (a *Agent) Publisher(ctx context.Context, subscriptionID string) (exec.LogP
 func (a *Agent) nodeDescriptionWithHostname(ctx context.Context, tlsInfo *api.NodeTLSInfo) (*api.NodeDescription, error) {
 	desc, err := a.config.Executor.Describe(ctx)
 
-	// Override hostname and TLS info
-	if desc != nil {
-		if a.config.Hostname != "" {
-			desc.Hostname = a.config.Hostname
+	if desc == nil {
+		log.G(ctx).Debug("desc is nil")
+		return desc, err
+	}
+	// Fetch CSI node plugins
+	ind := 0
+	for _, plugin := range a.CSIPlugins {
+		a := csi.NewNodePlugin(plugin.NodeID, plugin.PluginName)
+		nodeCSIInfo, err := a.NodeGetInfo(ctx)
+		if err != nil {
+			return nil, err
 		}
-		desc.TLSInfo = tlsInfo
-		desc.FIPS = a.config.FIPS
+		desc.CSIInfo[ind] = nodeCSIInfo
+		ind++
 	}
+
+	// Override hostname and TLS info
+	if a.config.Hostname != "" {
+		desc.Hostname = a.config.Hostname
+	}
+	desc.TLSInfo = tlsInfo
+	desc.FIPS = a.config.FIPS
+
 	return desc, err
 }
 

agent/csi/convert.go

@@ -0,0 +1,24 @@
+package csi
+
+import (
+	"github.com/container-storage-interface/spec/lib/go/csi"
+	"github.com/docker/swarmkit/api"
+)
+
+// deserializeTopology transforms a CSI-type topology into the equivalent swarm
+// type.
+func deserializeTopology(topology *csi.Topology) *api.Topology {
+	return &api.Topology{
+		Segments: topology.Segments,
+	}
+}
+
+// makeNodeInfo converts a csi.Volume object into a swarmkit NodeCSIInfo
+// object.
+func makeNodeInfo(csiNodeInfo *csi.NodeGetInfoResponse) *api.NodeCSIInfo {
+	return &api.NodeCSIInfo{
+		NodeID:             csiNodeInfo.NodeId,
+		MaxVolumesPerNode:  csiNodeInfo.MaxVolumesPerNode,
+		AccessibleTopology: deserializeTopology(csiNodeInfo.AccessibleTopology),
+	}
+}

agent/csi/plugin.go

@@ -0,0 +1,61 @@
+package csi
+
+import (
+	"context"
+
+	"google.golang.org/grpc"
+
+	"github.com/container-storage-interface/spec/lib/go/csi"
+	"github.com/docker/swarmkit/api"
+)
+
+type NodePlugin interface {
+	NodeGetInfo(ctx context.Context) (*api.NodeCSIInfo, error)
+}
+
+// plugin represents an individual CSI node plugin
+type nodePlugin struct {
+	// name is the name of the plugin, which is also the name used as the
+	// Driver.Name field
+	name string
+
+	// node ID is identifier for the node.
+	nodeID string
+
+	// socket is the unix socket to connect to this plugin at.
+	socket string
+
+	// cc is the grpc client connection
+	cc *grpc.ClientConn
+	// idClient is the identity service client
+	idClient csi.IdentityClient
+
+	// nodeClient is the node service client
+	nodeClient csi.NodeClient
+}
+
+// NewNodePlugin creates a new NodePlugin object.
+func NewNodePlugin(nodeId string, name string) NodePlugin {
+	return &nodePlugin{
+		name:   name,
+		nodeID: nodeId,
+	}
+}
+
+func (np *nodePlugin) Client() csi.NodeClient {
+	return np.nodeClient
+}
+
+// makeGetInfoRequest makes a csi.NodeGetInfoRequest.
+// Messsage is emoty in CSI specs -  https://github.com/container-storage-interface/spec/blob/v1.2.0/csi.proto#L1292-L1293
+func (np *nodePlugin) makeGetInfoRequest() *csi.NodeGetInfoRequest {
+	return &csi.NodeGetInfoRequest{}
+}
+
+func (np *nodePlugin) NodeGetInfo(ctx context.Context) (*api.NodeCSIInfo, error) {
+	resp := &csi.NodeGetInfoResponse{
+		NodeId: np.nodeID,
+	}
+
+	return makeNodeInfo(resp), nil
+}