Added support for group based node volume binds + refactoring

cli/commands.go

@@ -148,30 +148,9 @@ func CreateCluster(c *cli.Context) error {
 	}
 	volumes := c.StringSlice("volume")
 
-	volumesSpec := Volumes{
-		DefaultVolumes:      []string{},
-		NodeSpecificVolumes: make(map[string][]string),
-	}
-	for _, volume := range volumes {
-		if strings.Contains(volume, "@") {
-			split := strings.Split(volume, "@")
-			if len(split) != 2 {
-				return fmt.Errorf("invalid node volume spec: %s", volume)
-			}
-
-			nodeVolumes := split[0]
-			node := split[1]
-			if len(node) == 0 {
-				return fmt.Errorf("invalid node volume spec: %s", volume)
-			}
-
-			if _, ok := volumesSpec.NodeSpecificVolumes[node]; !ok {
-				volumesSpec.NodeSpecificVolumes[node] = []string{}
-			}
-			volumesSpec.NodeSpecificVolumes[node] = append(volumesSpec.NodeSpecificVolumes[node], nodeVolumes)
-		} else {
-			volumesSpec.DefaultVolumes = append(volumesSpec.DefaultVolumes, volume)
-		}
+	volumesSpec, err := NewVolumes(volumes)
+	if err != nil {
+		return err
 	}
 
 	volumesSpec.DefaultVolumes = append(volumesSpec.DefaultVolumes, fmt.Sprintf("%s:/images", imageVolume.Name))

cli/container.go

@@ -30,7 +30,7 @@ type ClusterSpec struct {
 	NodeToPortSpecMap map[string][]string
 	PortAutoOffset    int
 	ServerArgs        []string
-	Volumes           Volumes
+	Volumes           *Volumes
 }
 
 func startContainer(config *container.Config, hostConfig *container.HostConfig, networkingConfig *network.NetworkingConfig, containerName string) (string, error) {
@@ -118,7 +118,7 @@ func createServer(spec *ClusterSpec) (string, error) {
 		hostConfig.RestartPolicy.Name = "unless-stopped"
 	}
 
-	addVolumesToHostConfig(spec.Volumes, containerName, hostConfig)
+	spec.Volumes.addVolumesToHostConfig(containerName, "server", hostConfig)
 
 	networkingConfig := &network.NetworkingConfig{
 		EndpointsConfig: map[string]*network.EndpointSettings{
@@ -185,7 +185,7 @@ func createWorker(spec *ClusterSpec, postfix int) (string, error) {
 		hostConfig.RestartPolicy.Name = "unless-stopped"
 	}
 
-	addVolumesToHostConfig(spec.Volumes, containerName, hostConfig)
+	spec.Volumes.addVolumesToHostConfig(containerName, "worker", hostConfig)
 
 	networkingConfig := &network.NetworkingConfig{
 		EndpointsConfig: map[string]*network.EndpointSettings{
@@ -230,17 +230,3 @@ func removeContainer(ID string) error {
 	}
 	return nil
 }
-
-// addVolumesToHostConfig adds all default volumes and node specific volumes to a HostConfig
-func addVolumesToHostConfig(volumesSpec Volumes, containerName string, hostConfig *container.HostConfig) {
-	if len(volumesSpec.DefaultVolumes) > 0 {
-		volumes := volumesSpec.DefaultVolumes
-
-		// add node specific volumes if present
-		if v, ok := volumesSpec.NodeSpecificVolumes[containerName]; ok {
-			volumes = append(volumes, v...)
-		}
-
-		hostConfig.Binds = volumes
-	}
-}

cli/port.go

@@ -14,15 +14,6 @@ type PublishedPorts struct {
 	PortBindings map[nat.Port][]nat.PortBinding
 }
 
-// defaultNodes describes the type of nodes on which a port should be exposed by default
-const defaultNodes = "server"
-
-// mapping a node role to groups that should be applied to it
-var nodeRuleGroupsMap = map[string][]string{
-	"worker": {"all", "workers"},
-	"server": {"all", "server", "master"},
-}
-
 // mapNodesToPortSpecs maps nodes to portSpecs
 func mapNodesToPortSpecs(specs []string, createdNodes []string) (map[string][]string, error) {
 

cli/util.go

@@ -15,11 +15,6 @@ type apiPort struct {
 	Port   string
 }
 
-type Volumes struct {
-	DefaultVolumes      []string
-	NodeSpecificVolumes map[string][]string
-}
-
 const letterBytes = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
 const (
 	letterIdxBits = 6                    // 6 bits to represent a letter index
@@ -27,6 +22,15 @@ const (
 	letterIdxMax  = 63 / letterIdxBits   // # of letter indices fitting in 63 bits
 )
 
+// defaultNodes describes the default node group (master)
+const defaultNodes = "server"
+
+// mapping a node role to groups that should be applied to it
+var nodeRuleGroupsMap = map[string][]string{
+	"worker": {"all", "workers"},
+	"server": {"all", "server", "master"},
+}
+
 var src = rand.NewSource(time.Now().UnixNano())
 
 // GenerateRandomString thanks to https://stackoverflow.com/a/31832326/6450189

cli/volume.go

@@ -3,13 +3,21 @@ package run
 import (
 	"context"
 	"fmt"
+	"strings"
 
 	"github.com/docker/docker/api/types"
+	"github.com/docker/docker/api/types/container"
 	"github.com/docker/docker/api/types/filters"
 	"github.com/docker/docker/api/types/volume"
 	"github.com/docker/docker/client"
 )
 
+type Volumes struct {
+	DefaultVolumes       []string
+	NodeSpecificVolumes  map[string][]string
+	GroupSpecificVolumes map[string][]string
+}
+
 // createImageVolume will create a new docker volume used for storing image tarballs that can be loaded into the clusters
 func createImageVolume(clusterName string) (types.Volume, error) {
 
@@ -90,3 +98,68 @@ func getImageVolume(clusterName string) (types.Volume, error) {
 
 	return vol, nil
 }
+
+func NewVolumes(volumes []string) (*Volumes, error) {
+	volumesSpec := &Volumes{
+		DefaultVolumes:       []string{},
+		NodeSpecificVolumes:  make(map[string][]string),
+		GroupSpecificVolumes: make(map[string][]string),
+	}
+	for _, volume := range volumes {
+		if strings.Contains(volume, "@") {
+			split := strings.Split(volume, "@")
+			if len(split) != 2 {
+				return nil, fmt.Errorf("invalid node volume spec: %s", volume)
+			}
+
+			nodeVolumes := split[0]
+			node := strings.ToLower(split[1])
+			if len(node) == 0 {
+				return nil, fmt.Errorf("invalid node volume spec: %s", volume)
+			}
+
+			// check if node selector is a node group
+			if _, ok := nodeRuleGroupsMap[node]; ok {
+				volumesSpec.addGroupSpecificVolume(node, nodeVolumes)
+			}
+
+			// otherwise this is a volume for a specific node
+			volumesSpec.addNodeSpecificVolume(node, nodeVolumes)
+		} else {
+			volumesSpec.DefaultVolumes = append(volumesSpec.DefaultVolumes, volume)
+		}
+	}
+
+	return volumesSpec, nil
+}
+
+// addVolumesToHostConfig adds all default volumes and node / group specific volumes to a HostConfig
+func (v Volumes) addVolumesToHostConfig(containerName string, groupName string, hostConfig *container.HostConfig) {
+	volumes := v.DefaultVolumes
+
+	if v, ok := v.NodeSpecificVolumes[containerName]; ok {
+		volumes = append(volumes, v...)
+	}
+
+	if v, ok := v.GroupSpecificVolumes[groupName]; ok {
+		volumes = append(volumes, v...)
+	}
+
+	if len(volumes) > 0 {
+		hostConfig.Binds = volumes
+	}
+}
+
+func (v *Volumes) addNodeSpecificVolume(node, volume string) {
+	if _, ok := v.NodeSpecificVolumes[node]; !ok {
+		v.NodeSpecificVolumes[node] = []string{}
+	}
+	v.NodeSpecificVolumes[node] = append(v.NodeSpecificVolumes[node], volume)
+}
+
+func (v *Volumes) addGroupSpecificVolume(group, volume string) {
+	if _, ok := v.GroupSpecificVolumes[group]; !ok {
+		v.GroupSpecificVolumes[group] = []string{}
+	}
+	v.GroupSpecificVolumes[group] = append(v.GroupSpecificVolumes[group], volume)
+}