add creator pkg for standing up cluster

just has code for local clusters at the moment

creator/creator.go

@@ -0,0 +1,109 @@
+// creator contains code for standing up pilosa clusters
+package creator
+
+import (
+	"fmt"
+	"io/ioutil"
+	"log"
+	"os"
+	"path/filepath"
+	"strconv"
+
+	"github.com/umbel/pilosa"
+)
+
+type Cluster interface {
+	Hosts() []string
+	Shutdown() error
+}
+
+type cluster struct {
+	hosts   []string
+	servers []*pilosa.Server
+	cluster *pilosa.Cluster
+	path    string
+}
+
+func NewLocalCluster(replicaN, serverN int) (Cluster, error) {
+	BasePort := 19327
+
+	localCluster := &cluster{
+		hosts:   make([]string, 0),
+		servers: make([]*pilosa.Server, 0),
+	}
+	path, err := ioutil.TempDir("", "pilosa-bench-")
+	if err != nil {
+		return localCluster, err
+	}
+	localCluster.path = path
+
+	// Build cluster configuration.
+	cluster := pilosa.NewCluster()
+	cluster.ReplicaN = replicaN
+
+	for i := 0; i < serverN; i++ {
+		cluster.Nodes = append(cluster.Nodes, &pilosa.Node{
+			Host: fmt.Sprintf("localhost:%d", BasePort+i),
+		})
+	}
+	localCluster.cluster = cluster
+
+	// Build servers.
+	servers := make([]*pilosa.Server, serverN)
+	for i := range servers {
+		// Make server work directory.
+		if err := os.MkdirAll(filepath.Join(path, strconv.Itoa(i)), 0777); err != nil {
+			return localCluster, err
+		}
+
+		// Build server.
+		s := pilosa.NewServer()
+		s.Host = fmt.Sprintf("localhost:%d", BasePort+i)
+		s.Cluster = cluster
+		s.Index.Path = filepath.Join(path, strconv.Itoa(i), "data")
+
+		// Create log file.
+		f, err := os.Create(filepath.Join(path, strconv.Itoa(i), "log"))
+		if err != nil {
+			return localCluster, err
+		}
+
+		// Set log and optionally write out to stderr as well.
+		s.LogOutput = f
+
+		servers[i] = s
+	}
+	localCluster.servers = servers
+
+	// Open all servers.
+	for _, s := range servers {
+		log.Printf("opening : %v", s)
+		if err := s.Open(); err != nil {
+			return localCluster, err
+		}
+	}
+
+	hosts := make([]string, 0)
+	for _, s := range servers {
+		hosts = append(hosts, s.Host)
+	}
+	localCluster.hosts = hosts
+	return localCluster, nil
+}
+
+func (c *cluster) Hosts() []string { return c.hosts }
+func (c *cluster) Shutdown() error {
+	errs := ""
+	for _, s := range c.servers {
+		if err := s.Close(); err != nil {
+			errs = errs + err.Error() + "; "
+		}
+	}
+	if err := os.RemoveAll(c.path); err != nil {
+		errs = errs + err.Error() + ";"
+	}
+	if errs != "" {
+		return fmt.Errorf(errs)
+	}
+	return nil
+}