Add filter to limit available resources.

scheduler/filter/filter.go

@@ -34,6 +34,7 @@ func init() {
 		&DependencyFilter{},
 		&AffinityFilter{},
 		&ConstraintFilter{},
+		&ResourceFilter{},
 	}
 }
 

scheduler/filter/resource.go

@@ -0,0 +1,64 @@
+package filter
+
+import (
+	"fmt"
+	log "github.com/Sirupsen/logrus"
+	"github.com/docker/swarm/cluster"
+	"github.com/docker/swarm/scheduler/node"
+	"os"
+	"strconv"
+)
+
+// ResourceFilter selects only nodes based on other containers on the node.
+type ResourceFilter struct {
+}
+
+// Name returns the name of the filter
+func (f *ResourceFilter) Name() string {
+	return "resource"
+}
+
+// Filter is exported
+func (f *ResourceFilter) Filter(config *cluster.ContainerConfig, nodes []*node.Node, _ bool) ([]*node.Node, error) {
+	availableMemory, err := strconv.ParseInt(os.Getenv("SWARM_NODE_MEMORY_LIMIT_MB"), 10, 64)
+	if err != nil {
+		log.Warning("Swarm node memory limit was not set.")
+		availableMemory = -1
+	} else {
+		availableMemory = availableMemory * 1024 * 1024
+	}
+	availableCpu, err := strconv.ParseInt(os.Getenv("SWARM_NODE_CPU_LIMIT"), 10, 64)
+	if err != nil {
+		log.Warning("Swarm node CPU limit was not set.")
+		availableCpu = -1
+	}
+	containerMemory := config.HostConfig.Memory
+	containerCpu := config.HostConfig.CPUShares
+	candidates := []*node.Node{}
+	var memoryLimit int64
+	var cpuLimit int64
+	for _, node := range nodes {
+		if availableMemory < 0 || availableMemory > node.TotalMemory {
+			memoryLimit = node.TotalMemory
+		} else {
+			memoryLimit = availableMemory
+		}
+		if availableCpu < 0 || availableCpu > node.TotalCpus {
+			cpuLimit = node.TotalCpus
+		} else {
+			cpuLimit = availableCpu
+		}
+		if node.UsedMemory+containerMemory <= memoryLimit && node.UsedCpus+containerCpu <= cpuLimit {
+			candidates = append(candidates, node)
+		}
+	}
+	if len(candidates) == 0 {
+		return nil, fmt.Errorf("No resources available to place container.")
+	}
+	return candidates, nil
+}
+
+// GetFilters returns resources info.
+func (f *ResourceFilter) GetFilters(config *cluster.ContainerConfig) ([]string, error) {
+	return []string{fmt.Sprintf("Memory=%d CPU=%d", config.HostConfig.Memory, config.HostConfig.CPUShares)}, nil
+}