docs/scheduler/filter/filter.go

106 lines
2.4 KiB
Go

package filter
import (
"errors"
"fmt"
log "github.com/Sirupsen/logrus"
"github.com/docker/swarm/cluster"
"github.com/docker/swarm/scheduler/node"
)
// Filter is exported
type Filter interface {
Name() string
// Return a subset of nodes that were accepted by the filtering policy.
Filter(*cluster.ContainerConfig, []*node.Node, bool) ([]*node.Node, error)
// Return a list of constraints/filters provided
GetFilters(*cluster.ContainerConfig) ([]string, error)
}
var (
filters []Filter
// ErrNotSupported is exported
ErrNotSupported = errors.New("filter not supported")
)
func init() {
filters = []Filter{
&HealthFilter{},
&PortFilter{},
&SlotsFilter{},
&DependencyFilter{},
&AffinityFilter{},
&ConstraintFilter{},
}
}
// New is exported
func New(names []string) ([]Filter, error) {
var selectedFilters []Filter
for _, name := range names {
found := false
for _, filter := range filters {
if filter.Name() == name {
log.WithField("name", name).Debug("Initializing filter")
selectedFilters = append(selectedFilters, filter)
found = true
break
}
}
if !found {
return nil, ErrNotSupported
}
}
return selectedFilters, nil
}
// ApplyFilters applies a set of filters in batch.
func ApplyFilters(filters []Filter, config *cluster.ContainerConfig, nodes []*node.Node, soft bool) ([]*node.Node, error) {
var (
err error
candidates = nodes
)
for _, filter := range filters {
candidates, err = filter.Filter(config, candidates, soft)
if err != nil {
// special case for when no healthy nodes are found
if filter.Name() == "health" {
return nil, err
}
return nil, fmt.Errorf("Unable to find a node that satisfies the following conditions %s", listAllFilters(filters, config, filter.Name()))
}
}
return candidates, nil
}
// listAllFilters creates a string containing all applied filters
func listAllFilters(filters []Filter, config *cluster.ContainerConfig, lastFilter string) string {
allFilters := ""
for _, filter := range filters {
list, err := filter.GetFilters(config)
if err == nil && len(list) > 0 {
allFilters = fmt.Sprintf("%s\n%v", allFilters, list)
}
if filter.Name() == lastFilter {
return allFilters
}
}
return allFilters
}
// List returns the names of all the available filters
func List() []string {
names := []string{}
for _, filter := range filters {
names = append(names, filter.Name())
}
return names
}