docker/daemon/links.go

129 строки
3.8 KiB
Go

package daemon
import (
"strings"
"sync"
"github.com/Sirupsen/logrus"
"github.com/docker/docker/container"
"github.com/docker/docker/pkg/graphdb"
)
// linkIndex stores link relationships between containers, including their specified alias
// The alias is the name the parent uses to reference the child
type linkIndex struct {
// idx maps a parent->alias->child relationship
idx map[*container.Container]map[string]*container.Container
// childIdx maps child->parent->aliases
childIdx map[*container.Container]map[*container.Container]map[string]struct{}
mu sync.Mutex
}
func newLinkIndex() *linkIndex {
return &linkIndex{
idx: make(map[*container.Container]map[string]*container.Container),
childIdx: make(map[*container.Container]map[*container.Container]map[string]struct{}),
}
}
// link adds indexes for the passed in parent/child/alias relationships
func (l *linkIndex) link(parent, child *container.Container, alias string) {
l.mu.Lock()
if l.idx[parent] == nil {
l.idx[parent] = make(map[string]*container.Container)
}
l.idx[parent][alias] = child
if l.childIdx[child] == nil {
l.childIdx[child] = make(map[*container.Container]map[string]struct{})
}
if l.childIdx[child][parent] == nil {
l.childIdx[child][parent] = make(map[string]struct{})
}
l.childIdx[child][parent][alias] = struct{}{}
l.mu.Unlock()
}
// unlink removes the requested alias for the given parent/child
func (l *linkIndex) unlink(alias string, child, parent *container.Container) {
l.mu.Lock()
delete(l.idx[parent], alias)
delete(l.childIdx[child], parent)
l.mu.Unlock()
}
// children maps all the aliases-> children for the passed in parent
// aliases here are the aliases the parent uses to refer to the child
func (l *linkIndex) children(parent *container.Container) map[string]*container.Container {
l.mu.Lock()
children := l.idx[parent]
l.mu.Unlock()
return children
}
// parents maps all the aliases->parent for the passed in child
// aliases here are the aliases the parents use to refer to the child
func (l *linkIndex) parents(child *container.Container) map[string]*container.Container {
l.mu.Lock()
parents := make(map[string]*container.Container)
for parent, aliases := range l.childIdx[child] {
for alias := range aliases {
parents[alias] = parent
}
}
l.mu.Unlock()
return parents
}
// delete deletes all link relationships referencing this container
func (l *linkIndex) delete(container *container.Container) {
l.mu.Lock()
for _, child := range l.idx[container] {
delete(l.childIdx[child], container)
}
delete(l.idx, container)
delete(l.childIdx, container)
l.mu.Unlock()
}
// migrateLegacySqliteLinks migrates sqlite links to use links from HostConfig
// when sqlite links were used, hostConfig.Links was set to nil
func (daemon *Daemon) migrateLegacySqliteLinks(db *graphdb.Database, container *container.Container) error {
// if links is populated (or an empty slice), then this isn't using sqlite links and can be skipped
if container.HostConfig == nil || container.HostConfig.Links != nil {
return nil
}
logrus.Debugf("migrating legacy sqlite link info for container: %s", container.ID)
fullName := container.Name
if fullName[0] != '/' {
fullName = "/" + fullName
}
// don't use a nil slice, this ensures that the check above will skip once the migration has completed
links := []string{}
children, err := db.Children(fullName, 0)
if err != nil {
if !strings.Contains(err.Error(), "Cannot find child for") {
return err
}
// else continue... it's ok if we didn't find any children, it'll just be nil and we can continue the migration
}
for _, child := range children {
c, err := daemon.GetContainer(child.Entity.ID())
if err != nil {
return err
}
links = append(links, c.Name+":"+child.Edge.Name)
}
container.HostConfig.Links = links
return container.WriteHostConfig()
}