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moby--moby/plugin/store.go
Boaz Shuster 36ebf9489c Refactor plugin store to reduce nested if's in Get
This patch removes the nested if's  in the Get function
and makes the code more readable.

Signed-off-by: Boaz Shuster <ripcurld.github@gmail.com>
2017-10-09 22:21:27 +03:00

248 lines
6.5 KiB
Go

package plugin
import (
"fmt"
"strings"
"github.com/docker/distribution/reference"
"github.com/docker/docker/pkg/plugingetter"
"github.com/docker/docker/pkg/plugins"
"github.com/docker/docker/plugin/v2"
"github.com/pkg/errors"
"github.com/sirupsen/logrus"
)
/* allowV1PluginsFallback determines daemon's support for V1 plugins.
* When the time comes to remove support for V1 plugins, flipping
* this bool is all that will be needed.
*/
const allowV1PluginsFallback bool = true
/* defaultAPIVersion is the version of the plugin API for volume, network,
IPAM and authz. This is a very stable API. When we update this API, then
pluginType should include a version. e.g. "networkdriver/2.0".
*/
const defaultAPIVersion string = "1.0"
// GetV2Plugin retrieves a plugin by name, id or partial ID.
func (ps *Store) GetV2Plugin(refOrID string) (*v2.Plugin, error) {
ps.RLock()
defer ps.RUnlock()
id, err := ps.resolvePluginID(refOrID)
if err != nil {
return nil, err
}
p, idOk := ps.plugins[id]
if !idOk {
return nil, errors.WithStack(errNotFound(id))
}
return p, nil
}
// validateName returns error if name is already reserved. always call with lock and full name
func (ps *Store) validateName(name string) error {
for _, p := range ps.plugins {
if p.Name() == name {
return alreadyExistsError(name)
}
}
return nil
}
// GetAll retrieves all plugins.
func (ps *Store) GetAll() map[string]*v2.Plugin {
ps.RLock()
defer ps.RUnlock()
return ps.plugins
}
// SetAll initialized plugins during daemon restore.
func (ps *Store) SetAll(plugins map[string]*v2.Plugin) {
ps.Lock()
defer ps.Unlock()
ps.plugins = plugins
}
func (ps *Store) getAllByCap(capability string) []plugingetter.CompatPlugin {
ps.RLock()
defer ps.RUnlock()
result := make([]plugingetter.CompatPlugin, 0, 1)
for _, p := range ps.plugins {
if p.IsEnabled() {
if _, err := p.FilterByCap(capability); err == nil {
result = append(result, p)
}
}
}
return result
}
// SetState sets the active state of the plugin and updates plugindb.
func (ps *Store) SetState(p *v2.Plugin, state bool) {
ps.Lock()
defer ps.Unlock()
p.PluginObj.Enabled = state
}
// Add adds a plugin to memory and plugindb.
// An error will be returned if there is a collision.
func (ps *Store) Add(p *v2.Plugin) error {
ps.Lock()
defer ps.Unlock()
if v, exist := ps.plugins[p.GetID()]; exist {
return fmt.Errorf("plugin %q has the same ID %s as %q", p.Name(), p.GetID(), v.Name())
}
ps.plugins[p.GetID()] = p
return nil
}
// Remove removes a plugin from memory and plugindb.
func (ps *Store) Remove(p *v2.Plugin) {
ps.Lock()
delete(ps.plugins, p.GetID())
ps.Unlock()
}
// Get returns an enabled plugin matching the given name and capability.
func (ps *Store) Get(name, capability string, mode int) (plugingetter.CompatPlugin, error) {
// Lookup using new model.
if ps != nil {
p, err := ps.GetV2Plugin(name)
if err == nil {
p.AddRefCount(mode)
if p.IsEnabled() {
return p.FilterByCap(capability)
}
// Plugin was found but it is disabled, so we should not fall back to legacy plugins
// but we should error out right away
return nil, errDisabled(name)
}
if _, ok := errors.Cause(err).(errNotFound); !ok {
return nil, err
}
}
if !allowV1PluginsFallback {
return nil, errNotFound(name)
}
p, err := plugins.Get(name, capability)
if err == nil {
return p, nil
}
if errors.Cause(err) == plugins.ErrNotFound {
return nil, errNotFound(name)
}
return nil, errors.Wrap(systemError{err}, "legacy plugin")
}
// GetAllManagedPluginsByCap returns a list of managed plugins matching the given capability.
func (ps *Store) GetAllManagedPluginsByCap(capability string) []plugingetter.CompatPlugin {
return ps.getAllByCap(capability)
}
// GetAllByCap returns a list of enabled plugins matching the given capability.
func (ps *Store) GetAllByCap(capability string) ([]plugingetter.CompatPlugin, error) {
result := make([]plugingetter.CompatPlugin, 0, 1)
/* Daemon start always calls plugin.Init thereby initializing a store.
* So store on experimental builds can never be nil, even while
* handling legacy plugins. However, there are legacy plugin unit
* tests where the volume subsystem directly talks with the plugin,
* bypassing the daemon. For such tests, this check is necessary.
*/
if ps != nil {
ps.RLock()
result = ps.getAllByCap(capability)
ps.RUnlock()
}
// Lookup with legacy model
if allowV1PluginsFallback {
pl, err := plugins.GetAll(capability)
if err != nil {
return nil, errors.Wrap(systemError{err}, "legacy plugin")
}
for _, p := range pl {
result = append(result, p)
}
}
return result, nil
}
// Handle sets a callback for a given capability. It is only used by network
// and ipam drivers during plugin registration. The callback registers the
// driver with the subsystem (network, ipam).
func (ps *Store) Handle(capability string, callback func(string, *plugins.Client)) {
pluginType := fmt.Sprintf("docker.%s/%s", strings.ToLower(capability), defaultAPIVersion)
// Register callback with new plugin model.
ps.Lock()
handlers, ok := ps.handlers[pluginType]
if !ok {
handlers = []func(string, *plugins.Client){}
}
handlers = append(handlers, callback)
ps.handlers[pluginType] = handlers
ps.Unlock()
// Register callback with legacy plugin model.
if allowV1PluginsFallback {
plugins.Handle(capability, callback)
}
}
// CallHandler calls the registered callback. It is invoked during plugin enable.
func (ps *Store) CallHandler(p *v2.Plugin) {
for _, typ := range p.GetTypes() {
for _, handler := range ps.handlers[typ.String()] {
handler(p.Name(), p.Client())
}
}
}
func (ps *Store) resolvePluginID(idOrName string) (string, error) {
ps.RLock() // todo: fix
defer ps.RUnlock()
if validFullID.MatchString(idOrName) {
return idOrName, nil
}
ref, err := reference.ParseNormalizedNamed(idOrName)
if err != nil {
return "", errors.WithStack(errNotFound(idOrName))
}
if _, ok := ref.(reference.Canonical); ok {
logrus.Warnf("canonical references cannot be resolved: %v", reference.FamiliarString(ref))
return "", errors.WithStack(errNotFound(idOrName))
}
ref = reference.TagNameOnly(ref)
for _, p := range ps.plugins {
if p.PluginObj.Name == reference.FamiliarString(ref) {
return p.PluginObj.ID, nil
}
}
var found *v2.Plugin
for id, p := range ps.plugins { // this can be optimized
if strings.HasPrefix(id, idOrName) {
if found != nil {
return "", errors.WithStack(errAmbiguous(idOrName))
}
found = p
}
}
if found == nil {
return "", errors.WithStack(errNotFound(idOrName))
}
return found.PluginObj.ID, nil
}