mirror of
https://github.com/k3s-io/k3s.git
synced 2024-06-07 19:41:36 +00:00
94 lines
2.1 KiB
Go
94 lines
2.1 KiB
Go
// Copyright 2015 flannel authors
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package backend
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import (
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"fmt"
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"strings"
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"sync"
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"github.com/flannel-io/flannel/subnet"
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"golang.org/x/net/context"
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)
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var constructors = make(map[string]BackendCtor)
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type Manager interface {
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GetBackend(backendType string) (Backend, error)
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}
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type manager struct {
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ctx context.Context
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sm subnet.Manager
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extIface *ExternalInterface
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mux sync.Mutex
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active map[string]Backend
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wg sync.WaitGroup
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}
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func NewManager(ctx context.Context, sm subnet.Manager, extIface *ExternalInterface) Manager {
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return &manager{
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ctx: ctx,
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sm: sm,
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extIface: extIface,
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active: make(map[string]Backend),
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}
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}
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func (bm *manager) GetBackend(backendType string) (Backend, error) {
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bm.mux.Lock()
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defer bm.mux.Unlock()
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betype := strings.ToLower(backendType)
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// see if one is already running
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if be, ok := bm.active[betype]; ok {
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return be, nil
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}
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// first request, need to create and run it
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befunc, ok := constructors[betype]
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if !ok {
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return nil, fmt.Errorf("unknown backend type: %v", betype)
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}
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be, err := befunc(bm.sm, bm.extIface)
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if err != nil {
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return nil, err
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}
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bm.active[betype] = be
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bm.wg.Add(1)
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go func() {
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<-bm.ctx.Done()
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// TODO(eyakubovich): this obviosly introduces a race.
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// GetBackend() could get called while we are here.
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// Currently though, all backends' Run exit only
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// on shutdown
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bm.mux.Lock()
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delete(bm.active, betype)
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bm.mux.Unlock()
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bm.wg.Done()
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}()
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return be, nil
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}
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func Register(name string, ctor BackendCtor) {
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constructors[name] = ctor
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}
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