82 lines
2.4 KiB
Go
82 lines
2.4 KiB
Go
// Copyright 2016 CNI 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 version
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import (
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"encoding/json"
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"fmt"
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"io"
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)
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// PluginInfo reports information about CNI versioning
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type PluginInfo interface {
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// SupportedVersions returns one or more CNI spec versions that the plugin
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// supports. If input is provided in one of these versions, then the plugin
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// promises to use the same CNI version in its response
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SupportedVersions() []string
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// Encode writes this CNI version information as JSON to the given Writer
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Encode(io.Writer) error
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}
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type pluginInfo struct {
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CNIVersion_ string `json:"cniVersion"`
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SupportedVersions_ []string `json:"supportedVersions,omitempty"`
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}
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// pluginInfo implements the PluginInfo interface
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var _ PluginInfo = &pluginInfo{}
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func (p *pluginInfo) Encode(w io.Writer) error {
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return json.NewEncoder(w).Encode(p)
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}
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func (p *pluginInfo) SupportedVersions() []string {
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return p.SupportedVersions_
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}
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// PluginSupports returns a new PluginInfo that will report the given versions
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// as supported
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func PluginSupports(supportedVersions ...string) PluginInfo {
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if len(supportedVersions) < 1 {
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panic("programmer error: you must support at least one version")
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}
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return &pluginInfo{
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CNIVersion_: Current(),
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SupportedVersions_: supportedVersions,
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}
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}
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// PluginDecoder can decode the response returned by a plugin's VERSION command
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type PluginDecoder struct{}
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func (*PluginDecoder) Decode(jsonBytes []byte) (PluginInfo, error) {
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var info pluginInfo
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err := json.Unmarshal(jsonBytes, &info)
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if err != nil {
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return nil, fmt.Errorf("decoding version info: %s", err)
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}
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if info.CNIVersion_ == "" {
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return nil, fmt.Errorf("decoding version info: missing field cniVersion")
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}
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if len(info.SupportedVersions_) == 0 {
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if info.CNIVersion_ == "0.2.0" {
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return PluginSupports("0.1.0", "0.2.0"), nil
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}
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return nil, fmt.Errorf("decoding version info: missing field supportedVersions")
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}
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return &info, nil
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}
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