98 lines
2.1 KiB
Go
98 lines
2.1 KiB
Go
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package backend
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import (
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"context"
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"fmt"
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"net"
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"strings"
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)
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var factoryMap map[string]Factory
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func init() {
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factoryMap = make(map[string]Factory)
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}
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// Factory backend factory
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type Factory func(map[string]interface{}) (Backend, error)
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// Registry registry backdend
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func Registry(name string, factory Factory) {
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if _, ok := factoryMap[name]; ok {
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panic(fmt.Sprintf("backend %s already exists", name))
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}
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factoryMap[name] = factory
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}
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// New backend
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func New(name string, conf map[string]interface{}) (Backend, error) {
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if factory, ok := factoryMap[name]; ok {
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return factory(conf)
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}
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return nil, fmt.Errorf("backend %s not exists", name)
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}
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// Selector selector
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type Selector struct {
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Env string
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Region string
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Zone string
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Hostname string
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}
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func (s Selector) String() string {
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strs := make([]string, 0, 4)
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if s.Env != "" {
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strs = append(strs, s.Env)
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}
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if s.Region != "" {
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strs = append(strs, s.Region)
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}
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if s.Zone != "" {
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strs = append(strs, s.Zone)
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}
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if s.Hostname != "" {
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strs = append(strs, s.Hostname)
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}
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return strings.Join(strs, "-")
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}
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// Target global unique application identifier
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type Target struct {
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Name string
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}
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func (t Target) String() string {
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return t.Name
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}
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// ParseName parse qname get name and selector
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func ParseName(name string, defaultSel Selector) (target Target, sel Selector, err error) {
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// TODO: support selector
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return Target{Name: name}, defaultSel, nil
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}
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// Metadata metadata contain env, zone, region e.g.
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type Metadata struct {
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ClientHost string
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LatestTimestamps string
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}
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// Instance service instance struct
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type Instance struct {
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Region string `json:"region"`
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Zone string `json:"zone"`
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Env string `json:"env"`
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Hostname string `json:"hostname"`
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DiscoveryID string `json:"discovery_id"`
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TreeID int64 `json:"tree_id"`
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IPAddr net.IP `json:"ip_addr,omitempty"` // hacked field
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}
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// Backend provide service query
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type Backend interface {
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Ping(ctx context.Context) error
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Query(ctx context.Context, target Target, sel Selector, md Metadata) ([]*Instance, error)
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Close(ctx context.Context) error
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}
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