35c086fa6b
Absorb Swarm's discovery package in order to provide a common node discovery mechanism to be used by both Swarm and networking code. Signed-off-by: Arnaud Porterie <arnaud.porterie@docker.com>
53 lines
1.4 KiB
Go
53 lines
1.4 KiB
Go
package discovery
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import (
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"fmt"
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"strings"
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"time"
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log "github.com/Sirupsen/logrus"
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)
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var (
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// Backends is a global map of discovery backends indexed by their
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// associated scheme.
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backends map[string]Backend
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)
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func init() {
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backends = make(map[string]Backend)
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}
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// Register makes a discovery backend available by the provided scheme.
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// If Register is called twice with the same scheme an error is returned.
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func Register(scheme string, d Backend) error {
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if _, exists := backends[scheme]; exists {
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return fmt.Errorf("scheme already registered %s", scheme)
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}
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log.WithField("name", scheme).Debug("Registering discovery service")
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backends[scheme] = d
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return nil
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}
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func parse(rawurl string) (string, string) {
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parts := strings.SplitN(rawurl, "://", 2)
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// nodes:port,node2:port => nodes://node1:port,node2:port
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if len(parts) == 1 {
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return "nodes", parts[0]
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}
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return parts[0], parts[1]
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}
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// New returns a new Discovery given a URL, heartbeat and ttl settings.
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// Returns an error if the URL scheme is not supported.
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func New(rawurl string, heartbeat time.Duration, ttl time.Duration) (Backend, error) {
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scheme, uri := parse(rawurl)
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if backend, exists := backends[scheme]; exists {
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log.WithFields(log.Fields{"name": scheme, "uri": uri}).Debug("Initializing discovery service")
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err := backend.Initialize(uri, heartbeat, ttl)
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return backend, err
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}
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return nil, ErrNotSupported
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}
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