dotcloud/docker

package networkdb

import (
    "context"
    "encoding/json"
    "net"

    "github.com/containerd/log"
    "github.com/hashicorp/memberlist"
)

type eventDelegate struct {
    nDB *NetworkDB
}

func (e *eventDelegate) broadcastNodeEvent(addr net.IP, op opType) {
    value, err := json.Marshal(&NodeAddr{addr})
    if err == nil {
        e.nDB.broadcaster.Write(makeEvent(op, NodeTable, "", "", value))
    } else {
        log.G(context.TODO()).Errorf("Error marshalling node broadcast event %s", addr.String())
    }
}

func (e *eventDelegate) NotifyJoin(mn *memberlist.Node) {
    log.G(context.TODO()).Infof("Node %s/%s, joined gossip cluster", mn.Name, mn.Addr)
    e.broadcastNodeEvent(mn.Addr, opCreate)
    e.nDB.Lock()
    defer e.nDB.Unlock()

    // In case the node is rejoining after a failure or leave,
    // just add the node back to active
    if moved, _ := e.nDB.changeNodeState(mn.Name, nodeActiveState); moved {
        return
    }

    // Every node has a unique ID
    // Check on the base of the IP address if the new node that joined is actually a new incarnation of a previous
    // failed or shutdown one
    e.nDB.purgeReincarnation(mn)

    e.nDB.nodes[mn.Name] = &node{Node: *mn}
    log.G(context.TODO()).Infof("Node %s/%s, added to nodes list", mn.Name, mn.Addr)
}

func (e *eventDelegate) NotifyLeave(mn *memberlist.Node) {
    log.G(context.TODO()).Infof("Node %s/%s, left gossip cluster", mn.Name, mn.Addr)
    e.broadcastNodeEvent(mn.Addr, opDelete)

    e.nDB.Lock()
    defer e.nDB.Unlock()

    n, currState, _ := e.nDB.findNode(mn.Name)
    if n == nil {
        log.G(context.TODO()).Errorf("Node %s/%s not found in the node lists", mn.Name, mn.Addr)
        return
    }
    // if the node was active means that did not send the leave cluster message, so it's probable that
    // failed. Else would be already in the left list so nothing else has to be done
    if currState == nodeActiveState {
        moved, err := e.nDB.changeNodeState(mn.Name, nodeFailedState)
        if err != nil {
            log.G(context.TODO()).WithError(err).Errorf("impossible condition, node %s/%s not present in the list", mn.Name, mn.Addr)
            return
        }
        if moved {
            log.G(context.TODO()).Infof("Node %s/%s, added to failed nodes list", mn.Name, mn.Addr)
        }
    }
}

func (e *eventDelegate) NotifyUpdate(n *memberlist.Node) {
}