// FromEnv uses the environment to create a new Me.
//
// To use this, a client MUST be running inside of a Pod environment. It uses
// a combination of environment variables and file paths to determine
// information about the cluster.
func FromEnv() (*Me, error) {
host := os.Getenv("KUBERNETES_SERVICE_HOST")
port := os.Getenv("KUBERNETES_SERVICE_PORT")
name := NameFromEnv()
// FIXME: Better way? Probably scanning secrets for
// an SSL cert would help?
proto := "https"
url := proto + "://" + host + ":" + port
me := &Me{
ApiServer: url,
Name: name,
Namespace: NamespaceFromEnv(),
}
client, err := k8s.PodClient()
if err != nil {
return me, err
}
me.c = client
if err := me.init(); err != nil {
return me, err
}
return me, nil
}
// RemoveStaleMembers deletes cluster members whose pods are no longer running.
//
// This queries Kubernetes to determine what etcd pods are running, and then
// compares that to the member list in the etcd cluster. It removes any
// cluster members who are no longer in the pod list.
//
// The purpose of this is to keep the cluster membership from deadlocking
// when inactive members prevent consensus building.
//
// Params:
// - client (etcd/client.Client): The etcd client
// - label (string): The pod label indicating an etcd node
// - namespace (string): The namespace we're operating in
func RemoveStaleMembers(c cookoo.Context, p *cookoo.Params) (interface{}, cookoo.Interrupt) {
eclient := p.Get("client", nil).(client.Client)
label := p.Get("label", "name=deis-etcd-1").(string)
ns := p.Get("namespace", "default").(string)
// Should probably pass in the client from the context.
klient, err := k8s.PodClient()
if err != nil {
log.Errf(c, "Could not create a Kubernetes client: %s", err)
return nil, err
}
mapi := client.NewMembersAPI(eclient)
members := map[string]bool{}
idmap := map[string]string{}
// Get members from etcd
mm, err := mapi.List(dctx())
if err != nil {
log.Warnf(c, "Could not get a list of etcd members: %s", err)
return nil, err
}
for _, member := range mm {
members[member.Name] = false
idmap[member.Name] = member.ID
}
// Get the pods running with the given label
labelSelector, err := labels.Parse(label)
if err != nil {
log.Errf(c, "Selector failed to parse: %s", err)
return nil, err
}
pods, err := klient.Pods(ns).List(api.ListOptions{LabelSelector: labelSelector})
if err != nil {
return nil, err
}
for _, item := range pods.Items {
if _, ok := members[item.Name]; !ok {
log.Infof(c, "Etcd pod %s is not in cluster yet.", item.Name)
} else {
members[item.Name] = true
}
}
// Anything marked false in members should be removed from etcd.
deleted := 0
for k, v := range members {
if !v {
log.Infof(c, "Deleting %s (%s) from etcd cluster members", k, idmap[k])
if err := mapi.Remove(dctx(), idmap[k]); err != nil {
log.Errf(c, "Failed to remove %s from cluster. Skipping. %s", k, err)
} else {
deleted++
}
}
}
return deleted, nil
}
