forked from flynn/flynn
/
discoverd.go
97 lines (89 loc) · 2.54 KB
/
discoverd.go
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package cli
import (
"errors"
"fmt"
"log"
"net"
"net/url"
"strings"
"github.com/flynn/flynn/discoverd/client"
"github.com/flynn/flynn/pkg/cluster"
"github.com/flynn/go-docopt"
)
func init() {
Register("promote", runPromote, `
usage: flynn-host promote ADDR
Promotes a Flynn node to a member of the consensus cluster.
`)
Register("demote", runDemote, `
usage: flynn-host demote [-f|--force] ADDR
Demotes a Flynn node, removing it from the consensus cluster.
`)
}
func runPromote(args *docopt.Args, client *cluster.Client) error {
addr, err := formatAddr(args.String["ADDR"])
if err != nil {
return err
}
dd := discoverd.NewClientWithURL(addr)
if err := dd.Promote(addr); err != nil {
return err
}
log.Println("Promoted peer", addr)
log.Println("NOTE: If you have made changes to the peer set that you intend to be permanent you should update the discoverd environment variable DISCOVERD_PEERS to reflect this.")
return nil
}
func runDemote(args *docopt.Args, client *cluster.Client) error {
addr, err := formatAddr(args.String["ADDR"])
if err != nil {
return err
}
force := args.Bool["--force"]
// first try to connect to the peer and gracefully demote it
dd := discoverd.NewClientWithURL(addr)
err = dd.Ping(addr)
if err == nil {
log.Println("Attempting to gracefully demote peer.")
err = dd.Demote(addr)
} else if !force {
return errors.New("Failed to contact peer to attempt graceful demotion and --force not given.")
}
// if that fails and --force is given forcefully remove it
// by instructing the raft leader to remove it from the raft peers directly
if err != nil && force {
leader, err := discoverd.DefaultClient.RaftLeader()
if err != nil {
return err
}
dd = discoverd.NewClientWithURL(leader.Host)
if err := dd.RaftRemovePeer(addr); err != nil {
return err
}
log.Println("Forcefully removed peer", addr)
return nil
} else if err != nil {
return err
}
log.Println("Demoted peer", addr)
log.Println("NOTE: If you have made changes to the peer set that you intend to be permanent you should update the discoverd environment variable DISCOVERD_PEERS to reflect this.")
return nil
}
func formatAddr(addr string) (string, error) {
if !strings.HasPrefix(addr, "http") {
addr = "http://" + addr
}
parsed, err := url.Parse(addr)
if err != nil {
fmt.Println("error in parsing addr err:", err)
return "", err
}
host, port, _ := net.SplitHostPort(parsed.Host)
if host == "" {
host = parsed.Host
}
if port == "" {
port = "1111"
}
parsed.Host = net.JoinHostPort(host, port)
return parsed.String(), nil
}