open-consul/agent/router/serf_flooder.go

114 lines
3.1 KiB
Go

package router
import (
"fmt"
"net"
"strings"
"github.com/hashicorp/consul/agent/metadata"
"github.com/hashicorp/go-hclog"
"github.com/hashicorp/serf/serf"
)
// FloodAddrFn gets the address to use for a given server when flood-joining. This
// will return false if it doesn't have one.
type FloodAddrFn func(*metadata.Server) (string, bool)
// FloodPortFn gets the port to use for a given server when flood-joining. This
// will return false if it doesn't have one.
type FloodPortFn func(*metadata.Server) (int, bool)
// FloodJoins attempts to make sure all Consul servers in the local Serf
// instance are joined in the global Serf instance. It assumes names in the
// local area are of the form <node> and those in the global area are of the
// form <node>.<dc> as is done for WAN and general network areas in Consul
// Enterprise.
func FloodJoins(logger hclog.Logger, addrFn FloodAddrFn, portFn FloodPortFn,
localDatacenter string, localSerf *serf.Serf, globalSerf *serf.Serf) {
// Names in the global Serf have the datacenter suffixed.
suffix := fmt.Sprintf(".%s", localDatacenter)
// Index the global side so we can do one pass through the local side
// with cheap lookups.
index := make(map[string]*metadata.Server)
for _, m := range globalSerf.Members() {
ok, server := metadata.IsConsulServer(m)
if !ok {
continue
}
if server.Datacenter != localDatacenter {
continue
}
localName := strings.TrimSuffix(server.Name, suffix)
index[localName] = server
}
// Now run through the local side and look for joins.
for _, m := range localSerf.Members() {
if m.Status != serf.StatusAlive {
continue
}
ok, server := metadata.IsConsulServer(m)
if !ok {
continue
}
if _, ok := index[server.Name]; ok {
continue
}
// We can't use the port number from the local Serf, so we just
// get the host part.
addr, _, err := net.SplitHostPort(server.Addr.String())
if err != nil {
logger.Debug("Failed to flood-join server (bad address)",
"server", server.Name,
"address", server.Addr.String(),
"error", err,
)
}
if addrFn != nil {
if a, ok := addrFn(server); ok {
addr = a
}
}
// Let the callback see if it can get the port number, otherwise
// leave it blank to behave as if we just supplied an address.
if port, ok := portFn(server); ok {
addr = net.JoinHostPort(addr, fmt.Sprintf("%d", port))
} else {
// If we have an IPv6 address, we should add brackets,
// single globalSerf.Join expects that.
if ip := net.ParseIP(addr); ip != nil {
if ip.To4() == nil {
addr = fmt.Sprintf("[%s]", addr)
}
} else {
logger.Debug("Failed to parse IP", "ip", addr)
}
}
globalServerName := fmt.Sprintf("%s.%s", server.Name, server.Datacenter)
// Do the join!
n, err := globalSerf.Join([]string{globalServerName + "/" + addr}, true)
if err != nil {
logger.Debug("Failed to flood-join server at address",
"server", globalServerName,
"address", addr,
"error", err,
)
} else if n > 0 {
logger.Debug("Successfully performed flood-join for server at address",
"server", globalServerName,
"address", addr,
)
}
}
}