// serviceConfig constructs the config for all good instances of a single service.
func serviceConfig(client *api.Client, name string, passing map[string]bool, tagPrefix string) (config []string) {
if name == "" || len(passing) == 0 {
return nil
}
q := &api.QueryOptions{RequireConsistent: true}
svcs, _, err := client.Catalog().Service(name, "", q)
if err != nil {
log.Printf("[WARN] [%s] Error getting catalog service %s. %v", name, err)
return nil
}
for _, svc := range svcs {
// check if the instance is in the list of instances
// which passed the health check
if _, ok := passing[svc.ServiceID]; !ok {
continue
}
for _, tag := range svc.ServiceTags {
if host, path, ok := parseURLPrefixTag(tag, tagPrefix); ok {
name, addr, port := svc.ServiceName, svc.ServiceAddress, svc.ServicePort
if runtime.GOOS == "darwin" && !strings.Contains(addr, ".") {
addr += ".local"
}
config = append(config, fmt.Sprintf("route add %s %s%s http://%s:%d/ tags %q", name, host, path, addr, port, strings.Join(svc.ServiceTags, ",")))
}
}
}
return config
}
func putKV(client *api.Client, key, value string, index uint64) (bool, error) {
p := &api.KVPair{Key: key[1:], Value: []byte(value), ModifyIndex: index}
ok, _, err := client.KV().CAS(p, nil)
if err != nil {
return false, err
}
return ok, nil
}
func getKV(client *api.Client, key string, waitIndex uint64) (string, uint64, error) {
q := &api.QueryOptions{RequireConsistent: true, WaitIndex: waitIndex}
kvpair, meta, err := client.KV().Get(key, q)
if err != nil {
return "", 0, err
}
if kvpair == nil {
return "", meta.LastIndex, nil
}
return strings.TrimSpace(string(kvpair.Value)), meta.LastIndex, nil
}
// datacenter returns the datacenter of the local agent
func datacenter(c *api.Client) (string, error) {
self, err := c.Agent().Self()
if err != nil {
return "", err
}
cfg, ok := self["Config"]
if !ok {
return "", errors.New("consul: self.Config not found")
}
dc, ok := cfg["Datacenter"].(string)
if !ok {
return "", errors.New("consul: self.Datacenter not found")
}
return dc, nil
}
// watchAutoConfig monitors the consul health checks and creates a new configuration
// on every change.
func watchAutoConfig(client *api.Client, tagPrefix string, config chan []string) {
var lastIndex uint64
for {
q := &api.QueryOptions{RequireConsistent: true, WaitIndex: lastIndex}
checks, meta, err := client.Health().State("passing", q)
if err != nil {
log.Printf("[WARN] Error fetching health state. %v", err)
time.Sleep(time.Second)
continue
}
log.Printf("[INFO] Health changed to #%d", meta.LastIndex)
config <- servicesConfig(client, checks, tagPrefix)
lastIndex = meta.LastIndex
}
}
func nextValue(client *api.Client, path string, lastIndex uint64) (string, uint64) {
for {
q := &api.QueryOptions{RequireConsistent: true, WaitIndex: lastIndex}
kvpair, meta, err := client.KV().Get(path, q)
if err != nil {
log.Printf("[WARN] Error fetching config from %s. %v", path, err)
time.Sleep(time.Second)
continue
}
if kvpair == nil {
return "", meta.LastIndex
}
return strings.TrimSpace(string(kvpair.Value)), meta.LastIndex
}
}
