consul/watch/funcs.go

167 lines
4.4 KiB
Go

package watch
import (
"fmt"
"github.com/armon/consul-api"
)
// watchFactory is a function that can create a new WatchFunc
// from a parameter configuration
type watchFactory func(params map[string]interface{}) (WatchFunc, error)
// watchFuncFactory maps each type to a factory function
var watchFuncFactory map[string]watchFactory
func init() {
watchFuncFactory = map[string]watchFactory{
"key": keyWatch,
"keyprefix": keyPrefixWatch,
"services": servicesWatch,
"nodes": nodesWatch,
"service": serviceWatch,
"checks": checksWatch,
}
}
// keyWatch is used to return a key watching function
func keyWatch(params map[string]interface{}) (WatchFunc, error) {
var key string
if err := assignValue(params, "key", &key); err != nil {
return nil, err
}
if key == "" {
return nil, fmt.Errorf("Must specify a single key to watch")
}
fn := func(p *WatchPlan) (uint64, interface{}, error) {
kv := p.client.KV()
opts := consulapi.QueryOptions{WaitIndex: p.lastIndex}
pair, meta, err := kv.Get(key, &opts)
if err != nil {
return 0, nil, err
}
if pair == nil {
return meta.LastIndex, nil, err
}
return meta.LastIndex, pair, err
}
return fn, nil
}
// keyPrefixWatch is used to return a key prefix watching function
func keyPrefixWatch(params map[string]interface{}) (WatchFunc, error) {
var prefix string
if err := assignValue(params, "prefix", &prefix); err != nil {
return nil, err
}
if prefix == "" {
return nil, fmt.Errorf("Must specify a single prefix to watch")
}
fn := func(p *WatchPlan) (uint64, interface{}, error) {
kv := p.client.KV()
opts := consulapi.QueryOptions{WaitIndex: p.lastIndex}
pairs, meta, err := kv.List(prefix, &opts)
if err != nil {
return 0, nil, err
}
return meta.LastIndex, pairs, err
}
return fn, nil
}
// servicesWatch is used to watch the list of available services
func servicesWatch(params map[string]interface{}) (WatchFunc, error) {
fn := func(p *WatchPlan) (uint64, interface{}, error) {
catalog := p.client.Catalog()
opts := consulapi.QueryOptions{WaitIndex: p.lastIndex}
services, meta, err := catalog.Services(&opts)
if err != nil {
return 0, nil, err
}
return meta.LastIndex, services, err
}
return fn, nil
}
// nodesWatch is used to watch the list of available nodes
func nodesWatch(params map[string]interface{}) (WatchFunc, error) {
fn := func(p *WatchPlan) (uint64, interface{}, error) {
catalog := p.client.Catalog()
opts := consulapi.QueryOptions{WaitIndex: p.lastIndex}
nodes, meta, err := catalog.Nodes(&opts)
if err != nil {
return 0, nil, err
}
return meta.LastIndex, nodes, err
}
return fn, nil
}
// serviceWatch is used to watch a specific service for changes
func serviceWatch(params map[string]interface{}) (WatchFunc, error) {
var service, tag string
if err := assignValue(params, "service", &service); err != nil {
return nil, err
}
if service == "" {
return nil, fmt.Errorf("Must specify a single service to watch")
}
if err := assignValue(params, "tag", &tag); err != nil {
return nil, err
}
passingOnly := false
if err := assignValueBool(params, "passingonly", &passingOnly); err != nil {
return nil, err
}
fn := func(p *WatchPlan) (uint64, interface{}, error) {
health := p.client.Health()
opts := consulapi.QueryOptions{WaitIndex: p.lastIndex}
nodes, meta, err := health.Service(service, tag, passingOnly, &opts)
if err != nil {
return 0, nil, err
}
return meta.LastIndex, nodes, err
}
return fn, nil
}
// checksWatch is used to watch a specific checks in a given state
func checksWatch(params map[string]interface{}) (WatchFunc, error) {
var service, state string
if err := assignValue(params, "service", &service); err != nil {
return nil, err
}
if err := assignValue(params, "state", &state); err != nil {
return nil, err
}
if service != "" && state != "" {
return nil, fmt.Errorf("Cannot specify service and state")
}
if service == "" && state == "" {
state = "any"
}
fn := func(p *WatchPlan) (uint64, interface{}, error) {
health := p.client.Health()
opts := consulapi.QueryOptions{WaitIndex: p.lastIndex}
var checks []*consulapi.HealthCheck
var meta *consulapi.QueryMeta
var err error
if state != "" {
checks, meta, err = health.State(state, &opts)
} else {
checks, meta, err = health.Checks(service, &opts)
}
if err != nil {
return 0, nil, err
}
return meta.LastIndex, checks, err
}
return fn, nil
}