/
store.go
341 lines (264 loc) · 6.78 KB
/
store.go
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package knuckles
import (
"fmt"
"github.com/fiorix/go-redis/redis"
"strconv"
"time"
)
type Endpoint struct {
addr string
}
type Store interface {
EndpointForHostname(name string) (Endpoint, error)
AddApplication(app string) error
AddHostname(app, hostname string) error
AddBackend(app, backend string, ttl int) error
EnableBackend(app, backend string) error
DisableBackend(app, backend string) error
HostnamesForApp(app string) ([]string, error)
BackendsForApp(app string) ([]string, error)
RemoveApplication(name string) error
RemoveHostname(app, hostname string) error
RemoveBackend(app, backend string) error
ListApplications() ([]string, error)
DescribeApplication(app string) ([]string, map[string]bool, error)
}
type RedisStore struct {
client *redis.Client
namespace string
}
func NewRedisStore(namespace string, host string) (*RedisStore, error) {
r := &RedisStore{
namespace: namespace,
}
r.client = redis.New(host)
return r, nil
}
func (r *RedisStore) EndpointForHostname(name string) (Endpoint, error) {
var epoint Endpoint
appName, err := r.client.Get(r.Key("resolve:%s", name))
if err != nil {
return epoint, err
}
if appName == "" {
return epoint, ErrNoHostname
}
members, err := r.client.SRandMember(r.Key("live_backend:%s", appName), 1)
if err != nil {
return epoint, err
}
if len(members) != 1 {
return epoint, ErrNoBackend
}
epoint.addr = members[0]
return epoint, nil
}
func (r *RedisStore) Key(format string, args ...interface{}) string {
return r.namespace + fmt.Sprintf(format, args...)
}
func (r *RedisStore) AddApplication(app string) error {
ok, err := r.client.SAdd(r.Key("apps"), app)
if err != nil {
return err
}
if ok == 0 {
return ErrAppAlreadyExists
}
return nil
}
func (r *RedisStore) isValidApp(app string) error {
ismember, err := r.client.SIsMember(r.Key("apps"), app)
if err != nil {
return err
}
if ismember == 0 {
return ErrNoApp
}
return nil
}
func (r *RedisStore) isValidBackend(app, backend string) error {
ismember, err := r.client.SIsMember(r.Key("backend:%s", app), backend)
if err != nil {
return err
}
if ismember == 0 {
return ErrNoBackend
}
// check if this guy needs to be removed (ttl)
rawTTL, err := r.client.Get(r.Key("backend_ttl:%s:%s", app, backend))
if err != nil {
return err
}
// if the backend has been dead for more than X seconds
// and it hasn't pinged us, get rid of it
if rawTTL != "" {
now := int(time.Now().Unix())
ttl, err := strconv.Atoi(rawTTL)
if err == nil {
if now > ttl {
err = r.RemoveBackend(app, backend)
if err != nil {
return err
}
//make sure this backend doesn't get activated
return ErrNoBackend
}
}
}
return nil
}
func (r *RedisStore) EnableBackend(app, backend string) error {
err := r.isValidApp(app)
if err != nil {
return err
}
err = r.isValidBackend(app, backend)
if err != nil {
return err
}
_, err = r.client.SAdd(r.Key("live_backend:%s", app), backend)
return err
}
func (r *RedisStore) DisableBackend(app, backend string) error {
err := r.isValidApp(app)
if err != nil {
return err
}
err = r.isValidBackend(app, backend)
if err != nil {
return err
}
_, err = r.client.SRem(r.Key("live_backend:%s", app), backend)
return err
}
func (r *RedisStore) AddHostname(app, hostname string) error {
err := r.isValidApp(app)
if err != nil {
return err
}
ok, err := r.client.SetNx(r.Key("resolve:%s", hostname), app)
if err != nil {
return err
}
if ok == 0 {
return ErrHostnameAlreadyExists
}
_, err = r.client.SAdd(r.Key("hostname:%s", app), hostname)
return err
}
func (r *RedisStore) AddBackend(app, backend string, ttl int) error {
err := r.isValidApp(app)
if err != nil {
return err
}
ismember, err := r.client.SIsMember(r.Key("backends:%s", app), backend)
if err != nil {
return err
}
if ismember == 1 {
return ErrBackendAlreadyExists
}
if ttl > 0 {
expire := int(time.Now().Unix()) + ttl
err = r.client.Set(r.Key("backend_ttl:%s:%s", app, backend), strconv.Itoa(expire))
if err != nil {
return err
}
}
_, err = r.client.SAdd(r.Key("backend:%s", app), backend)
if err != nil {
return err
}
return r.EnableBackend(app, backend)
}
func (r *RedisStore) HostnamesForApp(app string) ([]string, error) {
return r.client.SMembers(r.Key("hostname:%s", app))
}
func (r *RedisStore) BackendsForApp(app string) ([]string, error) {
return r.client.SMembers(r.Key("backend:%s", app))
}
func (r *RedisStore) RemoveBackend(app, backend string) error {
err := r.isValidApp(app)
if err != nil {
return err
}
_, err = r.client.Del(r.Key("backend_ttl:%s:%s", app, backend))
if err != nil {
return err
}
_, err = r.client.SRem(r.Key("live_backend:%s", app), backend)
if err != nil {
return err
}
_, err = r.client.SRem(r.Key("backend:%s", app), backend)
return err
}
func (r *RedisStore) RemoveHostname(app, hostname string) error {
err := r.isValidApp(app)
if err != nil {
return err
}
_, err = r.client.SRem(r.Key("hostname:%s", app), hostname)
if err != nil {
return err
}
_, err = r.client.Del(r.Key("resolve:%s", hostname))
return err
}
func (r *RedisStore) RemoveApplication(app string) error {
err := r.isValidApp(app)
if err != nil {
return err
}
_, err = r.client.Del(r.Key("backend:%s", app))
if err != nil {
return err
}
hostnames, err := r.HostnamesForApp(app)
for _, h := range hostnames {
_, err = r.client.Del(r.Key("resolve:%s", h))
if err != nil {
return err
}
}
_, err = r.client.Del(r.Key("hostname:%s", app))
if err != nil {
return err
}
_, err = r.client.SRem(r.Key("apps"), app)
return err
}
func (r *RedisStore) ListApplications() ([]string, error) {
return r.client.SMembers(r.Key("apps"))
}
func (r *RedisStore) DescribeApplication(app string) ([]string, map[string]bool, error) {
var hostnames []string
var backends = make(map[string]bool)
err := r.isValidApp(app)
if err != nil {
return hostnames, backends, err
}
hostnames, err = r.client.SMembers(r.Key("hostname:%s", app))
if err != nil {
return hostnames, backends, err
}
backendList, err := r.client.SMembers(r.Key("backend:%s", app))
if err != nil {
return hostnames, backends, err
}
for _, backend := range backendList {
ok, err := r.client.SIsMember(r.Key("live_backend:%s", app), backend)
if err != nil {
return hostnames, backends, err
}
if ok > 0 {
backends[backend] = true
} else {
backends[backend] = false
}
}
return hostnames, backends, nil
}
func (epoint *Endpoint) Addr() string {
return epoint.addr
}