func GetURLFromService(spec *APISpec) (*tykcommon.HostList, error) {
doCacheRefresh := func() (*tykcommon.HostList, error) {
log.Debug("--> Refreshing")
spec.ServiceRefreshInProgress = true
sd := ServiceDiscovery{}
sd.New(&spec.Proxy.ServiceDiscovery)
data, err := sd.GetTarget(spec.Proxy.ServiceDiscovery.QueryEndpoint)
if err == nil {
// Set the cached value
if data.Len() == 0 {
spec.HasRun = true
spec.ServiceRefreshInProgress = false
log.Warning("[PROXY][SD] Service Discovery returned empty host list! Returning last good set.")
if spec.LastGoodHostList == nil {
log.Warning("[PROXY][SD] Last good host list is nil, returning empty set.")
spec.LastGoodHostList = tykcommon.NewHostList()
}
return spec.LastGoodHostList, nil
}
ServiceCache.Set(spec.APIID, data, cache.DefaultExpiration)
// Stash it too
spec.LastGoodHostList = data
spec.HasRun = true
spec.ServiceRefreshInProgress = false
return data, err
}
spec.ServiceRefreshInProgress = false
return nil, err
}
// First time? Refresh the cache and return that
if !spec.HasRun {
log.Debug("First run! Setting cache")
return doCacheRefresh()
}
// Not first run - check the cache
cachedServiceData, found := ServiceCache.Get(spec.APIID)
if !found {
if spec.ServiceRefreshInProgress {
// Are we already refreshing the cache? skip and return last good conf
log.Debug("Cache expired! But service refresh in progress")
return spec.LastGoodHostList, nil
}
// Refresh the spec
log.Debug("Cache expired! Refreshing...")
return doCacheRefresh()
}
log.Debug("Returning from cache.")
return cachedServiceData.(*tykcommon.HostList), nil
}
func (s *ServiceDiscovery) ProcessRawData(rawData string) (*tykcommon.HostList, error) {
var jsonParsed gabs.Container
hostlist := tykcommon.NewHostList()
if s.endpointReturnsList {
// Convert to an object
s.ConvertRawListToObj(&rawData)
if err := s.ParseObject(rawData, &jsonParsed); err != nil {
log.Error("Parse object failed: ", err)
return nil, err
}
log.Debug("Parsed object list: ", jsonParsed)
// Treat JSON as a list and then apply the data path
if s.isTargetList {
// Get all values
asList := s.GetSubObjectFromList(&jsonParsed)
log.Debug("Host list:", asList)
hostlist.Set(*asList)
return hostlist, nil
}
// Get the top value
list := s.GetSubObjectFromList(&jsonParsed)
var host string
for _, v := range *list {
host = v
break
}
hostlist.Set([]string{host})
return hostlist, nil
}
// It's an object
s.ParseObject(rawData, &jsonParsed)
if s.isTargetList {
// It's a list object
log.Debug("It's a target list - getting sub object from list")
log.Debug("Passing in: ", jsonParsed)
asList := s.GetSubObjectFromList(&jsonParsed)
hostlist.Set(*asList)
log.Debug("Got from object: ", hostlist)
return hostlist, nil
}
// It's a single object
host := s.GetSubObject(&jsonParsed)
hostlist.Set([]string{host})
return hostlist, nil
}
// TykNewSingleHostReverseProxy returns a new ReverseProxy that rewrites
// URLs to the scheme, host, and base path provided in target. If the
// target's path is "/base" and the incoming request was for "/dir",
// the target request will be for /base/dir. This version modifies the
// stdlib version by also setting the host to the target, this allows
// us to work with heroku and other such providers
func TykNewSingleHostReverseProxy(target *url.URL, spec *APISpec) *ReverseProxy {
// initalise round robin
spec.RoundRobin = &RoundRobin{}
spec.RoundRobin.SetMax(tykcommon.NewHostList())
if spec.Proxy.ServiceDiscovery.UseDiscoveryService {
log.Debug("[PROXY] Service discovery enabled")
if ServiceCache == nil {
log.Debug("[PROXY] Service cache initialising")
expiry := 120
if config.ServiceDiscovery.DefaultCacheTimeout > 0 {
expiry = config.ServiceDiscovery.DefaultCacheTimeout
}
ServiceCache = cache.New(time.Duration(expiry)*time.Second, 15*time.Second)
}
}
targetQuery := target.RawQuery
director := func(req *http.Request) {
var targetSet bool
if spec.Proxy.ServiceDiscovery.UseDiscoveryService {
tempTargetURL, tErr := GetURLFromService(spec)
if tErr != nil {
log.Error("[PROXY] [SERVICE DISCOVERY] Failed target lookup: ", tErr)
} else {
// No error, replace the target
if spec.Proxy.EnableLoadBalancing {
remote, err := url.Parse(GetNextTarget(tempTargetURL, spec, 0))
if err != nil {
log.Error("[PROXY] [SERVICE DISCOVERY] Couldn't parse target URL:", err)
} else {
// Only replace target if everything is OK
target = remote
targetQuery = target.RawQuery
}
} else {
remote, err := url.Parse(GetNextTarget(tempTargetURL, spec, 0))
if err != nil {
log.Error("[PROXY] [SERVICE DISCOVERY] Couldn't parse target URL:", err)
} else {
// Only replace target if everything is OK
target = remote
targetQuery = target.RawQuery
}
}
}
// We've overriden remote now, don;t need to do it again
targetSet = true
}
if !targetSet {
// no override, better check if LB is enabled
if spec.Proxy.EnableLoadBalancing {
// it is, lets get that target data
lbRemote, lbErr := url.Parse(GetNextTarget(spec.Proxy.StructuredTargetList, spec, 0))
if lbErr != nil {
log.Error("[PROXY] [LOAD BALANCING] Couldn't parse target URL:", lbErr)
} else {
// Only replace target if everything is OK
target = lbRemote
targetQuery = target.RawQuery
}
}
}
// Specifically override with a URL rewrite
var newTarget *url.URL
switchTargets := false
if spec.URLRewriteEnabled {
URLRewriteContainsTarget, found := context.GetOk(req, RetainHost)
if found {
if URLRewriteContainsTarget.(bool) {
log.Debug("Detected host rewrite, overriding target")
tmpTarget, pErr := url.Parse(req.URL.String())
if pErr != nil {
log.Error("Failed to parse URL! Err: ", pErr)
} else {
newTarget = tmpTarget
switchTargets = true
}
context.Clear(req)
}
}
}
// No override, and no load balancing? Use the existing target
targetToUse := target
if switchTargets {
targetToUse = newTarget
}
req.URL.Scheme = targetToUse.Scheme
req.URL.Host = targetToUse.Host
req.URL.Path = singleJoiningSlash(targetToUse.Path, req.URL.Path)
if !spec.Proxy.PreserveHostHeader {
req.Host = targetToUse.Host
}
if targetQuery == "" || req.URL.RawQuery == "" {
req.URL.RawQuery = targetQuery + req.URL.RawQuery
} else {
req.URL.RawQuery = targetQuery + "&" + req.URL.RawQuery
}
}
return &ReverseProxy{Director: director, TykAPISpec: spec, FlushInterval: time.Duration(config.HttpServerOptions.FlushInterval) * time.Millisecond}
}