New standard GO project layout

[ric-plt/appmgr.git] / cmd / appmgr / subscriptions.go

diff --git a/cmd/appmgr/subscriptions.go b/cmd/appmgr/subscriptions.go
new file mode 100755 (executable)
index 0000000..5728e5b
--- /dev/null
+++ b/cmd/appmgr/subscriptions.go
@@ -0,0 +1,149 @@
+/*
+==================================================================================
+  Copyright (c) 2019 AT&T Intellectual Property.
+  Copyright (c) 2019 Nokia
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================================
+*/
+
+package main
+
+import (
+       "bytes"
+       "encoding/json"
+       "fmt"
+       "github.com/segmentio/ksuid"
+       "net/http"
+       "time"
+)
+
+func (sd *SubscriptionDispatcher) Initialize() {
+       sd.client = &http.Client{}
+
+       sd.db = &DB{}
+       sd.db.Create()
+       sd.subscriptions = sd.db.RestoreSubscriptions()
+}
+
+func (sd *SubscriptionDispatcher) Add(sr SubscriptionReq) (resp SubscriptionResp) {
+       key := ksuid.New().String()
+       resp = SubscriptionResp{key, 0, sr.EventType}
+       sr.Id = key
+
+       sd.subscriptions.Set(key, Subscription{sr, resp})
+       sd.db.StoreSubscriptions(sd.subscriptions)
+
+       mdclog(MdclogInfo, fmt.Sprintf("Sub: New subscription added: key=%s value=%v", key, sr))
+       return
+}
+
+func (sd *SubscriptionDispatcher) GetAll() (hooks []SubscriptionReq) {
+       hooks = []SubscriptionReq{}
+       for v := range sd.subscriptions.IterBuffered() {
+               hooks = append(hooks, v.Val.(Subscription).req)
+       }
+
+       return hooks
+}
+
+func (sd *SubscriptionDispatcher) Get(id string) (SubscriptionReq, bool) {
+       if v, found := sd.subscriptions.Get(id); found {
+               mdclog(MdclogInfo, fmt.Sprintf("Subscription id=%s found: %v", id, v.(Subscription).req))
+
+               return v.(Subscription).req, found
+       }
+       return SubscriptionReq{}, false
+}
+
+func (sd *SubscriptionDispatcher) Delete(id string) (SubscriptionReq, bool) {
+       if v, found := sd.subscriptions.Get(id); found {
+               mdclog(MdclogInfo, fmt.Sprintf("Subscription id=%s found: %v ... deleting", id, v.(Subscription).req))
+
+               sd.subscriptions.Remove(id)
+               sd.db.StoreSubscriptions(sd.subscriptions)
+
+               return v.(Subscription).req, found
+       }
+       return SubscriptionReq{}, false
+}
+
+func (sd *SubscriptionDispatcher) Update(id string, sr SubscriptionReq) (SubscriptionReq, bool) {
+       if s, found := sd.subscriptions.Get(id); found {
+               mdclog(MdclogInfo, fmt.Sprintf("Subscription id=%s found: %v ... updating", id, s.(Subscription).req))
+
+               sr.Id = id
+               sd.subscriptions.Set(id, Subscription{sr, s.(Subscription).resp})
+               sd.db.StoreSubscriptions(sd.subscriptions)
+
+               return sr, found
+       }
+       return SubscriptionReq{}, false
+}
+
+func (sd *SubscriptionDispatcher) Publish(x Xapp, et EventType) {
+       sd.notifyClients([]Xapp{x}, et)
+}
+
+func (sd *SubscriptionDispatcher) notifyClients(xapps []Xapp, et EventType) {
+       if len(xapps) == 0 || len(sd.subscriptions) == 0 {
+               mdclog(MdclogInfo, fmt.Sprintf("Nothing to publish [%d:%d]", len(xapps), len(sd.subscriptions)))
+               return
+       }
+
+       sd.Seq = sd.Seq + 1
+       for v := range sd.subscriptions.Iter() {
+               go sd.notify(xapps, et, v.Val.(Subscription), sd.Seq)
+       }
+}
+
+func (sd *SubscriptionDispatcher) notify(xapps []Xapp, et EventType, s Subscription, seq int) error {
+       notif := []SubscriptionNotif{}
+       notif = append(notif, SubscriptionNotif{Id: s.req.Id, Version: seq, EventType: string(et), XappData: xapps})
+
+       jsonData, err := json.Marshal(notif)
+       if err != nil {
+               mdclog(MdclogInfo, fmt.Sprintf("json.Marshal failed: %v", err))
+               return err
+       }
+
+       // Execute the request with retry policy
+       return sd.retry(s, func() error {
+               resp, err := http.Post(s.req.TargetUrl, "application/json", bytes.NewBuffer(jsonData))
+               if err != nil {
+                       mdclog(MdclogInfo, fmt.Sprintf("Posting to subscription failed: %v", err))
+                       return err
+               }
+
+               if resp.StatusCode != http.StatusOK {
+                       mdclog(MdclogInfo, fmt.Sprintf("Client returned error code: %d", resp.StatusCode))
+                       return err
+               }
+
+               mdclog(MdclogInfo, fmt.Sprintf("subscription to '%s' dispatched, response code: %d \n", s.req.TargetUrl, resp.StatusCode))
+               return nil
+       })
+}
+
+func (sd *SubscriptionDispatcher) retry(s Subscription, fn func() error) error {
+       if err := fn(); err != nil {
+               // Todo: use exponential backoff, or similar mechanism
+               if s.req.MaxRetries--; s.req.MaxRetries > 0 {
+                       time.Sleep(time.Duration(s.req.RetryTimer) * time.Second)
+                       return sd.retry(s, fn)
+               }
+               sd.subscriptions.Remove(s.req.Id)
+               return err
+       }
+       return nil
+}