[VOL-2193] Create mocks for Kafka Client and Etcd
This commit consists of:
1) A kafka client mock that implements the kafka client interface
under voltha-lib-go/pkg/kafka/client.go
2) An embedded Etcd server that runs in-process and represents an
Etcd server.
Change-Id: I52a36132568e08c596bb4136918bebcb654a3b99
diff --git a/vendor/github.com/xiang90/probing/.gitignore b/vendor/github.com/xiang90/probing/.gitignore
new file mode 100644
index 0000000..daf913b
--- /dev/null
+++ b/vendor/github.com/xiang90/probing/.gitignore
@@ -0,0 +1,24 @@
+# Compiled Object files, Static and Dynamic libs (Shared Objects)
+*.o
+*.a
+*.so
+
+# Folders
+_obj
+_test
+
+# Architecture specific extensions/prefixes
+*.[568vq]
+[568vq].out
+
+*.cgo1.go
+*.cgo2.c
+_cgo_defun.c
+_cgo_gotypes.go
+_cgo_export.*
+
+_testmain.go
+
+*.exe
+*.test
+*.prof
diff --git a/vendor/github.com/xiang90/probing/LICENSE b/vendor/github.com/xiang90/probing/LICENSE
new file mode 100644
index 0000000..cde8b8b
--- /dev/null
+++ b/vendor/github.com/xiang90/probing/LICENSE
@@ -0,0 +1,22 @@
+The MIT License (MIT)
+
+Copyright (c) 2015 Xiang Li
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+
diff --git a/vendor/github.com/xiang90/probing/README.md b/vendor/github.com/xiang90/probing/README.md
new file mode 100644
index 0000000..2ff6820
--- /dev/null
+++ b/vendor/github.com/xiang90/probing/README.md
@@ -0,0 +1,39 @@
+## Getting Started
+
+### Install the handler
+
+We first need to serve the probing HTTP handler.
+
+```go
+ http.HandleFunc("/health", probing.NewHandler())
+ err := http.ListenAndServe(":12345", nil)
+ if err != nil {
+ log.Fatal("ListenAndServe: ", err)
+ }
+```
+
+### Start to probe
+
+Now we can start to probe the endpoint.
+
+``` go
+ id := "example"
+ probingInterval = 5 * time.Second
+ url := "http://example.com:12345/health"
+ p.AddHTTP(id, probingInterval, url)
+
+ time.Sleep(13 * time.Second)
+ status, err := p.Status(id)
+ fmt.Printf("Total Probing: %d, Total Loss: %d, Estimated RTT: %v, Estimated Clock Difference: %v\n",
+ status.Total(), status.Loss(), status.SRTT(), status.ClockDiff())
+ // Total Probing: 2, Total Loss: 0, Estimated RTT: 320.771µs, Estimated Clock Difference: -35.869µs
+```
+
+### TODOs:
+
+- TCP probing
+- UDP probing
+- Gossip based probing
+- More accurate RTT estimation
+- More accurate Clock difference estimation
+- Use a clock interface rather than the real clock
diff --git a/vendor/github.com/xiang90/probing/prober.go b/vendor/github.com/xiang90/probing/prober.go
new file mode 100644
index 0000000..9431c10
--- /dev/null
+++ b/vendor/github.com/xiang90/probing/prober.go
@@ -0,0 +1,139 @@
+package probing
+
+import (
+ "encoding/json"
+ "errors"
+ "fmt"
+ "net/http"
+ "sync"
+ "time"
+)
+
+var (
+ ErrNotFound = errors.New("probing: id not found")
+ ErrExist = errors.New("probing: id exists")
+)
+
+type Prober interface {
+ AddHTTP(id string, probingInterval time.Duration, endpoints []string) error
+ Remove(id string) error
+ RemoveAll()
+ Reset(id string) error
+ Status(id string) (Status, error)
+}
+
+type prober struct {
+ mu sync.Mutex
+ targets map[string]*status
+ tr http.RoundTripper
+}
+
+func NewProber(tr http.RoundTripper) Prober {
+ p := &prober{targets: make(map[string]*status)}
+ if tr == nil {
+ p.tr = http.DefaultTransport
+ } else {
+ p.tr = tr
+ }
+ return p
+}
+
+func (p *prober) AddHTTP(id string, probingInterval time.Duration, endpoints []string) error {
+ p.mu.Lock()
+ defer p.mu.Unlock()
+ if _, ok := p.targets[id]; ok {
+ return ErrExist
+ }
+
+ s := &status{stopC: make(chan struct{})}
+ p.targets[id] = s
+
+ ticker := time.NewTicker(probingInterval)
+
+ go func() {
+ pinned := 0
+ for {
+ select {
+ case <-ticker.C:
+ start := time.Now()
+ req, err := http.NewRequest("GET", endpoints[pinned], nil)
+ if err != nil {
+ panic(err)
+ }
+ resp, err := p.tr.RoundTrip(req)
+ if err == nil && resp.StatusCode != http.StatusOK {
+ err = fmt.Errorf("got unexpected HTTP status code %s from %s", resp.Status, endpoints[pinned])
+ resp.Body.Close()
+ }
+ if err != nil {
+ s.recordFailure(err)
+ pinned = (pinned + 1) % len(endpoints)
+ continue
+ }
+
+ var hh Health
+ d := json.NewDecoder(resp.Body)
+ err = d.Decode(&hh)
+ resp.Body.Close()
+ if err != nil || !hh.OK {
+ s.recordFailure(err)
+ pinned = (pinned + 1) % len(endpoints)
+ continue
+ }
+
+ s.record(time.Since(start), hh.Now)
+ case <-s.stopC:
+ ticker.Stop()
+ return
+ }
+ }
+ }()
+
+ return nil
+}
+
+func (p *prober) Remove(id string) error {
+ p.mu.Lock()
+ defer p.mu.Unlock()
+
+ s, ok := p.targets[id]
+ if !ok {
+ return ErrNotFound
+ }
+ close(s.stopC)
+ delete(p.targets, id)
+ return nil
+}
+
+func (p *prober) RemoveAll() {
+ p.mu.Lock()
+ defer p.mu.Unlock()
+
+ for _, s := range p.targets {
+ close(s.stopC)
+ }
+ p.targets = make(map[string]*status)
+}
+
+func (p *prober) Reset(id string) error {
+ p.mu.Lock()
+ defer p.mu.Unlock()
+
+ s, ok := p.targets[id]
+ if !ok {
+ return ErrNotFound
+ }
+ s.reset()
+ return nil
+}
+
+func (p *prober) Status(id string) (Status, error) {
+ p.mu.Lock()
+ defer p.mu.Unlock()
+
+ s, ok := p.targets[id]
+ if !ok {
+ return nil, ErrNotFound
+ }
+ return s, nil
+}
diff --git a/vendor/github.com/xiang90/probing/server.go b/vendor/github.com/xiang90/probing/server.go
new file mode 100644
index 0000000..0e7b797
--- /dev/null
+++ b/vendor/github.com/xiang90/probing/server.go
@@ -0,0 +1,25 @@
+package probing
+
+import (
+ "encoding/json"
+ "net/http"
+ "time"
+)
+
+func NewHandler() http.Handler {
+ return &httpHealth{}
+}
+
+type httpHealth struct {
+}
+
+type Health struct {
+ OK bool
+ Now time.Time
+}
+
+func (h *httpHealth) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+ health := Health{OK: true, Now: time.Now()}
+ e := json.NewEncoder(w)
+ e.Encode(health)
+}
diff --git a/vendor/github.com/xiang90/probing/status.go b/vendor/github.com/xiang90/probing/status.go
new file mode 100644
index 0000000..bb5f659
--- /dev/null
+++ b/vendor/github.com/xiang90/probing/status.go
@@ -0,0 +1,108 @@
+package probing
+
+import (
+ "sync"
+ "time"
+)
+
+var (
+ // weight factor
+ α = 0.125
+)
+
+type Status interface {
+ Total() int64
+ Loss() int64
+ Health() bool
+ Err() error
+ // Estimated smoothed round trip time
+ SRTT() time.Duration
+ // Estimated clock difference
+ ClockDiff() time.Duration
+ StopNotify() <-chan struct{}
+}
+
+type status struct {
+ mu sync.Mutex
+ srtt time.Duration
+ total int64
+ loss int64
+ health bool
+ err error
+ clockdiff time.Duration
+ stopC chan struct{}
+}
+
+// SRTT = (1-α) * SRTT + α * RTT
+func (s *status) SRTT() time.Duration {
+ s.mu.Lock()
+ defer s.mu.Unlock()
+ return s.srtt
+}
+
+func (s *status) Total() int64 {
+ s.mu.Lock()
+ defer s.mu.Unlock()
+ return s.total
+}
+
+func (s *status) Loss() int64 {
+ s.mu.Lock()
+ defer s.mu.Unlock()
+ return s.loss
+}
+
+func (s *status) Health() bool {
+ s.mu.Lock()
+ defer s.mu.Unlock()
+ return s.health
+}
+
+func (s *status) Err() error {
+ s.mu.Lock()
+ defer s.mu.Unlock()
+ return s.err
+}
+
+func (s *status) ClockDiff() time.Duration {
+ s.mu.Lock()
+ defer s.mu.Unlock()
+ return s.clockdiff
+}
+
+func (s *status) StopNotify() <-chan struct{} {
+ return s.stopC
+}
+
+func (s *status) record(rtt time.Duration, when time.Time) {
+ s.mu.Lock()
+ defer s.mu.Unlock()
+
+ s.total += 1
+ s.health = true
+ s.srtt = time.Duration((1-α)*float64(s.srtt) + α*float64(rtt))
+ s.clockdiff = time.Now().Sub(when) - s.srtt/2
+ s.err = nil
+}
+
+func (s *status) recordFailure(err error) {
+ s.mu.Lock()
+ defer s.mu.Unlock()
+
+ s.total++
+ s.health = false
+ s.loss += 1
+ s.err = err
+}
+
+func (s *status) reset() {
+ s.mu.Lock()
+ defer s.mu.Unlock()
+
+ s.srtt = 0
+ s.total = 0
+ s.loss = 0
+ s.health = false
+ s.clockdiff = 0
+ s.err = nil
+}