From c211ba0d07ef5c4e1a881767b41b85d0984cd12d Mon Sep 17 00:00:00 2001
From: Alex <alexellis2@gmail.com>
Date: Mon, 30 Jan 2017 21:16:54 +0000
Subject: [PATCH] Cover replica scaling with tests.
---
gateway/handlers/alerthandler.go | 49 ++++++++++++++++--------------
gateway/tests/alerthandler_test.go | 47 ++++++++++++++++++++++++++++
gateway/tests/isalexa_test.go | 27 ----------------
3 files changed, 74 insertions(+), 49 deletions(-)
create mode 100644 gateway/tests/alerthandler_test.go
delete mode 100644 gateway/tests/isalexa_test.go
diff --git a/gateway/handlers/alerthandler.go b/gateway/handlers/alerthandler.go
index 0017954b..10d0271a 100644
--- a/gateway/handlers/alerthandler.go
+++ b/gateway/handlers/alerthandler.go
@@ -12,38 +12,43 @@ import (
"github.com/docker/docker/client"
)
+// CalculateReplicas decides what replica count to set depending on a Prometheus alert
+func CalculateReplicas(status string, currentReplicas uint64) uint64 {
+ newReplicas := currentReplicas
+
+ if status == "firing" {
+ if currentReplicas == 1 {
+ newReplicas = 5
+ } else {
+ if currentReplicas+5 > 20 {
+ newReplicas = 20
+ } else {
+ newReplicas = currentReplicas + 5
+ }
+ }
+ } else { // Resolved event.
+ newReplicas = 1
+ }
+ return newReplicas
+}
+
func scaleService(req requests.PrometheusAlert, c *client.Client) error {
var err error
//Todo: convert to loop / handler.
serviceName := req.Alerts[0].Labels.FunctionName
service, _, inspectErr := c.ServiceInspectWithRaw(context.Background(), serviceName)
if inspectErr == nil {
- var replicas uint64
- if req.Status == "firing" {
- if *service.Spec.Mode.Replicated.Replicas < 20 {
- replicas = *service.Spec.Mode.Replicated.Replicas + uint64(5)
- } else {
- return err
- }
- } else { // Resolved event.
- // Previously decremented by 5, but event only fires once, so set to 1/1.
- if *service.Spec.Mode.Replicated.Replicas > 1 {
- // replicas = *service.Spec.Mode.Replicated.Replicas - uint64(5)
- // if replicas < 1 {
- // replicas = 1
- // }
- // return nil
+ currentReplicas := *service.Spec.Mode.Replicated.Replicas
+ status := req.Status
+ newReplicas := CalculateReplicas(status, currentReplicas)
- replicas = 1
- } else {
- return nil
- }
+ if newReplicas == currentReplicas {
+ return nil
}
- log.Printf("Scaling %s to %d replicas.\n", serviceName, replicas)
-
- service.Spec.Mode.Replicated.Replicas = &replicas
+ log.Printf("Scaling %s to %d replicas.\n", serviceName, newReplicas)
+ service.Spec.Mode.Replicated.Replicas = &newReplicas
updateOpts := types.ServiceUpdateOptions{}
updateOpts.RegistryAuthFrom = types.RegistryAuthFromSpec
diff --git a/gateway/tests/alerthandler_test.go b/gateway/tests/alerthandler_test.go
new file mode 100644
index 00000000..8475be20
--- /dev/null
+++ b/gateway/tests/alerthandler_test.go
@@ -0,0 +1,47 @@
+package tests
+
+import (
+ "testing"
+
+ "github.com/alexellis/faas/gateway/handlers"
+)
+
+func TestScale1to5(t *testing.T) {
+ newReplicas := handlers.CalculateReplicas("firing", 1)
+ if newReplicas != 5 {
+ t.Log("Expected increment in blocks of 5 from 1 to 5")
+ t.Fail()
+ }
+}
+
+func TestScale5to10(t *testing.T) {
+ newReplicas := handlers.CalculateReplicas("firing", 5)
+ if newReplicas != 10 {
+ t.Log("Expected increment in blocks of 5 from 5 to 10")
+ t.Fail()
+ }
+}
+
+func TestScaleCeilingOf20Replicas_Noaction(t *testing.T) {
+ newReplicas := handlers.CalculateReplicas("firing", 20)
+ if newReplicas != 20 {
+ t.Log("Expected ceiling of 20 replicas")
+ t.Fail()
+ }
+}
+
+func TestScaleCeilingOf20Replicas(t *testing.T) {
+ newReplicas := handlers.CalculateReplicas("firing", 19)
+ if newReplicas != 20 {
+ t.Log("Expected ceiling of 20 replicas")
+ t.Fail()
+ }
+}
+
+func TestBackingOff10to1(t *testing.T) {
+ newReplicas := handlers.CalculateReplicas("resolved", 10)
+ if newReplicas != 1 {
+ t.Log("Expected backing off to 1 replica")
+ t.Fail()
+ }
+}
diff --git a/gateway/tests/isalexa_test.go b/gateway/tests/isalexa_test.go
deleted file mode 100644
index 89c86370..00000000
--- a/gateway/tests/isalexa_test.go
+++ /dev/null
@@ -1,27 +0,0 @@
-package tests
-
-import (
- "testing"
-
- "io/ioutil"
-
- "github.com/alexellis/faas/gateway/handlers"
- "github.com/alexellis/faas/gateway/requests"
-)
-
-func TestIsAlexa(t *testing.T) {
- requestBody, _ := ioutil.ReadFile("./alexhostname_request.json")
- var result requests.AlexaRequestBody
-
- result = handlers.IsAlexa(requestBody)
-
- if len(result.Session.Application.ApplicationId) == 0 {
- t.Fail()
- }
- if len(result.Session.SessionId) == 0 {
- t.Fail()
- }
- if len(result.Request.Intent.Name) == 0 {
- t.Fail()
- }
-}
--
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