From e5a9976a936311ad2cc21ae8615043cd5f2f21b5 Mon Sep 17 00:00:00 2001
From: liwen wu <liwenwu@amazon.com>
Date: Tue, 15 May 2018 18:49:55 +0000
Subject: [PATCH] Add config option for number of ENIs get preallocated

---
 ipamd/ipamd.go               | 40 +++++++++++++++++++++++++++++-------
 misc/cni_metrics_helper.yaml |  5 ++++-
 2 files changed, 37 insertions(+), 8 deletions(-)

diff --git a/ipamd/ipamd.go b/ipamd/ipamd.go
index e15f30c285a..336b9b75265 100644
--- a/ipamd/ipamd.go
+++ b/ipamd/ipamd.go
@@ -15,6 +15,8 @@ package ipamd
 
 import (
 	"net"
+	"os"
+	"strconv"
 	"strings"
 	"time"
 
@@ -40,6 +42,7 @@ const (
 	ipPoolMonitorInterval = 5 * time.Second
 	maxRetryCheckENI      = 5
 	eniAttachTime         = 10 * time.Second
+	defaultPreAllocENIs   = 1
 )
 
 var (
@@ -117,6 +120,8 @@ func New() (*IPAMContext, error) {
 
 //TODO need to break this function down(comments from CR)
 func (c *IPAMContext) nodeInit() error {
+	ipamdActionsInprogress.WithLabelValues("nodeInit").Add(float64(1))
+	defer ipamdActionsInprogress.WithLabelValues("nodeInit").Sub(float64(1))
 	maxENIs, err := c.awsClient.GetENILimit()
 	enisMax.Set(float64(maxENIs))
 	enis, err := c.awsClient.GetAttachedENIs()
@@ -260,6 +265,10 @@ func (c *IPAMContext) increaseIPPool() {
 		return
 	}
 	if (c.maxENI > 0) && (c.maxENI == c.dataStore.GetENIs()) {
+		if c.maxENI < maxENIs {
+			errString := "desired: " + strconv.FormatInt(int64(maxENIs), 10) + "current: " + strconv.FormatInt(int64(c.maxENI), 10)
+			ipamdErrInc("unExpectedMaxENIAttached", errors.New(errString))
+		}
 		log.Debugf("Skipping increase IPPOOL due to max ENI already attached to the instance : %d", c.maxENI)
 		return
 	}
@@ -400,23 +409,40 @@ func (c *IPAMContext) waitENIAttached(eni string) (awsutils.ENIMetadata, error)
 	}
 }
 
+func getPreAllocENILimit() int {
+	limitStr, found := os.LookupEnv("PRE_ALLOC_ENIS")
+
+	if !found {
+		return defaultPreAllocENIs
+	}
+
+	if limit, err := strconv.Atoi(limitStr); err == nil {
+		if limit < 0 {
+			return defaultPreAllocENIs
+		}
+		return limit
+	}
+	return defaultPreAllocENIs
+}
+
 //nodeIPPoolTooLow returns true if IP pool is below low threshhold
 func (c *IPAMContext) nodeIPPoolTooLow() bool {
+	preAllocENIs := getPreAllocENILimit()
 	total, used := c.dataStore.GetStats()
-	log.Debugf("IP pool stats: total=%d, used=%d, c.currentMaxAddrsPerENI =%d, c.maxAddrsPerENI = %d",
-		total, used, c.currentMaxAddrsPerENI, c.maxAddrsPerENI)
+	log.Debugf("IP pool stats: total=%d, used=%d, c.currentMaxAddrsPerENI =%d, c.maxAddrsPerENI = %d, preAllocENIs = %d",
+		total, used, c.currentMaxAddrsPerENI, c.maxAddrsPerENI, preAllocENIs)
 
-	return ((total - used) <= c.currentMaxAddrsPerENI)
+	return ((total - used) <= c.currentMaxAddrsPerENI*preAllocENIs)
 }
 
 // NodeIPPoolTooHigh returns true if IP pool is above high threshhold
 func (c *IPAMContext) nodeIPPoolTooHigh() bool {
+	preAllocENIs := getPreAllocENILimit()
 	total, used := c.dataStore.GetStats()
+	log.Debugf("IP pool stats: total=%d, used=%d, c.currentMaxAddrsPerENI =%d, c.maxAddrsPerENI = %d, preAllocENIs",
+		total, used, c.currentMaxAddrsPerENI, c.maxAddrsPerENI, preAllocENIs)
 
-	log.Debugf("IP pool stats: total=%d, used=%d, c.currentMaxAddrsPerENI =%d, c.maxAddrsPerENI = %d",
-		total, used, c.currentMaxAddrsPerENI, c.maxAddrsPerENI)
-
-	return (total-used > 2*c.currentMaxAddrsPerENI)
+	return (total-used > (preAllocENIs+1)*c.currentMaxAddrsPerENI)
 
 }
 
diff --git a/misc/cni_metrics_helper.yaml b/misc/cni_metrics_helper.yaml
index e0c21fd1074..05fdcff4ef9 100644
--- a/misc/cni_metrics_helper.yaml
+++ b/misc/cni_metrics_helper.yaml
@@ -77,6 +77,9 @@ spec:
     spec:
       serviceAccountName: cni-metrics-helper
       containers:
-      - image: 694065802095.dkr.ecr.us-west-2.amazonaws.com/cni-metrics-helper:0.1.0
+      - image: 694065802095.dkr.ecr.us-west-2.amazonaws.com/cni-metrics-helper:0.1.1
         imagePullPolicy: Always
         name: cni-metrics-helper
+        env:
+          - name: USE_CLOUDWATCH
+            value: "no"