hs-test: experimental support for multiple test instances

- appending PID to interface and container names
- added a check for used IP addresses
- TestEnvoyProxyHttpTcp and TestTcpWithLoss are broken when running multiple instances

Type: test

Change-Id: Ib917079ec7cf851dee59ff9c67e74f48c7c5e3c6
Signed-off-by: adrianvillin <avillin@cisco.com>

1 files changed, 58 insertions, 2 deletions

diff --git a/extras/hs-test/address_allocator.go b/extras/hs-test/address_allocator.go
index c08f88958dc..72bc298fd3f 100644
--- a/extras/hs-test/address_allocator.go
+++ b/extras/hs-test/address_allocator.go
@@ -1,11 +1,20 @@
 package main
 
-import "fmt"
+import (
+	"errors"
+	"fmt"
+	"os"
+	"strings"
+
+	"github.com/edwarnicke/exechelper"
+)
 
 type AddressCounter = int
 
 type Ip4AddressAllocator struct {
 	networks map[int]AddressCounter
+	chosenOctet int
+	assignedIps []string
 }
 
 func (a *Ip4AddressAllocator) AddNetwork(networkNumber int) {
@@ -28,12 +37,59 @@ func (a *Ip4AddressAllocator) NewIp4InterfaceAddress(inputNetworkNumber ...int)
 		return "", fmt.Errorf("no available IPv4 addresses")
 	}
 
-	address := fmt.Sprintf("10.10.%v.%v/24", networkNumber, numberOfAddresses)
+	address, err := a.createIpAddress(networkNumber, numberOfAddresses)
+
 	a.networks[networkNumber] = numberOfAddresses + 1
 
+	return address + "/24", err
+}
+
+// Creates a file every time an IP is assigned: used to keep track of addresses in use.
+// If an address is not in use, 'counter' is then copied to 'chosenOctet' and it is used for the remaining tests.
+// Also checks host IP addresses.
+func (a *Ip4AddressAllocator) createIpAddress(networkNumber int, numberOfAddresses int) (string, error){
+	hostIps, _ := exechelper.CombinedOutput("ip a")
+	counter := 10
+	var address string
+
+	for {
+		if a.chosenOctet != 0 {
+			address = fmt.Sprintf("10.%v.%v.%v", a.chosenOctet, networkNumber, numberOfAddresses)
+			file, err := os.Create(address)
+			if err != nil{
+				return "", errors.New("unable to create file: " + fmt.Sprint(err))
+			}
+			file.Close()
+			break
+		} else {
+			address = fmt.Sprintf("10.%v.%v.%v", counter, networkNumber, numberOfAddresses)
+			_, err := os.Stat(address)
+			if err == nil || strings.Contains(string(hostIps), address) {
+				counter++
+			} else if os.IsNotExist(err) {
+				file, err := os.Create(address)
+					if err != nil{
+					return "", errors.New("unable to create file: " + fmt.Sprint(err))
+					}
+				file.Close()
+				a.chosenOctet = counter
+				break
+			} else {
+				return "", errors.New("an error occured while checking if a file exists: " + fmt.Sprint(err))
+			}
+		}
+	}
+
+	a.assignedIps = append(a.assignedIps, address)
 	return address, nil
 }
 
+func (a *Ip4AddressAllocator) deleteIpAddresses(){
+	for ip := range a.assignedIps{
+		os.Remove(a.assignedIps[ip])
+	}
+}
+
 func NewIp4AddressAllocator() *Ip4AddressAllocator {
 	var ip4AddrAllocator = new(Ip4AddressAllocator)
 	ip4AddrAllocator.networks = make(map[int]AddressCounter)