[windows] [cni] added script to invoke cni with dns as runtime config (#427)

* added script to invoke cni with dns as runtime config

* renamed file

* added usage example

* update script to take dns suffix

* addressed comments

* added comments

* parameterized few variables to make it work for containerd runtime

* updated desc

scripts/invoke_winazurecni.ps1

@@ -0,0 +1,103 @@
+#This script  is to invoke cni for windows containers. It has an option to configure dns related info via cni.
+Param(
+	[parameter(Mandatory=$true)]
+	[string] $containerName,
+
+	[parameter(Mandatory=$true)]
+	[string] $namespace,
+
+	[parameter(Mandatory=$true)]
+	[string] $contid,
+
+	[parameter (Mandatory=$true)]
+	[string] $command,
+
+	[parameter (Mandatory=$false)]
+	[string] $dns,
+
+	[parameter (Mandatory=$false)]
+	[string] $dnssuffix,
+
+	[parameter (Mandatory=$false)]
+	[string] $netns,
+
+	[parameter (Mandatory=$false)]
+	[string] $cnidir,
+
+	[parameter (Mandatory=$false)]
+	[string] $confPath
+)
+
+
+$env:CNI_CONTAINERID=$contid
+$env:CNI_COMMAND=$command
+
+
+$k8sargs='IgnoreUnknown=1;K8S_POD_NAMESPACE={0};K8S_POD_NAME={1};K8S_POD_INFRA_CONTAINER_ID={2}' -f $namespace, $containerName, $contid
+$env:CNI_ARGS=$k8sargs
+$env:CNI_IFNAME='eth0'
+
+if ($netns -eq "") {
+	$netns='none'
+}
+$env:CNI_NETNS=$netns
+
+if ($cnidir -eq "") {
+	$cnidir='C:\k\azurecni\bin'
+}
+$env:CNI_PATH=$cnidir
+$env:PATH="$env:CNI_PATH;"+$env:PATH
+
+if ($confPath -eq "") {
+	$confPath='C:\k\azurecni\netconf\10-azure.conflist'
+}
+
+<#
+usage:
+.\invoke-cni.ps1 <container_name> <namespace> <container_id> [ADD/DEL] <dns_array> <dns_suffix>
+<dns_array> - values should be quoted and comma separated
+<dns_suffix> - values should be quoted and comma separated
+eg: .\cni.ps1 container1 default 01fb3472a90a2ee282b8f15665bd38dc76100922fc7c9c5dd689f578231c9b97 ADD '"1.2.3.4"' '"asd.net"'
+#>
+
+#read conflist and extract plugin component
+
+$content = Get-Content -Raw -Path $confPath
+
+$jobj = ConvertFrom-Json $content
+$plugin=$jobj.plugins[0]
+
+# add name and version in plugin section
+$plugin|add-member -Name "name" -Value $jobj.name -MemberType Noteproperty
+$plugin|add-member -Name "cniVersion" -Value $jobj.cniVersion -MemberType Noteproperty
+
+#remove array datatype as it adds name and value by default
+$arrayDataType = get-TypeData  System.Array
+Remove-TypeData  System.Array
+
+#add dnsserver and dnssuffix(searches) as runtimeconfig parameters
+if ($dns -ne "" -Or $dnssuffix -ne "") {
+	$dnsjson = "[" + $dns + "]"
+	$serverarray = convertfrom-json $dnsjson
+	$configobj = New-Object -TypeName PSObject
+	# add servers array to config object
+	$configobj|add-member -Name "servers" -Value $serverarray -MemberType Noteproperty
+	$dnssuffixjson = "[" + $dnssuffix + "]"
+	$searcharray = convertfrom-json $dnssuffixjson
+	# add searches array to config object
+	$configobj|add-member -Name "searches" -Value $searcharray -MemberType Noteproperty
+
+	# add config object child of dns object
+	$dnsobj = New-Object -TypeName PSObject
+	$dnsobj|add-member -Name "dns" -Value $configobj -MemberType Noteproperty
+
+	# add dns object as child to plugin object
+	$plugin|add-member -Name "runtimeConfig" -Value $dnsobj -MemberType Noteproperty
+}
+
+$jsonconfig=ConvertTo-Json $plugin -Depth 6
+echo $jsonconfig
+$res=(echo $jsonconfig | azure-vnet)
+echo $res
+#restore the array datatype
+Update-TypeData -TypeData $arrayDataType