fix sshprivatekey validation and testinfra exec failure

Author: mschuchard

CHANGELOG.md

@@ -2,6 +2,8 @@
 - Note in Packer logs when they originate from this plugin.
 - Promote `winrm` to officially supported communicator.
 - Minor code optimization.
+- Fix Packer ssh private key validation.
+- Indicate failed testinfra execution based solely on exit code.
 
 ### 1.5.1
 - More improvements to Packer communicators' settings interfacing with Testinfra provisioner plugin.

provisioner/command.go

@@ -113,7 +113,7 @@ func packerRemoteCmd(localCmd *packer.RemoteCmd, installCmd []string, comm packe
 
 	// wait for testinfra to complete and flush buffers
 	// then check for pytest/testinfra execution issues
-	if exitStatus := localCmd.Wait(); exitStatus > 0 || len(stderr.String()) > 0 {
+	if exitStatus := localCmd.Wait(); exitStatus > 0 {
 		ui.Error("Testinfra errored internally during execution:")
 		ui.Error(stderr.String())
 		ui.Errorf("Testinfra returned exit status: %d", exitStatus)

provisioner/communication.go

@@ -241,7 +241,7 @@ func (provisioner *Provisioner) determineSSHAuth(ui packer.Ui) (sshAuth, string,
 		} else { // we have no other options, so create a temp private key file from the packer data
 			// attempt to obtain a private key
 			SSHPrivateKey, ok := provisioner.generatedData["SSHPrivateKey"].(string)
-			if !ok || len("SSHPrivateKey") == 0 {
+			if !ok || len(SSHPrivateKey) == 0 {
 				ui.Error("no SSH authentication information was available in Packer data")
 				return "", "", errors.New("no ssh authentication")
 			}