nodepool: set instance hostname via sudo

Grant passwordless sudo to the jenkins user.
Setup hostname
Get rid of sudo rule via the ready script.

Later on we will run puppet as well to have the instance fully ready.

Bug: T111377
Change-Id: I9aaa5900c6367216b17efd95e587c343ceb78497

dib/build_image.sh

@@ -31,8 +31,11 @@ export DIB_IMAGE_NAME=${DIB_IMAGE_NAME:-"image-${DIB_RELEASE}-${DATE}"}
 export IMAGE_TYPE="qcow2"
 
 export DIB_CLOUD_INIT_DATASOURCES='Ec2'
+
+# sudo rule is removed by /nodepool/scripts/ready.sh
 export DIB_DEV_USER_USERNAME='jenkins'
 export DIB_DEV_USER_AUTHORIZED_KEYS='dib_jenkins_id_rsa.pub'
+export DIB_DEV_USER_PWDLESS_SUDO='yes'
 
 export QEMU_IMG_OPTIONS='compat=0.10'  # XXX might not be needed
 

nodepool/scripts/ready.sh

@@ -0,0 +1,10 @@
+#!/bin/bash
+
+set -e
+set -u
+set -x
+set -o pipefail
+
+
+# Get rid of jenkins sudo
+rm -fv /etc/sudoers.d/jenkins

nodepool/scripts/setup_node.sh

@@ -9,5 +9,6 @@ fi;
 set -u
 
 HOSTNAME="$1"
-echo "Placeholder Nodepool setup script"
-echo "Hostname: $1"
+echo "Hostname: $HOSTNAME"
+sudo hostname $HOSTNAME
+echo "127.0.0.1 $HOSTNAME" >> /etc/hosts