TT#22415 Retry connect to public GPG keyserver in case of random failures

It looks like public GPG keyservers are not really highly available,
and randomly there are some issues have happens, like:

> gpg: requesting key EF8D349F from hkp server pool.sks-keyservers.net
> ?: [fd 4]: read error: Connection reset by peer
> gpgkeys: HTTP fetch error 7: couldn't connect: eof
> gpg: no valid OpenPGP data found.

Lets add reconnect here, to retry within one minute to hide such kind of issues
which are out of our control..

Change-Id: Ia31488bf0318656fadde1ca8bd43c6c48d5cb5a6

deployment.sh

@@ -1354,9 +1354,16 @@ else
   echo "Fetching debootstrap keyring as GPG key '${GPG_KEY}'..."
   logit "Fetching debootstrap keyring as GPG key '${GPG_KEY}'..."
 
-  if ! gpg --keyserver "${GPG_KEY_SERVER}" --recv-keys "${GPG_KEY}" ; then
-    die "Failed to fetch GPG key '${GPG_KEY}' from '${GPG_KEY_SERVER}'"
-  fi
+  TRY=60
+  while ! gpg --keyserver "${GPG_KEY_SERVER}" --recv-keys "${GPG_KEY}" ; do
+    if [ ${TRY} -gt 0 ] ; then
+      TRY=$((TRY-5))
+      echo "Waiting for gpg keyserver '${GPG_KEY_SERVER}' availability ($TRY seconds)..."
+      sleep 5
+    else
+      die "Failed to fetch GPG key '${GPG_KEY}' from '${GPG_KEY_SERVER}'"
+    fi
+  done
 
   if ! gpg -a --export "${GPG_KEY}" | apt-key add - ; then
     die "Failed to import GPG key '${GPG_KEY}' as apt-key"
@@ -2408,9 +2415,17 @@ deb ${DEBIAN_REPO_TRANSPORT}://${DEBIAN_REPO_HOST}/puppetlabs/ ${DEBIAN_RELEASE}
 EOF
 
   PUPPET_GPG_KEY="6F6B15509CF8E59E6E469F327F438280EF8D349F"
-  if ! chroot ${TARGET} apt-key adv --recv-keys --keyserver "${GPG_KEY_SERVER}" "${PUPPET_GPG_KEY}" ; then
-    die "Failed to fetch GPG key '${PUPPET_GPG_KEY}' from '${GPG_KEY_SERVER}'"
-  fi
+
+  TRY=60
+  while ! chroot ${TARGET} apt-key adv --recv-keys --keyserver "${GPG_KEY_SERVER}" "${PUPPET_GPG_KEY}" ; do
+    if [ ${TRY} -gt 0 ] ; then
+      TRY=$((TRY-5))
+      echo "Waiting for gpg keyserver '${GPG_KEY_SERVER}' availability ($TRY seconds)..."
+      sleep 5
+    else
+      die "Failed to fetch GPG key '${PUPPET_GPG_KEY}' from '${GPG_KEY_SERVER}'"
+    fi
+  done
 
   chroot ${TARGET} apt-get update
   chroot ${TARGET} apt-get -y install puppet-agent openssh-server lsb-release ntpdate