improve error handling in deploy_admin_ws.sh (#79)

improve error handling in deploy_admin_ws.sh
* major commands are printed to stderr before running.
* and will exit if on failure
* minor refactoring of complex pipelines

anthos/deploy_admin_ws.sh

@@ -1,5 +1,35 @@
 #!/bin/bash
 
+# print a message to stderr, prefixed by the hostname
+function note() {
+  echo 1>&2 "$(hostname): $*"
+}
+
+# print the given command to stderr, run it, and exit verbosely if it fails.
+function xrun() {
+  vrun "$@" && return 0
+
+  local xstat=$?
+  note "Cmd $1 failed, exit $xstat"
+  exit "$xstat"
+}
+
+# print the given command to stderr, run it.  return the status
+function vrun() {
+  note "+ $@"
+  "$@"
+}
+
+# fetch the vcenter pem from the givem host:port, and print it to stdout.
+function fetch_pem() {
+  local addr=$1
+  xrun openssl s_client -showcerts -verify 5 -connect "$addr" < /dev/null \
+  | awk '/BEGIN/,/END/ {print}'
+  return "$((PIPESTATUS[0]))"
+}
+
+# ----- statt of mainline code
+
 export WORKSTATIONIP=__IP_ADDRESS__
 
 if [ -f "/root/anthos/gkeadm" ] ; then
@@ -8,14 +38,16 @@ if [ -f "/root/anthos/gkeadm" ] ; then
   echo "** Errors in the following section related to enabling APIs and creating **"
   echo "** IAM roles are expected and can safely be ignored                      **"
   echo "***********************#***************************************************"
-  openssl s_client -showcerts -verify 5 -connect ${vcenter_fqdn}:443 < /dev/null | awk '/BEGIN/,/END/{ if(/BEGIN/){a++}; out="/root/anthos/vspherecert.pem"; print >out}'
-  /root/anthos/gkeadm create admin-workstation --config /root/anthos/admin-ws-config.yaml --ssh-key-path /root/anthos/ssh_key --skip-validation
+  fetch_pem ${vcenter_fqdn}:443 > /root/anthos/vspherecert.pem || exit 1
+  vrun /root/anthos/gkeadm create admin-workstation --config /root/anthos/admin-ws-config.yaml --ssh-key-path /root/anthos/ssh_key --skip-validation
   echo "*************************************************************************"
   echo "** Errors in the above section related to enabling APIs and creating   **"
   echo "** IAM roles are expected and can safely be ignored                    **"
   echo "*************************************************************************"
 else
   echo "Deploying Admin Workstation with terraform"
-  terraform init
-  terraform apply --auto-approve
+  xrun terraform init
+  xrun terraform apply --auto-approve
 fi
+
+note "# succeeded"