Remove complex retry code and use ServerAliveInterval

remote_access.sh

Index: remote_access.sh
diff --git a/remote_access.sh b/remote_access.sh
index 222fdf7e943399431ffa048a86e0f01d951be3be..70d6058b0242f2f0315f6926ba7e66b1b5af04dc 100644
--- a/remote_access.sh
+++ b/remote_access.sh
@@ -16,7 +16,8 @@ DEFINE_integer ssh_port 22 \
 # Copies $1 to $2 on remote host
 function remote_cp_to() {
   REMOTE_OUT=$(scp -P ${FLAGS_ssh_port} -o StrictHostKeyChecking=no \
-    -o UserKnownHostsFile=$TMP_KNOWN_HOSTS -i $TMP_PRIVATE_KEY $1 \
+    -o ServerAliveInterval=60 -o UserKnownHostsFile=$TMP_KNOWN_HOSTS \
+    -i $TMP_PRIVATE_KEY $1 \
     root@$FLAGS_remote:$2)
   return ${PIPESTATUS[0]}
 }
@@ -25,13 +26,15 @@ function remote_cp_to() {
 # $2.  Directory paths in $1 are collapsed into $2.
 function remote_rsync_from() {
   rsync -e "ssh -p ${FLAGS_ssh_port} -o StrictHostKeyChecking=no \
-             -o UserKnownHostsFile=$TMP_KNOWN_HOSTS -i $TMP_PRIVATE_KEY" \
+             -o ServerAliveInterval=60 -o UserKnownHostsFile=$TMP_KNOWN_HOSTS \
+             -i $TMP_PRIVATE_KEY" \
     --no-R --files-from=$1 root@${FLAGS_remote}:/ $2
 }
 
 function remote_sh() {
   REMOTE_OUT=$(ssh -p ${FLAGS_ssh_port} -o StrictHostKeyChecking=no \
     -o UserKnownHostsFile=$TMP_KNOWN_HOSTS -i $TMP_PRIVATE_KEY \
+    -o ServerAliveInterval=60 \
     root@$FLAGS_remote "$@")
   return ${PIPESTATUS[0]}
 }
@@ -63,29 +66,12 @@ function learn_board() {
   info "Target reports board is ${FLAGS_board}"
 }
 
-# Checks to see if pid $1 is running.
-function is_pid_running() {
-  ps -p ${1} 2>&1 > /dev/null
-}
-
-# Wait function given an additional timeout argument.
-# $1 - pid to wait on.
-# $2 - timeout to wait for.
-function wait_with_timeout() {
-  local pid=$1
-  local timeout=$2
-  local -r TIMEOUT_INC=1
-  local current_timeout=0
-  while is_pid_running ${pid} && [ ${current_timeout} -lt ${timeout} ]; do
-    sleep ${TIMEOUT_INC}
-    current_timeout=$((current_timeout + TIMEOUT_INC))
-  done
-  ! is_pid_running ${pid}
-}
+function remote_reboot {
+  info "Rebooting."
+  remote_sh "touch /tmp/awaiting_reboot; reboot"
+  local output_file
+  output_file="${TMP}/output"
 
-# Checks to see if a machine has rebooted using the presence of a tmp file.
-function check_if_rebooted() {
-  local output_file="${TMP}/output"
   while true; do
     REMOTE_OUT=""
     # This may fail while the machine is down so generate output and a
@@ -96,23 +82,12 @@ function check_if_rebooted() {
     if grep -q "0" "${output_file}"; then
       if grep -q "1" "${output_file}"; then
         info "Not yet rebooted"
-        sleep .5
       else
         info "Rebooted and responding"
         break
       fi
     fi
-  done
-}
-
-function remote_reboot() {
-  info "Rebooting."
-  remote_sh "touch /tmp/awaiting_reboot; reboot"
-  while true; do
-    check_if_rebooted &
-    local pid=$!
-    wait_with_timeout ${pid} 30 && break
-    ! kill -9 ${pid} 2> /dev/null
+    sleep .5
   done
 }