Merged latest version of ELB/ASG scripts from aws-samples/aws-codedeploy-samples#43

default50 · default50 · commit 0176a4509021 · 2016-05-30T16:52:04.000+01:00
diff --git a/scripts/common_functions.sh b/scripts/common_functions.sh
@@ -34,6 +34,9 @@ WAITER_INTERVAL=1
 # AutoScaling Standby features at minimum require this version to work.
 MIN_CLI_VERSION='1.3.25'
 
+# Create a flagfile for each deployment
+FLAGFILE="/tmp/asg_codedeploy_flags-$DEPLOYMENT_GROUP_ID-$DEPLOYMENT_ID"
+
 # Usage: get_instance_region
 #
 #   Writes to STDOUT the AWS region as known by the local instance.
@@ -49,6 +52,125 @@ get_instance_region() {
 
 AWS_CLI="aws --region $(get_instance_region)"
 
+# Usage: set_flag <flag>
+#
+#   Writes <flag> to FLAGFILE
+set_flag() {
+  if echo "$1=true" >> $FLAGFILE; then
+    #msg "$1 flag written to $FLAGFILE"
+    return 0
+  else
+    error_exit "$1 flag NOT written to $FLAGFILE"
+  fi
+}
+
+# Usage: get_flag <flag>
+#
+#   Checks if <flag> is true in FLAGFILE
+get_flag() {
+  if [ -e $FLAGFILE ]; then
+    if grep "$1=true" $FLAGFILE > /dev/null; then
+      #msg "$1 flag found in $FLAGFILE"
+      return 0
+    else
+      #msg "$1 flag NOT found in $FLAGFILE"
+      return 1
+    fi
+  else
+    # FLAGFILE doesn't exist
+    return 1
+  fi
+}
+
+# Usage: check_suspended_processes
+#
+#   Checks processes suspended on the ASG before beginning and store them in
+#   the FLAGFILE to avoid resuming afterwards. Also abort if Launch process
+#   is suspended.
+check_suspended_processes() {
+  # Get suspended processes in an array
+  local suspended=($($AWS_CLI autoscaling describe-auto-scaling-groups \
+      --auto-scaling-group-name "${asg_name}" \
+      --query 'AutoScalingGroups[].SuspendedProcesses' \
+      --output text | awk '{printf $1" "}'))
+
+  if [ ${#suspended[@]} -eq 0 ]; then
+    msg "No processes were suspended on the ASG before starting."
+  else
+    msg "This processes were suspended on the ASG before starting: ${suspended[*]}"
+  fi
+
+  # If "Launch" process is suspended abort because we will not be able to recover from StandBy
+  if [[ "${suspended[@]}" =~ "Launch" ]]; then
+    error_exit "'Launch' process of AutoScaling is suspended which will not allow us to recover the instance from StandBy. Aborting."
+  fi
+
+  for process in ${suspended[@]}; do
+    set_flag $process
+  done
+}
+
+# Usage: suspend_processes
+#
+#   Suspend processes known to cause problems during deployments.
+#   The API call is idempotent so it doesn't matter if any were previously suspended.
+suspend_processes() {
+  local -a processes=(AZRebalance AlarmNotification ScheduledActions ReplaceUnhealthy)
+
+  msg "Suspending ${processes[*]} processes"
+  $AWS_CLI autoscaling suspend-processes \
+    --auto-scaling-group-name "${asg_name}" \
+    --scaling-processes ${processes[@]}
+  if [ $? != 0 ]; then
+    error_exit "Failed to suspend ${processes[*]} processes for ASG ${asg_name}. Aborting as this may cause issues."
+  fi
+}
+
+# Usage: resume_processes
+#
+#   Resume processes suspended, except for the one suspended before deployment.
+resume_processes() {
+  local -a processes=(AZRebalance AlarmNotification ScheduledActions ReplaceUnhealthy)
+  local -a to_resume
+
+  for p in ${processes[@]}; do
+    if ! get_flag "$p"; then
+      to_resume=("${to_resume[@]}" "$p")
+    fi
+  done
+
+  msg "Resuming ${to_resume[*]} processes"
+  $AWS_CLI autoscaling resume-processes \
+    --auto-scaling-group-name "${asg_name}" \
+    --scaling-processes ${to_resume[@]}
+  if [ $? != 0 ]; then
+    error_exit "Failed to resume ${to_resume[*]} processes for ASG ${asg_name}. Aborting as this may cause issues."
+  fi
+}
+
+# Usage: remove_flagfile
+#
+#   Removes FLAGFILE
+remove_flagfile() {
+  if rm -f $FLAGFILE; then
+      msg "Successfully removed flagfile $FLAGFILE"
+  else
+      error_exit "Failed to remove flagfile $FLAGFILE."
+  fi
+}
+
+# Usage: finish_msg
+#
+#   Prints some finishing statistics
+finish_msg() {
+  msg "Finished $(basename $0) at $(/bin/date "+%F %T")"
+  
+  end_sec=$(/bin/date +%s.%N)
+  elapsed_seconds=$(echo "$end_sec - $start_sec" | /usr/bin/bc)
+  
+  msg "Elapsed time: $elapsed_seconds"
+}
+
 # Usage: autoscaling_group_name <EC2 instance ID>
 #
 #    Prints to STDOUT the name of the AutoScaling group this instance is a part of and returns 0. If
@@ -101,25 +223,11 @@ autoscaling_enter_standby() {
         return 0
     fi
 
-    msg "Checking to see if ASG ${asg_name} had AZRebalance process suspended previously"
-    local azrebalance_suspended=$($AWS_CLI autoscaling describe-auto-scaling-groups \
-        --auto-scaling-group-name "${asg_name}" \
-        --query 'AutoScalingGroups[].SuspendedProcesses' \
-        --output text | grep -c 'AZRebalance')
-    if [ $azrebalance_suspended -eq 1 ]; then
-        msg "ASG ${asg_name} had AZRebalance suspended, creating flag file /tmp/azrebalanced"
-        # Create a "flag" file to denote that the ASG had AZRebalance enabled
-        touch /tmp/azrebalanced
-    else
-        msg "ASG ${asg_name} didn't have AZRebalance suspended, suspending"
-        $AWS_CLI autoscaling suspend-processes \
-            --auto-scaling-group-name "${asg_name}" \
-            --scaling-processes AZRebalance
-        if [ $? != 0 ]; then
-            msg "Failed to suspend the AZRebalance process for ASG ${asg_name}. Aborting as this may cause issues."
-            return 1
-        fi
-    fi
+    msg "Checking ASG ${asg_name} suspended processes"
+    check_suspended_processes
+
+    # Suspend troublesome processes while deploying
+    suspend_processes
 
     msg "Checking to see if ASG ${asg_name} will let us decrease desired capacity"
     local min_desired=$($AWS_CLI autoscaling describe-auto-scaling-groups \
@@ -143,9 +251,9 @@ autoscaling_enter_standby() {
             msg "Failed to reduce ASG ${asg_name}'s minimum size to $new_min. Cannot put this instance into Standby."
             return 1
         else
-            msg "ASG ${asg_name}'s minimum size has been decremented, creating flag file /tmp/asgmindecremented"
-            # Create a "flag" file to denote that the ASG min has been decremented
-            touch /tmp/asgmindecremented
+            msg "ASG ${asg_name}'s minimum size has been decremented, creating flag in file $FLAGFILE"
+            # Create a "flag" denote that the ASG min has been decremented
+            set_flag asgmindecremented
         fi
     fi
 
@@ -212,7 +320,7 @@ autoscaling_exit_standby() {
         return 1
     fi
     
-    if [ -a /tmp/asgmindecremented ]; then
+    if get_flag asgmindecremented; then
         local min_desired=$($AWS_CLI autoscaling describe-auto-scaling-groups \
             --auto-scaling-group-name "${asg_name}" \
             --query 'AutoScalingGroups[0].[MinSize, DesiredCapacity]' \
@@ -227,31 +335,20 @@ autoscaling_exit_standby() {
             --min-size $new_min)
         if [ $? != 0 ]; then
             msg "Failed to increase ASG ${asg_name}'s minimum size to $new_min."
+            remove_flagfile
             return 1
         else
             msg "Successfully incremented ASG ${asg_name}'s minimum size"
-            msg "Removing /tmp/asgmindecremented flag file"
-            rm -f /tmp/asgmindecremented
         fi
     else
         msg "Auto scaling group was not decremented previously, not incrementing min value"
     fi
 
-    if [ -a /tmp/azrebalanced ]; then
-        msg "ASG ${asg_name} had AZRebalance suspended previously, leaving it suspended"
-        msg "Removing /tmp/azrebalanced flag file"
-        rm -f /tmp/azrebalanced
-    else
-        msg "Resuming AZRebalance process for ASG ${asg_name}"
-        $AWS_CLI autoscaling resume-processes \
-            --auto-scaling-group-name "${asg_name}" \
-            --scaling-processes AZRebalance
-        if [ $? != 0 ]; then
-            msg "Failed to resume the AZRebalance process for ASG ${asg_name}. This may cause issues!"
-            return 1
-        fi
-    fi
+    # Resume processes, except for the ones suspended before deployment
+    resume_processes
 
+    # Clean up the FLAGFILE
+    remove_flagfile
     return 0
 }
 
diff --git a/scripts/deregister_from_elb.sh b/scripts/deregister_from_elb.sh
@@ -44,6 +44,7 @@ if [ $? == 0 -a -n "${asg}" ]; then
         error_exit "Failed to move instance into standby"
     else
         msg "Instance is in standby"
+        finish_msg
         exit 0
     fi
 fi
@@ -81,9 +82,4 @@ for elb in $ELB_LIST; do
     fi
 done
 
-msg "Finished $(basename $0) at $(/bin/date "+%F %T")"
-
-end_sec=$(/bin/date +%s.%N)
-elapsed_seconds=$(echo "$end_sec - $start_sec" | /usr/bin/bc)
-
-msg "Elapsed time: $elapsed_seconds"
+finish_msg
diff --git a/scripts/register_with_elb.sh b/scripts/register_with_elb.sh
@@ -44,6 +44,7 @@ if [ $? == 0 -a -n "${asg}" ]; then
         error_exit "Failed to move instance out of standby"
     else
         msg "Instance is no longer in Standby"
+        finish_msg
         exit 0
     fi
 fi
@@ -81,9 +82,4 @@ for elb in $ELB_LIST; do
     fi
 done
 
-msg "Finished $(basename $0) at $(/bin/date "+%F %T")"
-
-end_sec=$(/bin/date +%s.%N)
-elapsed_seconds=$(echo "$end_sec - $start_sec" | /usr/bin/bc)
-
-msg "Elapsed time: $elapsed_seconds"
+finish_msg
