Adjusted frontpage_scale for personal use

configuration/manager/frontpage_scale.sh

+#!/bin/bash
+source /home/ubuntu/DCSG2003_V23_group45-openrc.sh
+source /home/ubuntu/dcsg2003/configuration/base.sh
+
+# Name of company
+COMPANY_NAME="AETA"
+
+# IP address of server 1 or whoever is the docker swarm leader
+SERVER_IP="192.168.134.127"
+
+# What is the lowest desired number of frontpage users?
+FRONTPAGE_COUNT_LIMIT=500
+
+# What increments do we increase in?
+SCALE_UP_INCREMENT=25
+
+# What increments do we decrease in?
+SCALE_DOWN_INCREMENT=50
+
+# What is the lower download time limit we would like to stay above?
+DOWNLOAD_TIME_LOWER_THRESHOLD=4.5
+
+# What is the upper download time limit we would like to stay below?
+DOWNLOAD_TIME_UPPER_THRESHOLD=5.5
+
+# SAFETY VALVE: Set this to "0" if you want the scaling to actually take place
+SAFETY_VALVE=1
+
+########################
+# SAFETY CHECK: Is bc installed?
+
+if ! which bc > /dev/null; then
+echo "You need to install the package 'bc' first"
+exit 1
+fi
+
+########################
+# Define function for scaling
+
+function scale {
+    # This script is assumed to run on the manager and SSH to a server
+    # in order to run the docker service upgrade command.
+    # we also assume that we need to use sudo.
+
+    COMMAND="sudo docker service update --env-add BF_FRONTPAGE_LIMIT=$1 bf_web"
+
+    # This could be improved, because what happens when server 1 is unavailable?
+
+    SSH_COMMAND="ssh -t ubuntu@$SERVER_IP "
+
+    if [ "$SAFETY_VALVE" -eq "0" ]; then
+        # Safety valve is off, we're running the command
+        $SSH_COMMAND $COMMAND
+
+    else
+        # Saftey valve is on, we only print what we would do
+        discord_log "Safety valve is on, this is what would be executed: "
+        echo $SSH_COMMAND $COMMAND
+
+    fi
+
+}
+
+################################
+# Check if the site is up. Exit if it's down.
+
+STATUS=$( curl -s -g 'http://admin:admin@192.168.132.61:9090/api/v1/query?query=last_status{name="'$COMPANY_NAME'"}' | jq -r '.data.result[].value[1] ')
+
+if [ "$STATUS" -gt "0" ]; then
+    discord_log "Site is considered up"
+else
+    discord_log "Site is considered down, we should stop here"
+    exit 1
+fi
+
+################################
+# The site is up, so we can proceed with checking its performance
+# Get current download times:
+DOWNLOAD_TIME=$( curl -s -g 'http://admin:admin@192.168.132.61:9090/api/v1/query?query=last_download_time{name="'$COMPANY_NAME'"}' | jq -r '.data.result[].value[1] ')
+    NUMBER_OF_FRONTPAGE_USERS=$( curl -s -g 'http://admin:admin@192.168.132.61:9090/api/v1/query?query=frontpage_count{name="'$COMPANY_NAME'"}' | jq -r '.data.result[].value[1] ')
+    discord_log "Observed download time: $DOWNLOAD_TIME"
+
+# check if we are below the lower threshold. If we are, we scale up
+if (( $(echo "$DOWNLOAD_TIME < $DOWNLOAD_TIME_LOWER_THRESHOLD" | bc -l) )); then
+    NEW_FRONTPAGE_COUNT=$( echo "$NUMBER_OF_FRONTPAGE_USERS + $SCALE_UP_INCREMENT" | bc )
+    discord_log "Download time was lower, we have some capacity to spare. Scaling up to $NEW_FRONTPAGE_COUNT"
+    scale $NEW_FRONTPAGE_COUNT
+
+# check if we are above the higher threshold. If we are, scale down, but not lower than the limit
+elif (( $(echo "$DOWNLOAD_TIME > $DOWNLOAD_TIME_UPPER_THRESHOLD" | bc -l) )); then
+
+    # We can't go lower than the bottom
+    if [ "$NUMBER_OF_FRONTPAGE_USERS" -eq "$FRONTPAGE_COUNT_LIMIT" ]; then
+        discord_log "We should go lower, but we are already at the limit"
+        exit 0
+    fi
+
+    # Lowering the number of frontpage users
+    NEW_FRONTPAGE_COUNT=$( echo "$NUMBER_OF_FRONTPAGE_USERS - $SCALE_DOWN_INCREMENT" | bc )
+
+    if [ "$NEW_FRONTPAGE_COUNT" -lt "$FRONTPAGE_COUNT_LIMIT" ]; then
+        discord_log "We should scale down, but can't go lower then the limit, so we end up at $FRONTPAGE_COUNT_LIMIT"
+        NEW_FRONTPAGE_COUNT=$FRONTPAGE_COUNT_LIMIT
+    else
+        discord_log "Scaling down to $NEW_FRONTPAGE_COUNT as new frontpage_limit"
+        scale $NEW_FRONTPAGE_COUNT
+    fi
+
+fi
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