init

Author: zOxta

README.md

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+# prerequisites
+
+1. Create two DigitalOcean servers in the same data center.
+2. Create a floating IP @ DigitalOcean (you can find that in the 'Networking' tab).
+3. Point the floating IP to the primary server.
+
+# steps
+
+1. Make sure you python3 is installed, as well as python3-requests `apt-get install python3 python3-requests`
+
+2. Edit `floating-ip-droplet-id.py` and replace `YOU_DIGITAL_OCEAN_API_KEY` by your actual DigitalOcean API key.
+
+3. Move `floating-ip-droplet-id.py` to /usr/local/bin/floating-ip-droplet-id then make it executable `chmod +x /usr/local/bin/floating-ip-droplet-id`
+
+4. Edit `do-assign-floating-ip.py` and replace `YOU_DIGITAL_OCEAN_API_KEY` by your actual DigitalOcean API key.
+
+5. Move `do-assign-floating-ip.py` to /usr/local/bin/do-assign-floating-ip then make it executable `chmod +x /usr/local/bin/do-assign-floating-ip`
+
+# syncing both servers
+
+- You can either deploy your code via git to both servers (can be easily done using Laravel Forge).
+- You can setup file syncing between the two servers using rsync, both servers first need to be able to use a public/private key authentication to communicate with each other.

crontab-entry

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+# for the primary server, add the following cron command
+* * * * * sh /path/to/primary-server-failover.sh >> /path/to/primary-server-failover.log 2>&1
+
+# for the secondary server, add the following cron command
+* * * * * sh /path/to/secondary-server-failover.sh >> /path/to/secondary-server-failover.log 2>&1

do-assign-floating-ip.py

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+#!/usr/bin/python3
+
+import os
+import sys
+import requests
+import json
+
+api_base = 'https://api.digitalocean.com/v2'
+
+
+def usage():
+    print('{} [Floating IP] [Droplet ID]'.format(sys.argv[0]))
+
+
+def main(floating_ip, droplet_id):
+    payload = {'type': 'assign', 'droplet_id': droplet_id}
+    headers = {'Authorization': 'Bearer YOU_DIGITAL_OCEAN_API_KEY',
+               'Content-type': 'application/json'}
+    url = api_base + "/floating_ips/{}/actions".format(floating_ip)
+    r = requests.post(url, headers=headers,  data=json.dumps(payload))
+
+    resp = r.json()
+    if 'message' in resp:
+        print('{0}: {1}'.format(resp['id'], resp['message']))
+        sys.exit(1)
+    else:
+        print('Moving IP address: {}'.format(resp['action']['status']))
+
+if __name__ == "__main__":
+    if not len(sys.argv) > 2:
+        usage()
+        sys.exit()
+    main(sys.argv[1], sys.argv[2])

floating-ip-droplet-id.py

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+#!/usr/bin/python3
+
+import os
+import sys
+import requests
+import json
+
+api_base = 'https://api.digitalocean.com/v2'
+
+def main():
+    headers = {'Authorization': 'Bearer YOU_DIGITAL_OCEAN_API_KEY',
+               'Content-type': 'application/json'}
+    url = api_base + "/floating_ips"
+    r = requests.get(url, headers=headers)
+
+    resp = r.json()
+    if 'message' in resp:
+        print('{0}: {1}'.format(resp['id'], resp['message']))
+        sys.exit(1)
+    else:
+        print('{}'.format(resp['floating_ips'][0]['droplet']['id']))
+
+if __name__ == "__main__":
+    main()

primary-server-failover.sh

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+# digital ocean PRIMARY server failover script
+
+echo "\nchecking SECONDARY server status"
+
+# digital ocean floating ip
+IP='xx.xx.xx.xx'
+
+# digital ocean PRIMARY server droplet id
+ID='xxxxxx'
+
+# digital ocean SECONDARY server public ip
+SECONDARY_SERVER_PUBLIC_IP='xx.xx.xx.xx'
+
+# digital ocean SECONDARY server health check
+SECONDARY_SERVER_STATUS=$(curl -o /dev/null --silent --head --write-out '%{http_code}\n' http://$SECONDARY_SERVER_PUBLIC_IP)
+
+HAS_FLOATING_IP=$(python3 /usr/local/bin/floating-ip-droplet-id)
+
+# if i the floating ip is not pointing to me and the SECONDARY server is down then assign floating ip to me
+if [ $HAS_FLOATING_IP != $ID ] && [ $SECONDARY_SERVER_STATUS = 000 ]; then
+
+    echo "\nSECONDARY server is down and has the floating ip"
+
+    n=0
+    while [ $n -lt 10 ]
+    do
+        echo "\nswitching to PRIMARY server $ID"
+        python3 /usr/local/bin/assign-ip $IP $ID && break
+        n=$((n+1))
+        sleep 3
+    done
+else
+    echo "\nno switch necessary\n"
+    echo $HAS_FLOATING_IP $SECONDARY_SERVER_STATUS $ID
+fi

secondary-server-failover.sh

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+# digital ocean SECONDARY server failover script
+
+echo "\nchecking PRIMARY server status"
+
+# digital ocean floating ip
+IP='xx.xx.xx.xx'
+
+# digital ocean SECONDARY server droplet id
+ID='xxxxxx'
+
+# digital ocean PRIMARY server public ip
+PRIMARY_SERVER_PUBLIC_IP='xx.xx.xx.xx'
+
+# digital ocean PRIMARY server health check
+PRIMARY_SERVER_STATUS=$(curl -o /dev/null --silent --head --write-out '%{http_code}\n' http://$PRIMARY_SERVER_PUBLIC_IP)
+
+HAS_FLOATING_IP=$(python3 /usr/local/bin/floating-ip-droplet-id)
+
+# if i the floating ip is not pointing to me and the PRIMARY server is down then assign floating ip to me
+if [ $HAS_FLOATING_IP != $ID ] && [ $PRIMARY_SERVER_STATUS = 000 ]; then
+
+    echo "\nPRIMARY server is down and has the floating ip"
+
+    n=0
+    while [ $n -lt 10 ]
+    do
+        echo "\nswitching to SECONDARY server $ID"
+        python3 /usr/local/bin/assign-ip $IP $ID && break
+        n=$((n+1))
+        sleep 3
+    done
+else
+    echo "\nno switch necessary\n"
+    echo $HAS_FLOATING_IP $PRIMARY_SERVER_STATUS $ID
+fi