How to automatically restore Portainer on Kubernetes using the Portainer API

This guide shows how to automatically restore a Portainer instance on a Kubernetes cluster using:

• A monitoring script (portainer_hb.sh)
• The Portainer API
• An S3-compatible backup (for example, MinIO)

The script:

1. Monitors the primary Portainer instance
2. Deploys a new instance if the primary becomes unavailable
3. Restores from an S3 backup
4. Allows you to remap DNS to maintain continuity

Prerequisites

Before starting, ensure the following:

• Portainer is running on Kubernetes
• Portainer backups are configured to an S3-compatible bucket
• The Portainer instance is accessible via a FQDN
• kubectl is installed and configured for your cluster
• jq is installed (used to parse API responses)

After the restore process completes, update your DNS record to point your original FQDN to the new Portainer instance IP address. This is critical if you are using Edge Agents.

Step 1: Monitor the primary portainer instance

The script continuously checks whether the primary Portainer instance is reachable. It sends an unauthenticated API request. If the response contains "Unauthorized", the server is up. If not, failover begins.

while true
do
  portainer_up=$(curl --silent --insecure -X GET https://your-portainer-fqdn/api/status | jq -r '.details')

if [ "$portainer_up" = "Unauthorized" ]; then
      echo -ne 'Portainer is up\r'
  else
      break
  fi

sleep 5
done

Step 2: Deploy Portainer on the secondary kubernetes cluster

When the primary instance is unreachable, deploy Portainer on the secondary cluster.

kubectl apply -n portainer -f portainer.yaml
echo "Deploying Portainer server"

This assumes:

• A namespace named portainer exists
• You have a valid Portainer deployment manifest

Refer to our documentation on installing Portainer on your Kubernetes environment for more details.

Step 3: Wait until the new Portainer pod is running

Before restoring the backup, confirm that the new instance is fully operational.

while true
do
  portainer_running=$(kubectl get po -n portainer | tail -1 | awk '{print $3}')

if [ "$portainer_running" != "Running" ]; then
      echo -ne 'Portainer is not running yet\r'
  else
      break
  fi

sleep 1
done

This loop ensures:

• The pod status is Running
• The restore only begins once the server is ready

Step 4: Restore Portainer from an S3 backup

Once the new instance is running, use the Portainer API to restore from your S3 backup.

Set the following variables in your script:

• ACCESSKEYID: S3 access key
• SECRETKEY: S3 secret key
• BUCKETNAME: Bucket storing the backup
• FILENAME: Backup file name
• FILEPASSWORD: Backup password (if configured)
• REGIONS3: region
• SERVERS3: hostname or IP
• PORT: S3 service port

For example:

ACCESSKEYID="portainer"
BUCKETNAME="portainerbkp"
FILENAME="portainer-backup_2024-02-27_00-55-00.tar.gz"
FILEPASSWORD="restore1234"
REGION="us-east-1"
SERVER="s3server.example.com"
PORT="9001"
SECRETKEY="changeme"

Restore Call

curl -X POST \
  --insecure \
  --header "Content-Type: application/json" \
  --url https://new-portainer-instance/api/restore \
  --data "{
    \"accessKeyID\": \"$ACCESSKEYID\",
    \"bucketName\": \"$BUCKETNAME\",
    \"filename\": \"$FILENAME\",
    \"password\": \"$FILEPASSWORD\",
    \"region\": \"$REGION\",
    \"s3CompatibleHost\": \"$SERVER:$PORT\",
    \"secretAccessKey\": \"$SECRETKEY\"
  }"

After the restore completes:

• Update your DNS record to point the original FQDN to the new IP address
• Verify endpoints reconnect
• Confirm registries and authentication settings are intact

Check out our documentation for details on backing up to S3.

Complete script example

#!/bin/bash

# 1. Monitor primary instance
while true
do
  portainer_up=$(curl --silent --insecure -X GET https://your-portainer-fqdn/api/status | jq -r '.details')

if [ "$portainer_up" = "Unauthorized" ]; then
      echo -ne 'Portainer is up\r'
  else
      break
  fi

sleep 5
done

# 2. Deploy secondary instance
kubectl apply -n portainer -f portainer.yaml
echo "Deploying Portainer server"

# 3. Wait for pod to be running
while true
do
  portainer_running=$(kubectl get po -n portainer | tail -1 | awk '{print $3}')

if [ "$portainer_running" != "Running" ]; then
      echo -ne 'Portainer is not running yet\r'
  else
      break
  fi

sleep 1
done

sleep 5

# 4. Restore from S3
ACCESSKEYID="portainer"
BUCKETNAME="portainerbkp"
FILENAME="portainer-backup_2024-02-27_00-55-00.tar.gz"
FILEPASSWORD="restore1234"
REGION="us-east-1"
SERVER="s3server.example.com"
PORT="9001"
SECRETKEY="changeme"

curl -X POST \
  --insecure \
  --header "Content-Type: application/json" \
  --url https://new-portainer-instance/api/restore \
  --data "{
    \"accessKeyID\": \"$ACCESSKEYID\",
    \"bucketName\": \"$BUCKETNAME\",
    \"filename\": \"$FILENAME\",
    \"password\": \"$FILEPASSWORD\",
    \"region\": \"$REGION\",
    \"s3CompatibleHost\": \"$SERVER:$PORT\",
    \"secretAccessKey\": \"$SECRETKEY\"
  }"

echo "Portainer restored"

This approach provides:

• Automated failover detection
• Automated deployment
• Automated restore
• Minimal operational disruption

All existing configuration is preserved, including:

• Endpoints
• Registries
• Authentication
• Edge Agents

The result is continuity of service across Kubernetes clusters using the Portainer API and S3 backups.

Follow along with a video

The video below demonstrates the full automated restore workflow using the script.

In this example environment:

• The primary Portainer server runs on 192.168.10.171
• The secondary (failover) Portainer server runs on 192.168.10.176
• The S3-compatible backup server (MinIO) runs on 192.168.10.1

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