Making Legacy Machines Cloud-Ready: Retrofitting with Container Gateways
Making Legacy Machines Cloud-Ready: Retrofitting with Container Gateways

In many German factories, the backbone of our industry stands strong: reliable machines that have been operating efficiently for 10, 15, or even 20 years. Mechanically, these systems are often in top shape, but technically isolated. They don’t speak Cloud-Native, don’t understand JSON, and are invisible to modern data analysis. However, replacing a million-dollar investment is often uneconomical. The solution is Industrial Retrofitting using Container Gateways. Learn how to integrate your PLCs (Programmable Logic Controllers) into a modern Kubernetes infrastructure without touching the hardware. The problem: When the PLC doesn’t speak to the cloud.
Old controllers use protocols like Profibus, Modbus, or older S7 variants. These are optimized for local real-time control but not for transmission over Internet protocols (TCP/IP) or processing in Big Data clusters. The challenges in the IIoT upgrade:
- Proprietary protocols: Machines don’t “understand” the IT world.
- Security: Old controllers lack integrated security mechanisms for modern networks.
- Data volume: Unfiltered transmission of every signal would overwhelm bandwidth. The solution: The Container Gateway as a translator
Instead of replacing the PLC, we place an edge node (e.g., an industrial PC or a dedicated IoT gateway) in front of the machine. This node runs a lightweight container system (like K3s or Docker) that acts as an intelligent translator. Step 1: Protocol Abstraction (Southbound) In the first step, a container (e.g., based on open-source tools like Node-RED or Apache Hop) captures the data via the physical interface of the PLC. The old protocols are terminated locally. Step 2: Normalization and Filtering
Not every millimeter of a cylinder movement needs to go to the cloud. The container processes the data on-site:
- Aggregation: Average values instead of raw data.
- Anomaly detection: Only deviations trigger an alarm.
- Standardization: Conversion of signals into modern formats like MQTT or OPC UA. Step 3: Cloud Connectivity (Northbound) The edge node sends the processed data encrypted to a central managed Kubernetes cluster. From there, they can be used for predictive maintenance, dashboards, or ERP systems. Why Kubernetes is the best choice for retrofitting
One might think a simple industrial PC would suffice. But when retrofitting 50 or 100 machines, orchestration is needed.
- Central management: An update of the translator software is rolled out to all machines simultaneously via Kubernetes (e.g., via GitOps).
- Scalability: New analysis logic can be easily added as an additional container “next to” the translator.
- High availability: If a gateway node fails, the system reports it immediately, and replacement images can be quickly restarted on standardized hardware. The advantages of the ayedo approach
At ayedo, we know that “cloud” must function differently in the factory. We focus on:
- Vendor agnosticism: We don’t tie you to a specific hardware manufacturer.
- Security by design: The edge nodes act as a firewall between the insecure PLC world and the internet.
- Full managed service: We take care of the lifecycle of the containers so that your maintenance staff can focus on the machines. Conclusion: The machine stays, the data flows
Retrofitting with Container Gateways is the fastest and most cost-effective way to Industry 4.0. You maintain the longevity of your systems while benefiting from the agility of modern cloud technologies.
Want to digitize your existing systems? Let’s explore together how we can make your legacy machines “cloud-ready” safely and scalably.
FAQ – Briefly Explained:
What is IIoT retrofitting?
IIoT retrofitting is the technical modernization of existing industrial systems to make them networkable and internet-capable through additional sensors or communication gateways.
How do you connect old PLCs to Kubernetes?
By using edge gateways running container applications. These translate proprietary protocols (like Profibus) into modern standards (like MQTT) and forward them to the Kubernetes cluster.
What are the advantages of edge computing in retrofitting?
Edge computing reduces latency, saves bandwidth through local data preprocessing, and increases security by filtering and encrypting machine data before transmission.