SIAPP SDK README

The SIAPP SDK provides tools to build and emulate application containers, called SIAPPs. SIAPPs can run on hardware platforms like the SICAM A8000 series.

Table of Contents

• System Requirements
• Basics
• Quickstart
  • SIAPP Build
  • SIAPP Device Upload
  • SIAPP Docker Emulation
• Constraints
• Terms and Abbreviations
• Licensing
• Reporting Bugs and Security Issues

System Requirements

The SIAPP SDK is a platform software independent develoment kit and can be used on Windows and Linux.

• Windows Professional 10 (version 1803 or later) or Linux
• An up-to-date version of Docker Desktop (Windows) or Docker (Linux)
• For Linux with edgedata simulation you need QEMU
  e.g. for Debian 12.2:
  'sudo apt-get install qemu binfmt-support qemu-user-static' (Call once)
  'docker run --rm --privileged multiarch/qemu-user-static --reset -p yes' (Call after each restart)
• Python3

Basics

• Configure a SIAR on the platform you are working with. For further information, please refer to the device manual.
• Demo SIAPPs are provided within this repository, please take a look at chapter SIAPP Build.
• Upload the SIAPP into the device. For further information on how to upload, please refer to the device manual.
  Alternatively, an SIAPP Docker Emulation is provided where the SIAPP can be executed on your local machine using Docker.
  

Quickstart

This quick guideline goes into the build process of a SIAPP and its simulation. For limitations and constraints have a look at chapter Constraints.

Building a SIAPP

A SIAPP can be created by using the python3 script build.py. The PROJECT_PATH must contain the container project and a Dockerfile named Dockerfile.arm32v7.

python build.py PROJECT_PATH [--name NAME] [--version VERSION]

Example

Three demo projects: DemoProject, DemoSshd and CodeSnippets have been provided within this repository to demonstrate the usage of the SIAPP SDK and the EdgeData API. To get started, follow this step-by-step tutorial:

Open a terminal window within your desired working directory and use git clone to download this repository. To generate the DemoProject run build.py.

cd <YOUR_WORKING_DIRECTORY>
git clone https://github.com/siemens/siapp-sdk.git
python siapp-sdk/build.py DemoProject

The DemoProject SIAPP will now be generated. This may take a few minutes. It contains a basic web server to provide access to a set of configured example signals to the SIAPP.

The other examples DemoSshd and *CodeSnippets include an SSH daemon. No password or key is required. This SIAPP is for testing purposes only and should not be used in a production manner. The CodeSnippets SIAPP additionally contains examples on how to use the Edgedata API. The DemoSshd SIAPP can be generated by executing:

python siapp-sdk/build.py DemoSshd

After the build was successful, the SIAPP can be found in the ./siapp-sdk/build directory. To start the SIAPP, you have two options:

• Upload the SIAPP into a target (CP-8031 or CP-8050)
• Emulate the SIAPP on your local machine using Docker.

Device Upload

CP-8031/CP-8050

The minimum recommended SIAPP slot size, which can be found in the output of the build, should be considered in the SICAM Device Manager configuration. You can upload the SIAPP either by using the SICAM Device Manager or the SICAM Web. For a more detailed description, please refer to the SICAM Device Manager manual.

• The DemoProject starts a websever which is accessible on the containers port 8080. It provides access to all configured signals to the SIAPP.
• The DemoSshd Project includes a SSH daemon without password or key and is for testing purposes only and should not be used for production.
• The CodeSnippets Project includes a SSH daemon without password or key and is for testing purposes only and should not be used for production. It additionally contains small examples on how to use the Edgedata API.

Docker Emulation

Once a SIAPP has been created, it's possible to emulate the SIAPP's behaviour on your local machine using Docker and furthermore it's interaction with a Edgedata API simulation container.

To start the emulation you have to provide a discover.csv and a events.csv in your project directory. If no csv files are provided, default files will be used. The discover.csv contains all topics the API should provide and defines whether it is a read or write topic. The events.csv specifies the values and quality bits. The wait_ms column defines the delta time between the occurrences of topics. You can create recurring topics by setting GOTO x at the end of the CSV, where x stands for the line number the simulation should continue with.

discover.csv example:

topic;type;source
read01;UINT32;READ
read02;UINT32;READ
read03;UINT32;READ
read04;UINT32;READ
write01;UINT32;WRITE

events.csv example:

topic;quality;value;wait_ms
read01;NT|T|SB;10;2000
write01;NT|T|SB;10;100
read01;NT|T|SB;10;2000
write01;NT|T|SB;10;100
read01;IV|NT|T;11;2000
write01;IV|NT|T;11;100
read01;T|SB;10;2000
write01;T|SB;10;100
read01;;10;2000
write01;;10;100
GOTO 2;;;

A simulation can be started with the following command:

python run.py PROJECT_PATH [--name NAME] [--version VERSION]

Example

The emulation of the DemoProject web server can be reached via http://127.0.0.1:MAPPED_PORT. The MAPPED_PORT is printed out after the start of the emulation. If you use Docker Desktop click on the button OPEN IN BROWSER next to the docker sim container.

python siapp-sdk/run.py DemoProject

Constraints

Structure of a SIAPP Project

A project consists of a Dockerfile.arm32v7 which defines the SIAPP image and optionally a config.json which defines the container settings and limits. If no config.json is provided, a default config.json will be used. Note that the build.py script overwrites certain settings in the config.json if Docker is used:

• ENTRYPOINT or CMD in the Dockerfile will overwrite args in the config.json.
• WORKDIR will overwrite cwd.

Dockerfile constraints

The SICAM CP-8031/CP-8050 runs an armhf (ARM hard float) architecture. Therefore the dockerfile must be based on the same architecture.
If you want to use a pre-existing image from Docker hub, make sure it is compiled against armhf architecture. For example: FROM arm32v7/alpine can be used to build your SIAPP.
Also remove unnecessary and unused tools, packages or data from your container image during build process to reduce installation time and to keep the image lean. You may also consider using multi-stage builds.

Terms and Abbreviations

SIAPP

SIAPPs (SICAM Applications) can be used to run your own programs or pre-existing images from the Docker Hub on supported hardware. It is possible to access I/O signals, Ethernet interfaces and tested communication protocols in addition to the existing system features.

Some possible use cases:

• Web-based HMI APP - Run your own web server on CP-8050 fed with RTU data
• Analytics APP - Run your own data analytics algorithm and provide data via existing IEC or cloud protocols
• Controller APP - Port and run your existing C-code on performant CP-8050 hardware
• Server APP - Run your server beside existing RTU functionality within a secure environment – LDAP, Radius, SYSLOG, FTP, ...
• Customer specific APP - Create and run user-defined communication protocols or data point conversions

The SICAM A8000 platform currently supports multiple SIAPPs. Those SIAPPs are deployed into SIAPP Slots which are assigned to one of the SIARs (SICAM Application Runtimes). All that can be configured with the SICAM Device Manager, the engineering software for the SICAM A8000 series.

SIAPP SDK

The SIAPP SDK (SICAM Application Software Development Kit) is the toolchain to build and emulate SIAPPs.

SIAR

The SIAR (SICAM Application Runtime) defines the available Ethernet interfaces as well as it limits RAM or CPU usage and other runtime settings of the assigned SIAPPs. It is also possible to create virtual Ethernet interfaces to enable communication between SIARs or between SIARs and platform specific Web services (e.g. SICAM Web).

SIAPP slot

A SIAPP slot defines, amongst other things, the maximum Flash memory that is available for the SIAPP and provides the Edgedata API. A SIAPP can be uploaded into the SIAPP slot.
For further information and SIAPP deployment on the SICAM A8000 platform, please refer to the SICAM Device Manager manual.

Edgedata API

Via the Edgedata API you can access the topics which are assigned to the SIAPP slot in the SICAM Device Manager. Just add the EdgeDataApi folder to your project and access the API as described in the EdgeDataApi usage information.

Persistence

There is a persistent directory /persist_data that will not be erased during a SIAPP update.
Note that on the SICAM A8000 platform the persistent directory will be erased, if you change the SIAPP slot's size or if you delete the SIAPP slot and recreate it in the SICAM Device Manager.

Licensing

SIAPP SDK is primarily licensed under the terms of the MIT license.

Each of its source code files contains a license declaration in its header. Whenever a file is provided under an additional or different license than MIT, this is stated in the file header.

Reporting Bugs and Security Issues

Before opening an issue, check if the following conditions are met:

• The issue is related to siapp-sdk.
• There is no similar issue.

To make the investigation as simple as possible, please include the siapp-sdk version in your ticket.
If possible, add debug information and callstacks.