Hello World Example using ArmoniK’s C ABI

This project demonstrates a “Hello World” example using ArmoniK’s low-level C ABI directly, without the C++ SDK worker wrapper. The worker plugin is written in pure C and implements the five armonik_* functions defined in ArmoniKSDKInterface.h. The client is written in C++ and uses the ArmoniK C++ SDK.

The example supports three behaviors selected via a command-line flag:

Flag	Worker behavior	Expected outcome
(none)	Appends `" World!"` to the input and returns it	Task succeeds with result `"Hello, World!"`
`--error`	Returns `ARMONIK_STATUS_ERROR`	Task fails permanently, no retry
`--retry`	Returns `ARMONIK_STATUS_RETRY`	Task is retried until `max_retries` is exhausted, then fails

Prerequisites

An ArmoniK cluster with a partition running the dynamic C++ worker provided by the SDK. If you already deployed ArmoniK and wish to add such a partition, follow these steps:

Add a cppdynamic partition to your infrastructure.

+cppdynamic = {
+  replicas = 0
+  polling_agent = { ... }
+  worker = [
+    {
+      image = "dockerhubaneo/armonik-sdk-cpp-dynamicworker"
+      tag   = "0.5.0"
+      limits   = { ... }
+      requests = { ... }
+    }
+  ]
+  hpa = { ... }
+}

Redeploy ArmoniK to include the new partition.

Building and running the example

Building in your system

Install the right packages for your distribution:
- ArmoniK.Api
- ArmoniK.Extensions.Cpp
Compile the worker shared library and copy it to ArmoniK’s shared data folder.

The worker only needs gcc — no C++ compiler is required.
```
cd worker && mkdir build
cmake -B build -S .
cmake --build ./build
```
This produces libArmoniK.Samples.C.Hello.Worker.so. Copy it to ArmoniK’s shared data folder — for a localhost deployment the default is infrastructure/quick-deploy/localhost/data/.
Compile the client.
```
cd client && mkdir build
cmake -B build -S .
cmake --build ./build
```
This produces ArmoniK.Samples.C.Hello.Client. It reads the following configuration, either from environment variables or from an appsettings.json file placed next to the executable:
```
{
  "GrpcClient": { "Endpoint": "http://xxx.xxx.xxx:5001" },
  "PartitionId": "cppdynamic"
}
```

Run the client.

# Normal hello task (succeeds)
./ArmoniK.Samples.C.Hello.Client

# Trigger a permanent task error
./ArmoniK.Samples.C.Hello.Client --error

# Trigger a transient error that exhausts retries
./ArmoniK.Samples.C.Hello.Client --retry

Using Docker containers

The provided Makefile builds both images:

make build_worker
make build_client
# or both at once
make all

Copy the worker library to ArmoniK’s shared data folder before starting the client:

docker run --rm \
  -v /path/to/armonik/data:/host \
  --entrypoint sh armonik-samples-c-hello-worker:0.0.0 \
  -c "cp /app/libArmoniK.Samples.C.Hello.Worker.so /host/"

Run the client:

# Normal hello task
docker run --rm \
  -e GrpcClient__Endpoint=http://xxx.xxx.xxx:5001 \
  -e PartitionId=cppdynamic \
  armonik-samples-c-hello-client:0.0.0

# Permanent error
docker run --rm \
  -e GrpcClient__Endpoint=http://xxx.xxx.xxx:5001 \
  -e PartitionId=cppdynamic \
  armonik-samples-c-hello-client:0.0.0 --error

# Transient error / retry
docker run --rm \
  -e GrpcClient__Endpoint=http://xxx.xxx.xxx:5001 \
  -e PartitionId=cppdynamic \
  armonik-samples-c-hello-client:0.0.0 --retry

Expected output for the normal case:

[Info]  Starting Hello World ArmoniK Client (pure C worker), mode: hello
[Info]  Session ID: 3fbeebca-083d-416a-b0db-f866d92d13f5
[Info]  Task Submitted: e4cdeead-5fb2-4892-a643-82cd17393e90
[Info]  HANDLE RESPONSE : Received result of size 13 for taskId e4cdeead-5fb2-4892-a643-82cd17393e90
        Content : Hello, World!
[Info]  Task Processing Complete.

Expected output for the error case:

2026-04-27T11:32:19.206365939z	[Info]	Starting Hello World ArmoniK Client (pure C worker), mode: error
Unable to load json file ./appsettings.json : IO_ERROR: Error reading the file.2026-04-27T11:32:19.218309917z	[Info]Session ID: 6159a9d8-2d15-4b97-8914-9740d7fb04d8
2026-04-27T11:32:19.253967120z	[Info]	Task Submitted: f7ca0cd4-1f98-43c6-a8c8-3b8f113cff4d
2026-04-27T11:32:19.775699094z	[Error]	Error while handling result 59a5e417-6bca-4b66-a49c-b4840872f7fe for task f7ca0cd4-1f98-43c6-a8c8-3b8f113cff4d : Result is aborted : TaskId : f7ca0cd4-1f98-43c6-a8c8-3b8f113cff4d Errors : 
TASK_STATUS_ERROR : Permanent error requested by client
2026-04-27T11:32:19.775725731z	[Error]	HANDLE ERROR : Error for task id f7ca0cd4-1f98-43c6-a8c8-3b8f113cff4d : Result is aborted : TaskId : f7ca0cd4-1f98-43c6-a8c8-3b8f113cff4d Errors : 
TASK_STATUS_ERROR : Permanent error requested by client

2026-04-27T11:32:20.276001425z	[Info]	Task Processing Complete.

Expected output for the retry case ( the client sets max_retries=3 in the corresponding session for this case):

2026-04-27T11:41:02.510129823z	[Info]	Starting Hello World ArmoniK Client (pure C worker), mode: retry
Unable to load json file ./appsettings.json : IO_ERROR: Error reading the file.2026-04-27T11:41:02.521919924z	[Info]Session ID: 5102c075-7e2d-48fc-b938-497293f96d4a
2026-04-27T11:41:02.555341296z	[Info]	Task Submitted: c844a085-8ba0-4b20-8767-5973e5d91620
2026-04-27T11:41:03.570548731z	[Error]	Error while handling result 8b2f1c81-e87b-4a57-8613-9e224c35eaea for task c844a085-8ba0-4b20-8767-5973e5d91620 : Result is aborted : TaskId : c844a085-8ba0-4b20-8767-5973e5d91620###3 Errors : 
TASK_STATUS_ERROR : Worker associated to scheduling agent compute-plane-default-85b8458cf7-ntc6c is down with error: 
Status(StatusCode="Unavailable", Detail="Error processing task : Transient error requested by client, will retry")
2026-04-27T11:41:03.570593440z	[Error]	HANDLE ERROR : Error for task id c844a085-8ba0-4b20-8767-5973e5d91620 : Result is aborted : TaskId : c844a085-8ba0-4b20-8767-5973e5d91620###3 Errors : 
TASK_STATUS_ERROR : Worker associated to scheduling agent compute-plane-default-85b8458cf7-ntc6c is down with error: 
Status(StatusCode="Unavailable", Detail="Error processing task : Transient error requested by client, will retry")

2026-04-27T11:41:04.070765530z	[Info]	Task Processing Complete.

Notes

The worker is a pure C shared library. It has no dependency on the C++ SDK runtime or the ArmoniK API library at runtime — only ArmoniKSDKInterface.h is needed at compile time.
Error vs. retry semantics map directly to armonik_status_t return values: ARMONIK_STATUS_ERROR marks the task as permanently failed; ARMONIK_STATUS_RETRY signals a transient failure and causes ArmoniK to reschedule the task according to its max_retries policy.
Replace http://xxx.xxx.xxx:5001 with the correct endpoint for your control plane.
The image tags and package versions used in the Makefile can be overridden with environment variables (CLIENT_IMAGE_TAG, WORKER_IMAGE_TAG, API_VERSION, SDK_VERSION).