Diagram: Example of Client communicating via hybrid runner with automatic wasm retrieval
To configure `nodegen-server` for automatic Wasm module retrieval, you need to set the following environment variables.
| Environment variable | Description |
| ------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `USE_SAAS` |
false
This must always be set as false. The setting of true is for Coherent deployments on our SaaS environments. The default value is true.
|
| `SERVICE_ENDPOINTS__EXCELENGINE_SERVICEURL` | The base URL of your Spark SaaS account `https://excel.{environment}.coherent.global`. |
| `SAAS_SERVICE_AUTH_TYPE` | `syntheticKey` or `OAuth2` |
| `SAAS_SERVICE_SYNTHETIC_KEY` |
If SAAS\_SERVICE\_AUTH\_TYPE is syntheticKey then this value has to be configured.
If SAAS\_SERVICE\_AUTH\_TYPE is OAuth2 then this value has to be configured.
|
| `SAAS_SERVICE_OAUTH_CLIENT_ID` |
If SAAS\_SERVICE\_AUTH\_TYPE is OAuth2 then this value has to be configured. This can be setup with /pages/RP037PouT3w6NbkrkRtT.
|
| `SAAS_SERVICE_OAUTH_CLIENT_SECRET` |
If SAAS\_SERVICE\_AUTH\_TYPE is OAuth2 then this value has to be configured. This can be setup with /pages/RP037PouT3w6NbkrkRtT.
|
| `CLEANUP_INTERVAL` | The interval in milliseconds before cleaning up any downloaded Wasm modules. The default value is `43200000` milliseconds (`12` hours). |
1. Ensure that the Docker engine/daemon is up and running.
2. [`pull`](https://docs.docker.com/reference/cli/docker/image/pull/) the [`nodegen-server`](https://github.com/orgs/Coherent-Partners/packages/container/package/nodegen-server) Docker image using the following command:
```bash
docker pull ghcr.io/coherent-partners/nodegen-server
```
3. [`run`](https://docs.docker.com/engine/reference/commandline/run/) the service and create a container called `wasm-server.`
1. Define the parameters that will be used for authorization to the Spark servers. In this example we are using a `syntheticKey` for authorization.
```bash
docker run --name wasm-server -p 3000:3000 -d -it \
-e USE_SAAS=false \
-e SAAS_SERVICE_AUTH_TYPE=syntheticKey \
-e SERVICE_ENDPOINTS__EXCELENGINE_SERVICEURL=https://excel.myenvironment.coherent.global \
-e SAAS_SERVICE_SYNTHETIC_KEY=22f68e51-b04b-4a46-b0aa-a629a8a3fca8 \
-e CLEANUP_INTERVAL=43200000 \
ghcr.io/coherent-partners/nodegen-server
```
4. Test the service using the `healthcheck` endpoint. You should receive the message `{"msg":"ok"}`.
```sh
curl 'http://localhost:3000/healthcheck'
```
5. Execute a request similar to that in the [API Tester](/navigation/api-tester.md).
* Note the change in the URI to `localhost:3000` and make sure to update `mytenant` in the URI to your tenant name.
* See [Execute API (v3)](/spark-apis/execute-api/execute-api-v3.md) for more information on the [Execute API (v3)](/spark-apis/execute-api/execute-api-v3.md#request_data) and [Execute API (v3)](/spark-apis/execute-api/execute-api-v3.md#request_meta) structure and options.
* Also see the [Hybrid Runner API reference](/hybrid-runner/hybrid-runner-api-reference.md) for alternative endpoints available from the runner.
```sh
curl --location --request POST 'http://localhost:3000/mytenant/api/v3/execute' \
--header 'Content-Type: application/json' \
--data '{
"request_data": {
"inputs": { "A": 1 , "B": 2 }
},
"request_meta": {
"version_id": "c16d9b89-92c4-430f-a30e-9b04805fcb78",
"call_purpose": "Online",
"source_system": "Hybrid Runner"
}
}'
```
6. [`nodegen-server`](https://github.com/orgs/Coherent-Partners/packages/container/package/nodegen-server) will first perform a lookup and verify whether the Spark service was already downloaded and cached locally.
* If the service is not found locally, [`nodegen-server`](https://github.com/orgs/Coherent-Partners/packages/container/package/nodegen-server) will use the provided Spark credentials to download the Wasm module from the SaaS platform and cache it until the `CLEANUP_INTERVAL` is reached.
* If the service is found locally, [`nodegen-server`](https://github.com/orgs/Coherent-Partners/packages/container/package/nodegen-server) will execute the Wasm module by loading it into memory, running the encapsulated logic, and returning the results back to the end-user.
7. It is good practice to [`stop`](https://docs.docker.com/engine/reference/commandline/stop/) and [`remove`](https://docs.docker.com/engine/reference/commandline/rm/) containers when you are finished.
```bash
# stop the container
docker stop wasm-server
# remove the container
docker rm wasm-server
```
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