> ## Documentation Index
> Fetch the complete documentation index at: https://docs.streamnative.io/llms.txt
> Use this file to discover all available pages before exploring further.
# Develop Pulsar Functions in NodeJs(Private Preview)
This section introduces how to develop and pacakge NodeJs Pulsar functions to use on StreamNative cloud.
The NodeJs runtime is still in private preview stage, If you want to try it out or have any questions, please [submit a ticket](https://support.streamnative.io/hc/en-us/requests/new) to the support team.
## Develop
The StreamNative cloud will find the `process` method from the NodeJs function file, below is an example:
```node theme={null}
async function process(message, context) {
// 1. Get the logger to send logs to a Pulsar topic(when log-topic is set)
const logger = context.getLogger()
for (let word of message.split(' ')) {
// 2. Incre and Get counter from state store
await context.incrementCounter(word, 1)
let count = await context.getCounter(word)
logger.info(`got word: ${word} for ${count['value']} times`)
}
// 3. Get user-defined configurations
let cfg = context.getUserConfigValue('configKey')
// 4. Get secret configurations
let sec = context.getSecret('secretKey')
let result = `config: ${cfg}, secret: ${sec}`
// 5. Publish messages to any Pulsar topic
await context.publish(
'persistent://public/default/test-node-package-serde-extra',
result
)
// 6. Return the processing result
return message.concat('!')
}
```
It can also handle `Avro` and `Json` schema record, for `Avro` scheme input and output:
```node theme={null}
function process(params) {
params['grade']['int'] = params['grade']['int'] + 1
return params
}
const definitions = {
name: 'Student',
type: 'record',
fields: [
{ name: 'name', type: ['null', 'string'] },
{ name: 'age', type: ['null', 'int'] },
{ name: 'grade', type: ['null', 'int'] },
],
}
module.exports.definitions = definitions
```
For `Json` input and output:
```node theme={null}
function process(params) {
params['grade'] = params['grade'] + 1
return params
}
```
To get more examples, please refer to [examples](https://github.com/streamnative/pulsar-function-examples/tree/main/generic-runtime/nodejs)
### Feature Matrix
The NodeJs runtime doesn't support full features comparing to Java runtime, and it's still in developing, below is the matrix:
#### Input Arguments
| Input | Java | Go(Pulsar) | Python | NodeJs |
| :-------------------------- | :--- | :--------- | :----- | :----- |
| Custom SerDe | ✅ | ❌ | ✅ | ✅ |
| Schema - Avro | ✅ | ❌ | ✅ | ✅ |
| Schema - JSON | ✅ | ❌ | ✅ | ✅ |
| Schema - Protobuf | ✅ | ❌ | ❌ | ❌ |
| Schema - KeyValue | ✅ | ❌ | ❌ | ❌ |
| Schema - AutoSchema | ✅ | ❌ | ❌ | ❌ |
| Scehma - Protobuf Native | ✅ | ❌ | ❌ | ❌ |
| e-2-e encryption | ✅ | ❌ | ✅ | ✅ |
| maxMessageRetries | ✅ | ❌ | ❌ | ✅ |
| dead-letter policy | ✅ | ❌ | ❌ | ✅ |
| SubscriptionName | ✅ | ✅ | ✅ | ✅ |
| SubscriptionType | ✅ | ✅ | ✅ | ✅ |
| SubscriptionInitialPosition | ✅ | ❌ | ✅ | ✅ |
| AutoAck | ✅ | ✅ | ✅ | ✅ |
#### Output Arguments
| Output | Java | Go(Pulsar) | Python | NodeJs |
| :----------------------- | :--- | :--------- | :----- | :----- |
| Custom SerDe | ✅ | ❌ | ✅ | ✅ |
| Schema - Avro | ✅ | ❌ | ✅ | ✅ |
| Schema - JSON | ✅ | ❌ | ✅ | ✅ |
| Schema - Protobuf | ✅ | ❌ | ❌ | ❌ |
| Schema - KeyValue | ✅ | ❌ | ❌ | ❌ |
| Schema - AutoSchema | ✅ | ❌ | ❌ | ❌ |
| Schema - Protobuf Native | ✅ | ❌ | ❌ | ❌ |
| useThreadLocalProducers | ✅ | ❌ | ❌ | ✅ |
| Key-based Batcher | ✅ | ✅ | ✅ | ✅ |
| e-2-e encryption | ✅ | ❌ | ✅ | ✅ |
| Compression | ✅ | ✅ | ✅ | ✅ |
#### Context
| Context | Java | Go(Pulsar) | Python | NodeJs |
| :-------------------- | :--- | :--------- | :----- | :----- |
| InputTopics | ✅ | ✅ | ✅ | ✅ |
| OutputTopic | ✅ | ✅ | ✅ | ✅ |
| CurrentRecord | ✅ | ✅ | ✅ | ✅ |
| OutputSchemaType | ✅ | ❌ | ✅ | ✅ |
| Tenant | ✅ | ✅ | ✅ | ✅ |
| Namespace | ✅ | ✅ | ✅ | ✅ |
| FunctionName | ✅ | ✅ | ✅ | ✅ |
| FunctionId | ✅ | ✅ | ✅ | ✅ |
| InstanceId | ✅ | ✅ | ✅ | ✅ |
| NumInstances | ✅ | ❌ | ✅ | ✅ |
| FunctionVersion | ✅ | ✅ | ✅ | ✅ |
| PulsarAdminClient | ✅ | ❌ | ❌ | ❌ |
| GetLogger | ✅ | ❌ | ✅ | ✅ |
| RecordMetrics | ✅ | ✅ | ✅ | ❌ |
| UserConfig | ✅ | ✅ | ✅ | ✅ |
| Secrets | ✅ | ❌ | ✅ | ✅ |
| State | ✅ | ❌ | ❌ | ✅ |
| Publish | ✅ | ✅ | ✅ | ✅ |
| ConsumerBuilder | ✅ | ❌ | ❌ | ❌ |
| Seek / Pause / Resume | ✅ | ❌ | ❌ | ❌ |
| PulsarClient | ✅ | ❌ | ❌ | ❌ |
#### Other
| Other | Java | Go(Pulsar) | Python | NodeJs |
| :--------------- | :--- | :--------- | :----- | :----- |
| Resources | ✅ | ✅ | ✅ | ✅ |
| At-most-once | ✅ | ✅ | ✅ | ✅ |
| At-least-once | ✅ | ✅ | ✅ | ✅ |
| Effectively-once | ✅ | ❌ | ✅ | ❌ |
## Package
You can either provide a single `.js` file or package your function into a `.zip` file when creating NodeJs functions.
A zip file should contain:
1. the `pacakge.json` file
2. other source code file
Like:
```
Archive: pad.zip
Length Method Size Cmpr Date Time CRC-32 Name
-------- ------ ------- ---- ---------- ----- -------- ----
107 Defl:N 89 17% 2024-03-01 01:07 918cdb62 index.js
94 Defl:N 78 17% 2024-03-01 01:07 2ed1db00 package.json
sidebarTitle: Develop NodeJs Functions
-------- ------- --- -------
201 167 17% 2 files
```
Below is an example of the `package.json`:
```json theme={null}
{
"name": "test",
"main": "index.js",
"dependencies": {
"left-pad": "1.3.0"
}
}
```
The "main" file is required for such `package.json`:
```node theme={null}
function process(message) {
const leftPad = require('left-pad')
return leftPad(message, 20, 'x')
}
```
The StreamNative Cloud will install dependencies specified in the `package.json` and handle your function.
## Deploy
After creating a cluster, set up your environment and develop\&package your function, you can use the `snctl`, `pulsarctl`, `pulsar-admin` command, the REST API, or `terraform` to deploy a Pulsar function to your cluster.
You can create a NodeJs Pulsar function by using a local `.js` or `.zip` file or an uploaded Pulsar functions package(recommend).
### (Optional) Upload your function file to Pulsar
It's recommended to upload your function file to Pulsar before you create a function. Since you can add a version suffix to the package.
Upload packages
```bash theme={null}
snctl pulsar admin packages upload function://${tenant}/${namespace}/${package_name} \
--path ${file_path} \
--description "${description}" \
--properties fileName=${file_name}
```
You should see the following output:
```bash theme={null}
The package 'function://${tenant}/${namespace}/${package_name}' uploaded from path '${file_path}' successfully
```
You need to set the context for Pulsarctl first:
```bash theme={null}
# create a context
pulsarctl context set ${context-name} \
--admin-service-url ${admin-service-url} \
--issuer-endpoint ${issuerUrl} \
--audience urn:sn:pulsar:${orgName}:${instanceName} \
--key-file ${privateKey}
# activate oauth2
pulsarctl oauth2 activate
```
Replace the placeholder variables with the actual values that you can get when [setting up client tools](/cloud/process/pulsar-functions/function-setup#set-up-client-tools).
* `context-name`: any name you want
* `admin-service-url`: the HTTP service URL of your Pulsar cluster.
* `privateKey`: the path to the downloaded OAuth2 key file.
* `issuerUrl`: the URL of the OAuth2 issuer.
* `audience`: the [Uniform Resource Name (URN)](/cloud/references/glossary#uniform-resource-name-urn), which is a combination of the `urn:sn:pulsar`, your organization name, and your Pulsar instance name.
* `${orgName}`: the name of your [organization](/cloud/references/glossary#organization).
* `${instanceName}`: the name of your [instance](/cloud/references/glossary#instance).
Upload packages
```bash theme={null}
pulsarctl packages upload function://${tenant}/${namespace}/${package_name} \
--path ${file_path} \
--description "${description}" \
--properties fileName=${file_name}
```
You should see the following output:
```bash theme={null}
The package 'function://${tenant}/${namespace}/${package_name}' uploaded from path '${file_path}' successfully
```
```bash theme={null}
./bin/pulsar-admin \
--admin-url "${WEB_SERVICE_URL}" \
--auth-plugin org.apache.pulsar.client.impl.auth.oauth2.AuthenticationOAuth2 \
--auth-params '{"privateKey":"file://${privateKey}","issuerUrl":"${issuerUrl}","audience":"urn:sn:pulsar:${orgName}:${instanceName}}' \
packages upload function://${tenant}/${namespace}/${package_name} \
--path ${file_path} \
--description "${description}" \
--properties fileName=${file_name}
```
Replace the placeholder variables with the actual values that you can get when [setting up client tools](/cloud/process/pulsar-functions/function-setup#set-up-client-tools).
* `admin-url`: the HTTP service URL of your Pulsar cluster.
* `privateKey`: the path to the downloaded OAuth2 key file.
* `issuerUrl`: the URL of the OAuth2 issuer.
* `audience`: the [Uniform Resource Name (URN)](/cloud/references/glossary#uniform-resource-name-urn), which is a combination of the `urn:sn:pulsar`, your organization name, and your Pulsar instance name.
* `${orgName}`: the name of your [organization](/cloud/references/glossary#organization).
* `${instanceName}`: the name of your [instance](/cloud/references/glossary#instance).
You should see the following output:
```bash theme={null}
The package 'function://${tenant}/${namespace}/${package_name}' uploaded from path '${file_path}' successfully
```
### Create
```bash theme={null}
snctl functions create \
--tenant public \
--namespace default \
--name function1 \
--inputs persistent://public/default/test-node-input \
--output persistent://public/default/test-node-output \
--classname exclamation \
--py function://public/default/node-exclamation@v0.1 \
--custom-runtime-options '{"genericKind": "nodejs"}'
--use-service-account
```
Since Pulsar doesn't support NodeJs runtime, we need to use `--py` to specify the function file and specify the `--custom-runtime-options '{"genericKind": "nodejs"}'` to make it work.
You should see something like this:
```bash theme={null}
Created function1 successfully
```
```bash theme={null}
pulsarctl functions create \
--tenant public \
--namespace default \
--name function1 \
--inputs persistent://public/default/test-node-input \
--output persistent://public/default/test-node-output \
--classname exclamation \
--py function://public/default/node-exclamation@v0.1 \
--custom-runtime-options '{"genericKind": "nodejs"}'
```
Since Pulsar doesn't support NodeJs runtime, we need to use `--py` to specify the function file and specify the `--custom-runtime-options '{"genericKind": "nodejs"}'` to make it work.
You should see something like this:
```bash theme={null}
Created function1 successfully
```
```bash theme={null}
./bin/pulsar-admin \
--admin-url "${WEB_SERVICE_URL}" \
--auth-plugin org.apache.pulsar.client.impl.auth.oauth2.AuthenticationOAuth2 \
--auth-params '{"privateKey":"file:///YOUR-KEY-FILE-PATH","issuerUrl":"https://auth.streamnative.cloud/","audience":"urn:sn:pulsar:${orgName}:${instanceName}}' \
functions create \
--tenant public \
--namespace default \
--name function1 \
--inputs persistent://public/default/test-node-input \
--output persistent://public/default/test-node-output \
--classname exclamation \
--py function://public/default/node-exclamation@v0.1 \
--custom-runtime-options '{"genericKind": "nodejs"}'
```
Since Pulsar doesn't support NodeJs runtime, we need to use `--py` to specify the function file and specify the `--custom-runtime-options '{"genericKind": "nodejs"}'` to make it work.
You should see something like this:
```bash theme={null}
Created successfully
```
Create your terraform yaml file:
```yaml theme={null}
terraform {
required_providers {
pulsar = {
version = "0.2.0"
source = "registry.terraform.io/streamnative/pulsar"
}
}
}
provider "pulsar" {
web_service_url = "{$admin-url}"
api_version = "3"
audience = "urn:sn:pulsar:${orgName}:${instanceName}}"
issuer_url = "${issuerUrl}"
key_file_path = "${privateKey}"
}
// Note: function resource requires v3 api.
resource "pulsar_function" "function-1" {
provider = pulsar
name = "function1"
tenant = "public"
namespace = "default"
parallelism = 1
processing_guarantees = "ATLEAST_ONCE"
py = "function://public/default/node-exclamation@v0.1"
classname = "exclamation.ExclamationFunction"
inputs = ["persistent://public/default/test-node-input"]
output = "persistent://public/default/test-node-output"
subscription_name = "test-sub"
subscription_position = "Latest"
cleanup_subscription = true
skip_to_latest = true
forward_source_message_property = true
retain_key_ordering = true
auto_ack = true
max_message_retries = 100
dead_letter_topic = "public/default/dlt"
log_topic = "public/default/lt"
timeout_ms = 6666
secrets = jsonencode(
{
"SECRET1": {
"path": "sectest",
"key": "hello"
}
})
custom_runtime_options = jsonencode(
{
"genericKind": "nodejs",
"env": {
"HELLO": "WORLD"
}
})
}
```
Since Pulsar doesn't support NodeJs runtime, we need to use `--py` to specify the function file and specify the `--custom-runtime-options '{"genericKind": "nodejs"}'` to make it work.
Init the terraform provider in the same dir of your `.tf` file if you haven't done it:
```bash theme={null}
terraform init
```
You should see something like this:
```bash theme={null}
Initializing the backend...
Initializing provider plugins...
- Finding streamnative/pulsar versions matching "0.2.0"...
- Installing streamnative/pulsar v0.2.0...
- Installed streamnative/pulsar v0.2.0 (self-signed, key ID 3105E1011F3C3671)
Partner and community providers are signed by their developers.
If you'd like to know more about provider signing, you can read about it here:
https://www.terraform.io/docs/cli/plugins/signing.html
Terraform has created a lock file .terraform.lock.hcl to record the provider
selections it made above. Include this file in your version control repository
so that Terraform can guarantee to make the same selections by default when
you run "terraform init" in the future.
Terraform has been successfully initialized!
You may now begin working with Terraform. Try running "terraform plan" to see
any changes that are required for your infrastructure. All Terraform commands
should now work.
If you ever set or change modules or backend configuration for Terraform,
rerun this command to reinitialize your working directory. If you forget, other
commands will detect it and remind you to do so if necessary.
```
Create the function:
```bash theme={null}
terraform apply
```
You should see something like:
```bash theme={null}
Terraform used the selected providers to generate the following execution plan. Resource actions are indicated with the following symbols:
+ create
Terraform will perform the following actions:
# pulsar_function.function-1 will be created
+ resource "pulsar_function" "function-1" {
+ auto_ack = true
+ classname = "exclamation.ExclamationFunction"
+ cleanup_subscription = true
+ cpu = 0.5
+ custom_runtime_options = jsonencode(
{
+ genericKind = "nodejs",
+ env = {
+ HELLO = "WORLD"
}
}
)
+ dead_letter_topic = "public/default/dlt"
+ disk_mb = 128
+ forward_source_message_property = true
+ id = (known after apply)
+ inputs = [
+ "persistent://public/default/test-node-input",
]
+ py = "function://public/default/node-exclamation@v0.1"
+ log_topic = "public/default/lt"
+ max_message_retries = 100
+ name = "function1"
+ namespace = "default"
+ output = "persistent://public/default/test-node-output"
+ parallelism = 1
+ processing_guarantees = "ATLEAST_ONCE"
+ ram_mb = 128
+ retain_key_ordering = true
+ secrets = jsonencode(
{
+ SECRET1 = {
+ key = "hello"
+ path = "sectest"
}
}
)
+ skip_to_latest = true
+ subscription_name = "test-sub"
+ subscription_position = "Latest"
+ tenant = "public"
+ timeout_ms = 6666
}
Plan: 1 to add, 0 to change, 0 to destroy.
Do you want to perform these actions?
Terraform will perform the actions described above.
Only 'yes' will be accepted to approve.
Enter a value:
```
After enter "yes", you should see the following:
```bash theme={null}
pulsar_function.function-1: Creating...
pulsar_function.function-1: Creation complete after 1s [id=public/default/function1]
Apply complete! Resources: 1 added, 0 changed, 0 destroyed.
```
Replace the placeholder variables with the actual values that you can get when [setting up client tools](/cloud/process/pulsar-functions/function-setup#set-up-client-tools).
* `admin-url`: the HTTP service URL of your Pulsar cluster.
* `privateKey`: the path to the downloaded OAuth2 key file.
* `issuerUrl`: the URL of the OAuth2 issuer.
* `audience`: the [Uniform Resource Name (URN)](/cloud/references/glossary#uniform-resource-name-urn), which is a combination of the `urn:sn:pulsar`, your organization name, and your Pulsar instance name.
* `${orgName}`: the name of your [organization](/cloud/references/glossary#organization).
* `${instanceName}`: the name of your [instance](/cloud/references/glossary#instance).
If you would like to create a function configuration using the REST API you can
do so using CURL.
```bash theme={null}
curl -X POST ${WEB_SERVICE_URL}/admin/v3/functions/public/default/${FUNCTION_NAME} \
-H 'Authorization: Bearer ${TOKEN}' \
-H "Content-Type: multipart/form-data" \
-F 'functionConfig={"name": "${FUNCTION_NAME}", "tenant": "public", "namespace": "default", "runtime": "PYTHON", "py": "function://public/default/${PACKAGE_NAME}@${PACKAGE_VERSION}", "output": "public/default/output-test", "inputs": ["public/default/input"], "className": "exclamation", "customRuntimeOptions": "{\"genericKind\": \"nodejs\"}"};type=application/json' \
-F 'url=function://public/default/${PACKAGE_NAME}@${PACKAGE_VERSION}'
```
Since Pulsar doesn't support NodeJs runtime, we need to use `--py` to specify the function file and specify the `--custom-runtime-options '{"genericKind": "nodejs"}'` to make it work.
The function is assumed to be already uploaded at this point. If you have not
uploaded the function, change the `url` parameter to be your local filepath.
This will look something like the following.
```bash theme={null}
-F 'url=file://$YOUR_LCOAL_FUNCTION_FILE'
```
You should see something like this:
```bash theme={null}
Created successfully
```
Replace the placeholder variables with the actual values that you can get when [setting up client tools](/cloud/process/pulsar-functions/function-setup#set-up-client-tools).
* `WEB_SERVICE_URL`: the HTTPS service URL of your Pulsar cluster.
* `TOKEN`: a valid token to interact with your Pulsar cluster.
* `FUNCTION_NAME`: the name of your function.
* `FUNCTION_VERSION`: the version of your function you want to deploy e.g. 1.12.
For details about Pulsar function configurations, see [Pulsar function configurations](/cloud/process/pulsar-functions/function-config).
## What’s next?
* Learn how to develop [WASM functions](/cloud/process/pulsar-functions/develop-functions/function-develop-wasm).
* Learn how to [manage functions](/cloud/process/pulsar-functions/function-manage).
* Learn how to [configure stateful functions](/cloud/process/pulsar-functions/function-state).
* Learn how to [monitor functions](/cloud/process/pulsar-functions/function-monitoring).
* Reference [common configurations](/cloud/process/pulsar-functions/function-config).