Make Uppercase (map)

Create a SmartModule that converts records to uppercase.

Prerequisites

• SDMK CLI is part of the Fluvio installation. Install Fluvio and start a local a cluster to build and test the SmartModule.

Generate a Smartmodule Project

Use SMDK generator to create a new SmartModule project of type map.

$ smdk generate uppercase
🤷   Please set a group name: acme
✔ 🤷   Which type of SmartModule would you like? · map
✔ 🤷   Will your SmartModule use init parameters? · false
✔ 🤷   Will your SmartModule be public? · false
[1/7]   Done: .gitignore
[2/7]   Done: Cargo.toml
[3/7]   Done: README.md
[4/7]   Done: SmartModule.toml
[5/7]   Done: rust-toolchain.toml
[6/7]   Done: src/lib.rss
[7/7]   Done: src    

Add Custom logic

Let's checkout the project tree:

$ cd uppercase; tree
.
├── Cargo.toml
├── README.md
├── SmartModule.toml
├── rust-toolchain.toml
└── src
    └── lib.rs

Replace the existing code in src/lib.rs with the following:

use fluvio_smartmodule::{smartmodule, Result, SmartModuleRecord, RecordData};

#[smartmodule(map)]
pub fn map(record: &SmartModuleRecord) -> Result<(Option<RecordData>, RecordData)> {
    let key = record.key.clone();

    let string = std::str::from_utf8(record.value.as_ref())?;
    let upper = string.to_string().to_uppercase();

    Ok((key, upper.into()))
}

Build and Test

It's time to build the SmartModule:

$ smdk build

Test the SmartModule:

$ smdk test --text "Hello in uppercase"
HELLO IN UPPERCASE

Load Smartmodule to your Cluster

You must upload the SmartModule to your cluster to use it.

$ smdk load
Creating SmartModule: uppercase

Ensure it has been uploaded by running the following command:

$ fluvio sm list
  SMARTMODULE                         SIZE     
  acme/uppercase@0.1.0                40.9 KB 

🎉 Congratulations! Your smartmodule is ready to use.