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94 lines
2.1 KiB
Markdown
94 lines
2.1 KiB
Markdown
# Tutorial 1: Rust Function w/ Input (3 minutes)
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This example will show you how to test and deploy Rust code to Oracle Functions. It will also demonstrate passing data in through stdin.
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The easiest way to create a function in rust is via ***cargo*** and ***fn***.
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### Prerequisites
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Create an empty rust project as follows:
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```bash
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cargo init --name func --bin
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```
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Make sure the project name is ***func*** and is of type ***bin***.
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Now put the following code in ```main.rs``` (can also copy directly from the file in this repo):
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```rust
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use std::io;
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use std::io::Read;
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fn main() {
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let mut buffer = String::new();
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let stdin = io::stdin();
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if stdin.lock().read_to_string(&mut buffer).is_ok() {
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println!("Hello {}", buffer.trim());
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}
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}
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```
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### Now run the following commands:
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```sh
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# Initialize your function creating a func.yaml file
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fn init --name hello-rust
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# Test your function. This will run inside a container exactly how it will on the server
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fn run
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# Now try with an input (copy sample.payload.json from this repo)
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cat sample.payload.json | fn run
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# Deploy your functions to the Oracle Functions server (default localhost:8080)
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# This will create a route to your function as well
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fn deploy --app myapp
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```
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### Now call your function:
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```sh
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curl http://localhost:8080/r/myapp/hello-rust
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```
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Or call from a browser: [http://localhost:8080/r/myapp/hello-rust](http://localhost:8080/r/myapp/hello-rust)
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And now with the JSON input:
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```sh
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curl -H "Content-Type: application/json" -X POST -d @sample.payload.json http://localhost:8080/r/myapp/hello-rust
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```
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That's it!
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### Note on Dependencies
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# In Review
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1. We piped JSON data into the function at the command line
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```sh
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cat sample.payload.json | fn run
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```
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2. We received our function input through **stdin**
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```rust
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read_to_string(&mut buffer)
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```
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3. We wrote our output to **stdout**
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```rust
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println!("Hello {}", buffer.trim());
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```
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4. We sent **stderr** to the server logs
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```rust
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TODO
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```
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# Next Up
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## [Tutorial 2: Input Parameters](../../params)
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