The poster watermark example

In this example, we demonstrate how to create and run a Rust function in the Second State Rust Functions.

Prerequisites

If you have not done so already, follow these simple instructions to install Rust and rustwasmc.

Build the WASM bytecode

rustwasmc build

FaaS

Upload the wasm file in the pkg folder to the FaaS. Double check the .wasm file name before you upload.

curl --location --request POST 'https://rpc.ssvm.secondstate.io:8081/api/executables' \
--header 'Content-Type: application/octet-stream' \
--header 'SSVM-Description: watermark' \
--data-binary '@pkg/watermark_lib_bg.wasm'

Returns

{"wasm_id":349,"wasm_sha256":"0x778fae35baf1d461b1e931d3c41964908947a2b3fbde02166b50d573f1e15959","SSVM_Usage_Key":"00000000-0000-0000-0000-000000000000","SSVM_Admin_Key":"50378009-bbbe-4043-8d7e-af80d0af531a"}

Note: You can update this binary with the SSVM_Admin_Key.

$ curl --location --request PUT 'https://rpc.ssvm.secondstate.io:8081/api/update_wasm_binary/349' \
--header 'Content-Type: application/octet-stream' \
--header 'SSVM_Admin_Key: 7dxxxxxx-xxxx-xxxx-xxxx-xxxxxxxx0c41' \
--data-binary '@pkg/watermark_lib_bg.wasm'

Insert your name

Add watermark to a local PNG image.

$ curl --location --request POST 'https://rpc.ssvm.secondstate.io:8081/api/multipart/run/148/watermark/bytes' \
--header 'Content-Type: multipart/form-data' \
--form 'input_1=Second State Functions' \
--output tmp.png

Serverless web app

Open web page html/index.html in any browser. See a static demo.

Local Test

When you changed the parameters in lib.rs, you may need to test your poster. For better local tests, we added main.rs.

If you want to change the input text, you need to open the main.rs.

vi src/main.rs

Run the following commland to see the tested result.

cargo run

If everything goes well, follow the aboving instructions to publish your web application.