Rust on Kenno's Open Note

Axum custom request extractor and validator using FromRequest

Fri, 12 Jul 2024 16:41:07 +1000

This post documents what I learned about creating custom Axum extractor which can be used with the validator for validation.

Create a new test project:

➜ cargo new request-validator
cd request-validator

The first crate to be added is axum for Axum framework.

request-validator on  main [?] via 🦀 v1.79.0
➜ cargo add axum
    Updating crates.io index
      Adding axum v0.7.5 to dependencies
             Features:
             + form
             + http1
             + json
             + matched-path
             + original-uri
             + query
             + tokio
             + tower-log
             + tracing
             - __private_docs
             - http2
             - macros
             - multipart
             - ws
    Updating crates.io index
     Locking 82 packages to latest compatible versions
...

We also need tokio crate that works together with axum.

Rust cannot find derive macro `Serialize` in this scope

Wed, 22 May 2024 22:46:23 +1000

While trying out some Rust exercises, I came across the following error:

$ cargo run --bin iter2
   Compiling tutor-web-app-ssr v0.1.0 (/home/kenno/dev/rust/chapter7/ezytutors/tutor-web-app-ssr)
error: cannot find derive macro `Serialize` in this scope
  --> tutor-web-app-ssr/src/bin/iter2.rs:17:10
   |
17 | #[derive(Serialize, Deserialize)]
   |          ^^^^^^^^^
   |
note: `Serialize` is imported here, but it is only a trait, without a derive macro
  --> tutor-web-app-ssr/src/bin/iter2.rs:5:26
   |
5  | use serde::{Deserialize, Serialize};
   |                          ^^^^^^^^^

error: cannot find derive macro `Deserialize` in this scope
  --> tutor-web-app-ssr/src/bin/iter2.rs:17:21
   |
17 | #[derive(Serialize, Deserialize)]

<SNIP>

This happened because I didn’t specify the required dependency feature for serde crate. Here is what I had in Cargo.toml when the above error occurred:

Rustup - update and remove Rust toolchain

Thu, 19 Oct 2023 21:13:20 +1100

rustup is a utility used to install and remove rust toolchain.

To list the current installed toolchain run:

kenno@c2:~$ rustup show
Default host: aarch64-unknown-linux-gnu
rustup home:  /home/kenno/.rustup

installed toolchains
--------------------

stable-aarch64-unknown-linux-gnu (default)
1.70.0-aarch64-unknown-linux-gnu
1.71.1-aarch64-unknown-linux-gnu
1.72.0-aarch64-unknown-linux-gnu

active toolchain
----------------

stable-aarch64-unknown-linux-gnu (default)
rustc 1.72.0 (5680fa18f 2023-08-23)

To remove a specific version of the toolchain, e.g. 1.70.0-aarch64-unknown-linux-gnu run:

kenno@c2:~$ rustup toolchain remove 1.70.0-aarch64-unknown-linux-gnu
info: uninstalling toolchain '1.70.0-aarch64-unknown-linux-gnu'
info: toolchain '1.70.0-aarch64-unknown-linux-gnu' uninstalled

Let’s verify:

kenno@c2:~$ rustup show
Default host: aarch64-unknown-linux-gnu
rustup home:  /home/kenno/.rustup

installed toolchains
--------------------

stable-aarch64-unknown-linux-gnu (default)
1.71.1-aarch64-unknown-linux-gnu
1.72.0-aarch64-unknown-linux-gnu

active toolchain
----------------

stable-aarch64-unknown-linux-gnu (default)
rustc 1.72.0 (5680fa18f 2023-08-23)

To install udpate the new toolchain, run: