The starting state for our repo after the csv upload course is a Cargo Workspace, which means we can add a new package to the crates directory.

To add a new crate to the workspace we can use cargo new on the directory that we want the crate to live in. In our case we'll put that in crates/pokemon-api which results in a new crate called pokemon-api in our workspace members directory.

cargo new crates/pokemon-api

You should see a typical new Rust project in crates/pokemon-api, including a scaffolded Cargo.toml.

[package]
name = "pokemon-api"
version = "0.1.0"
edition = "2021"

# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

[dependencies]

Building crates

If we run cargo build now.

cargo build

cargo will try to build the whole workspace. We know this because we'll get a build error for the upload-pokemon-api saying it needs DATABASE_URL set to build properly.

error: `DATABASE_URL` must be set, or `cargo sqlx prepare` must have been run and .sqlx must exist, to use query macros

To build a specific package (pokemon-api) we can use the -p flag.

cargo build -p pokemon-api

Since we also know the binary name, we could use the --bin flag as well.

cargo build --bin pokemon-api

The difference between these two flags is that a package can contain multiple binaries, so -p would build all of the binaries in that package while --bin would only build one.

Cargo.lock

When we create the new crate, we also get a change to Cargo.lock reflecting that.

+[[package]]
+name = "pokemon-api"
+version = "0.1.0"