chore: bootstrap rust service

.github/workflows/rust.yml

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+name: Rust
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+  workflow_dispatch:
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+env:
+  CARGO_PROFILE_DEV_DEBUG: line-tables-only
+  CARGO_PROFILE_TEST_DEBUG: line-tables-only
+  CARGO_INCREMENTAL: 0
+
+jobs:
+  check:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6
+
+      - uses: dtolnay/rust-toolchain@29eef336d9b2848a0b548edc03f92a220660cdb8 # stable
+        with:
+          components: clippy, rustfmt
+
+      - uses: Swatinem/rust-cache@e18b497796c12c097a38f9edb9d0641fb99eee32 # v2
+
+      - name: cargo fmt
+        run: cargo fmt --all --check
+
+      - name: cargo clippy
+        run: cargo clippy --locked --all-targets -- -D warnings
+
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6
+
+      - uses: dtolnay/rust-toolchain@29eef336d9b2848a0b548edc03f92a220660cdb8 # stable
+
+      - uses: Swatinem/rust-cache@e18b497796c12c097a38f9edb9d0641fb99eee32 # v2
+
+      - name: cargo test
+        run: cargo test --locked

.gitignore

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+/target/
+.env
+.DS_Store
+.coding-challenge-plan.md

Cargo.toml

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+[package]
+name = "pokedex-api"
+version = "0.1.0"
+edition = "2024"
+license = "MIT"
+publish = false
+
+[dependencies]
+axum = { version = "0.8", features = ["json", "macros"] }
+opentelemetry = "0.31"
+opentelemetry-prometheus-text-exporter = "0.2"
+opentelemetry_sdk = { version = "0.31", features = ["metrics"] }
+reqwest = { version = "0.12", default-features = false, features = ["json", "rustls-tls"] }
+serde = { version = "1", features = ["derive"] }
+serde_json = "1"
+thiserror = "2"
+tokio = { version = "1", features = ["macros", "net", "rt-multi-thread", "signal"] }
+tower = { version = "0.5", features = ["util"] }
+tower-http = { version = "0.6", features = ["request-id", "trace"] }
+tracing = "0.1"
+tracing-subscriber = { version = "0.3", features = ["env-filter", "json"] }
+uuid = { version = "1", features = ["v4"] }
+
+[dev-dependencies]
+http-body-util = "0.1"
+wiremock = "0.6"
+
+[lints.rust]
+unsafe_code = "forbid"
+
+[lints.clippy]
+all = { level = "deny", priority = -1 }
+pedantic = { level = "deny", priority = -1 }
+nursery = { level = "deny", priority = -1 }
+cargo = { level = "deny", priority = -1 }
+multiple_crate_versions = { level = "allow", priority = 1 }

src/config.rs

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+use std::{env, net::SocketAddr, time::Duration};
+
+#[derive(Clone, Debug, PartialEq)]
+pub struct AppConfig {
+    pub bind_addr: SocketAddr,
+    pub pokeapi_base_url: String,
+    pub translations_base_url: String,
+    pub request_timeout: Duration,
+    pub rate_limit_per_second: f64,
+    pub rate_limit_burst: u32,
+    pub service_name: String,
+}
+
+impl AppConfig {
+    pub fn from_env() -> Result<Self, ConfigError> {
+        Ok(Self {
+            bind_addr: env_or_parse("BIND_ADDR", default_bind_addr())?,
+            pokeapi_base_url: env_or_string("POKEAPI_BASE_URL", "https://pokeapi.co/api/v2"),
+            translations_base_url: env_or_string(
+                "FUN_TRANSLATIONS_BASE_URL",
+                "https://funtranslations.mercxry.me",
+            ),
+            request_timeout: Duration::from_secs(env_or_parse("REQUEST_TIMEOUT_SECONDS", 5)?),
+            rate_limit_per_second: env_or_parse("RATE_LIMIT_PER_SECOND", 20.0)?,
+            rate_limit_burst: env_or_parse("RATE_LIMIT_BURST", 40)?,
+            service_name: env_or_string("OTEL_SERVICE_NAME", env!("CARGO_PKG_NAME")),
+        })
+    }
+}
+
+#[derive(Debug, thiserror::Error)]
+pub enum ConfigError {
+    #[error("invalid value for {name}: {source}")]
+    InvalidValue {
+        name: &'static str,
+        source: Box<dyn std::error::Error + Send + Sync>,
+    },
+}
+
+fn env_or_string(name: &'static str, default: &str) -> String {
+    env::var(name).unwrap_or_else(|_| default.to_owned())
+}
+
+fn default_bind_addr() -> SocketAddr {
+    SocketAddr::from(([0, 0, 0, 0], 5000))
+}
+
+fn env_or_parse<T>(name: &'static str, default: T) -> Result<T, ConfigError>
+where
+    T: std::str::FromStr,
+    T::Err: std::error::Error + Send + Sync + 'static,
+{
+    env::var(name).map_or_else(
+        |_| Ok(default),
+        |value| {
+            value.parse().map_err(|source| ConfigError::InvalidValue {
+                name,
+                source: Box::new(source),
+            })
+        },
+    )
+}
+
+#[cfg(test)]
+mod tests {
+    use super::AppConfig;
+
+    #[test]
+    fn default_config_is_valid_for_local_development() {
+        let config = AppConfig::from_env().expect("default env should parse");
+
+        assert_eq!(config.bind_addr.port(), 5000);
+        assert_eq!(config.pokeapi_base_url, "https://pokeapi.co/api/v2");
+        assert!((config.rate_limit_per_second - 20.0).abs() < f64::EPSILON);
+    }
+}

src/lib.rs

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+#![deny(warnings)]
+#![deny(clippy::all, clippy::pedantic, clippy::nursery, clippy::cargo)]
+#![allow(clippy::missing_errors_doc, clippy::multiple_crate_versions)]
+
+pub mod config;
+
+#[must_use]
+pub const fn crate_name() -> &'static str {
+    env!("CARGO_PKG_NAME")
+}

src/main.rs

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+#![deny(warnings)]
+#![deny(clippy::all, clippy::pedantic, clippy::nursery, clippy::cargo)]
+#![allow(clippy::missing_errors_doc, clippy::multiple_crate_versions)]
+
+use pokedex_api::{config::AppConfig, crate_name};
+
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let _config = AppConfig::from_env()?;
+    println!("{name} bootstrap complete", name = crate_name());
+    Ok(())
+}