laterite_core/
config.rs

1//! Layered configuration loading.
2
3use std::path::Path;
4
5use config::{Config, Environment, File};
6use serde::de::DeserializeOwned;
7use serde::Deserialize;
8
9use crate::error::{CoreError, CoreResult};
10
11/// Database connection settings.
12#[derive(Debug, Clone, Deserialize)]
13pub struct DatabaseConfig {
14    pub url: String,
15    #[serde(default = "default_max_connections")]
16    pub max_connections: u32,
17    #[serde(default = "default_acquire_timeout_secs")]
18    pub acquire_timeout_secs: u64,
19}
20
21/// HTTP listener settings.
22#[derive(Debug, Clone, Deserialize)]
23pub struct ServerConfig {
24    #[serde(default = "default_listen")]
25    pub listen: String,
26}
27
28/// Deployment-level backend settings. Per-install brand and per-operator preferences
29/// live in the settings and preferences stores, not here.
30#[derive(Debug, Clone, Deserialize)]
31#[serde(default)]
32pub struct BackendConfig {
33    /// Set the `Secure` attribute on the admin session cookie. Enable behind HTTPS
34    /// in production; leave off for plain-HTTP local development.
35    pub secure_cookie: bool,
36    /// The default display timezone for the admin (an IANA name like
37    /// `Asia/Kolkata`). Storage is always UTC; this only affects how dates render.
38    /// An operator's own preference overrides it (later); it falls back to UTC.
39    pub timezone: String,
40}
41
42impl Default for BackendConfig {
43    fn default() -> Self {
44        Self {
45            secure_cookie: false,
46            timezone: "UTC".to_string(),
47        }
48    }
49}
50
51fn default_max_connections() -> u32 {
52    10
53}
54
55fn default_acquire_timeout_secs() -> u64 {
56    5
57}
58
59fn default_listen() -> String {
60    "127.0.0.1:8080".to_string()
61}
62
63/// Loads a layered configuration into any deserializable type.
64///
65/// Layers, later overriding earlier:
66/// 1. `<dir>/default.toml` (required)
67/// 2. `<dir>/<APP_ENV>.toml` (optional; `APP_ENV` defaults to `development`)
68/// 3. `<dir>/local.toml` (optional, git-ignored developer overrides)
69/// 4. Environment variables `<PREFIX>__SECTION__KEY` (e.g. `APP__DATABASE__URL`)
70pub fn load<T: DeserializeOwned>(dir: &Path, env_prefix: &str) -> CoreResult<T> {
71    let app_env = std::env::var("APP_ENV").unwrap_or_else(|_| "development".into());
72    Config::builder()
73        .add_source(File::from(dir.join("default.toml")).required(true))
74        .add_source(File::from(dir.join(format!("{app_env}.toml"))).required(false))
75        .add_source(File::from(dir.join("local.toml")).required(false))
76        .add_source(
77            Environment::with_prefix(env_prefix)
78                .prefix_separator("__")
79                .separator("__"),
80        )
81        .build()
82        .and_then(Config::try_deserialize)
83        .map_err(|e| CoreError::Config(e.to_string()))
84}
85
86#[cfg(test)]
87mod tests {
88    use super::*;
89
90    #[derive(Deserialize)]
91    struct TestConfig {
92        server: ServerConfig,
93        database: DatabaseConfig,
94    }
95
96    #[test]
97    fn loads_defaults_env_overrides_and_serde_defaults() {
98        let dir = tempfile::tempdir().unwrap();
99        std::fs::write(
100            dir.path().join("default.toml"),
101            "[server]\nlisten = \"0.0.0.0:9999\"\n\n[database]\nurl = \"postgres://from-file\"\n",
102        )
103        .unwrap();
104        std::env::set_var("LATERITE_TEST__DATABASE__URL", "postgres://from-env");
105        let cfg: TestConfig = load(dir.path(), "LATERITE_TEST").unwrap();
106        std::env::remove_var("LATERITE_TEST__DATABASE__URL");
107        assert_eq!(cfg.server.listen, "0.0.0.0:9999");
108        assert_eq!(cfg.database.url, "postgres://from-env");
109        assert_eq!(cfg.database.max_connections, 10);
110        assert_eq!(cfg.database.acquire_timeout_secs, 5);
111    }
112
113    #[test]
114    fn backend_config_defaults_and_loads() {
115        #[derive(Deserialize)]
116        struct C {
117            #[serde(default)]
118            backend: BackendConfig,
119        }
120        let dir = tempfile::tempdir().unwrap();
121        std::fs::write(dir.path().join("default.toml"), "").unwrap();
122        let c: C = load(dir.path(), "LATERITE_BE_NONE").unwrap();
123        assert!(!c.backend.secure_cookie);
124        assert_eq!(c.backend.timezone, "UTC");
125
126        std::fs::write(
127            dir.path().join("default.toml"),
128            "[backend]\nsecure_cookie = true\ntimezone = \"Asia/Kolkata\"\n",
129        )
130        .unwrap();
131        let c: C = load(dir.path(), "LATERITE_BE_SET").unwrap();
132        assert!(c.backend.secure_cookie);
133        assert_eq!(c.backend.timezone, "Asia/Kolkata");
134    }
135
136    #[test]
137    fn missing_default_file_is_a_config_error() {
138        let dir = tempfile::tempdir().unwrap();
139        let result: CoreResult<TestConfig> = load(dir.path(), "LATERITE_TEST_MISSING");
140        assert!(matches!(result, Err(CoreError::Config(_))));
141    }
142}
laterite_core/config.rs

laterite_core/
config.rs
