From 3be842c6536c7c7df54d93c4db0c9e5662a0001b Mon Sep 17 00:00:00 2001
From: KITAITI Makoto <KitaitiMakoto@gmail.com>
Date: Thu, 7 May 2020 02:27:59 +0900
Subject: [PATCH] Make database connections configurable by environment
 variables (#768)

* Make env DB_MAX_SIZE and DB_MIN_IDLE recognizable

* Make database max size and minimum idle configurable

* Restore file permission

* Fail fast
---
 plume-models/src/config.rs | 10 ++++++++++
 src/main.rs                |  9 ++++++---
 2 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/plume-models/src/config.rs b/plume-models/src/config.rs
index 40cece6d..03e08a1b 100644
--- a/plume-models/src/config.rs
+++ b/plume-models/src/config.rs
@@ -11,6 +11,8 @@ pub struct Config {
     pub base_url: String,
     pub database_url: String,
     pub db_name: &'static str,
+    pub db_max_size: Option<u32>,
+    pub db_min_idle: Option<u32>,
     pub search_index: String,
     pub rocket: Result<RocketConfig, RocketError>,
     pub logo: LogoConfig,
@@ -193,6 +195,14 @@ lazy_static! {
             var("ROCKET_PORT").unwrap_or_else(|_| "7878".to_owned())
         )),
         db_name: DB_NAME,
+        db_max_size: var("DB_MAX_SIZE").map_or(None, |s| Some(
+            s.parse::<u32>()
+                .expect("Couldn't parse DB_MAX_SIZE into u32")
+        )),
+        db_min_idle: var("DB_MIN_IDLE").map_or(None, |s| Some(
+            s.parse::<u32>()
+                .expect("Couldn't parse DB_MIN_IDLE into u32")
+        )),
         #[cfg(feature = "postgres")]
         database_url: var("DATABASE_URL")
             .unwrap_or_else(|_| format!("postgres://plume:plume@localhost/{}", DB_NAME)),
diff --git a/src/main.rs b/src/main.rs
index 5016e982..ed203049 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -55,10 +55,13 @@ fn init_pool() -> Option<DbPool> {
     }
 
     let manager = ConnectionManager::<Connection>::new(CONFIG.database_url.as_str());
-    let pool = DbPool::builder()
+    let mut builder = DbPool::builder()
         .connection_customizer(Box::new(PragmaForeignKey))
-        .build(manager)
-        .ok()?;
+        .min_idle(CONFIG.db_min_idle);
+    if let Some(max_size) = CONFIG.db_max_size {
+        builder = builder.max_size(max_size);
+    };
+    let pool = builder.build(manager).ok()?;
     Instance::cache_local(&pool.get().unwrap());
     Some(pool)
 }