Build from Dockerfile to improve caching

This should improve build times with changes that don't change the
dependencies in Cargo.toml.

Dockerfile.ci

@@ -0,0 +1,4 @@
+FROM rust:1.55
+COPY Cargo.toml .
+RUN cargo fetch
+COPY src/ ./src/

Jenkinsfile

@@ -1,8 +1,8 @@
 pipeline {
   agent {
-    docker {
-      image 'rust:1.55'
-      args '-v "$PWD":/usr/src/image-api'
+    dockerfile {
+      filename 'Dockerfile.ci'
+      args '-v "$PWD:/usr/src/image-api'
     }
   }
 

src/auth.rs

@@ -36,7 +36,7 @@ pub async fn login(
     if let Some(user) = user_dao.get_user(&creds.username, &creds.password) {
         let claims = Claims {
             sub: user.id.to_string(),
-            exp: (Utc::now() + Duration::days(5)).timestamp(),
+            exp: (Utc::now() + Duration::minutes(1)).timestamp(),
         };
         let token = encode(
             &Header::default(),