Move JDBC / Migratus logic to database component (#50)

Author: bryanmikaelian

components/database/src/com/vennbilling/database/core.clj

@@ -1,9 +1,55 @@
 (ns com.vennbilling.database.core
   (:require
+   [honey.sql :as sql]
+   [migratus.core :as migratus]
    [next.jdbc :as jdbc]
-   [honey.sql :as sql])
+   [next.jdbc.connection :refer [jdbc-url]]
 
-  (:import (javax.sql DataSource)))
+   [com.vennbilling.logging.interface :as log])
+
+  (:import [javax.sql DataSource]
+           [java.sql SQLException]
+           [com.zaxxer.hikari HikariDataSource]))
+
+(defn- build-jdbc-url
+  [dbtype config]
+  (let [{:keys [database-name]} config
+        conn (dissoc config :database-name)
+        db (assoc conn :dbname database-name :dbtype dbtype)]
+    (jdbc-url db)))
+
+(defn establish-connection
+  [dbtype config]
+  (let [jdbc-url (build-jdbc-url dbtype config)
+        ds (HikariDataSource.)]
+
+    (try
+      ;; Configure the datastore
+      (-> ds
+          (.setJdbcUrl jdbc-url))
+
+      ;; Test DB Connection
+      (log/info (str "Testing database connection to " dbtype "..."))
+      (let [test-conn (.getConnection ds)]
+        (log/info (str "Database connection to " dbtype " is healthy"))
+        (.close test-conn)
+
+        ;; Return the datasource
+        ds)
+
+      (catch SQLException e
+        (let [ex (ex-info "Unable to connect to database" {:cause :sql-exception :exception e})]
+          (throw ex))))))
+
+(defn bootstrap
+  [migratus-config]
+  (if (seq (migratus/pending-list migratus-config))
+    (do
+      (log/info "Bootstrapping database. Running all migrations...")
+      (migratus/migrate migratus-config)
+      (log/info "Bootstrapping complete."))
+
+    (log/info "Skipped bootstrapping database. Schema is up to date.")))
 
 (defn exec!
   [conn q]

components/database/src/com/vennbilling/database/interface.clj

@@ -1,6 +1,16 @@
 (ns com.vennbilling.database.interface
   (:require [com.vennbilling.database.core :as db]))
 
+(defn establish-connection
+  "Establishes a connection database using the provided configuration and returns a javax.sql.Datasource."
+  [dbtype config]
+  (db/establish-connection dbtype config))
+
+(defn bootstrap
+  "Bootstraps a database, running all pending migrations with migratus"
+  [migratus-config]
+  (db/bootstrap migratus-config))
+
 (defn exec!
   "Executes a query designed to not return any rows"
   [conn q]

components/system/src/com/vennbilling/system/storage.clj

@@ -1,16 +1,11 @@
 (ns com.vennbilling.system.storage
   (:require [integrant.core :as ig]
             [malli.core :as m]
-            [next.jdbc.connection :refer [jdbc-url]]
 
             [com.vennbilling.logging.interface :as log]
-            [com.vennbilling.database.interface]
-            [migratus.core :as migratus])
+            [com.vennbilling.database.interface :as database])
 
-  (:import [com.zaxxer.hikari HikariDataSource]
-           [java.sql Connection SQLException]
-
-           [clojure.lang ExceptionInfo]))
+  (:import  [clojure.lang ExceptionInfo]))
 
 ;; Supported Storage Engines
 (derive :storage.type/postgresql :db/connection)
@@ -42,16 +37,9 @@
    [:password {:optional true} :string]
    [:migrations DBMigrationsConfig]])
 
-(defn- build-jdbc-url
-  [dbtype config]
-  (let [{:keys [database-name]} config
-        conn (dissoc config :database-name)
-        db (assoc conn :dbname database-name :dbtype dbtype)]
-    (jdbc-url db)))
-
 (defn- build-migrations-config
   "Returns a map that represents a configuration used by migratus.core"
-  [^HikariDataSource datasource {:keys [directory managed-connection]}]
+  [datasource {:keys [directory managed-connection]}]
   {:store :database
    :migration-dir directory
    :db {:datasource datasource
@@ -71,38 +59,19 @@
   (try
     (let [valid-db-config (m/coerce DBConfig db-config)
           dbtype (name storage-type)
-          db (dissoc valid-db-config :migrations)
-          jdbc-url (build-jdbc-url dbtype db)
-          ^HikariDataSource ds (new HikariDataSource)]
-
-      ;; Configure the datastore
-      (-> ds
-          (.setJdbcUrl jdbc-url))
-
-      ;; Test DB Connection
-      (log/info (str "Testing database connection to " dbtype "..."))
-      (let [^Connection test-conn (.getConnection ds)]
-        (log/info (str "Database connection to " dbtype " is healthy"))
-        (.close test-conn)
-
-        ;; Configure Migrations
-        (let [migratus-config (build-migrations-config ds migrations)]
-
-          (if (and (bootstrap? storage-type) (seq (migratus/pending-list migratus-config)))
-            (do
-              (log/info "Bootstrapping database. Running all migrations...")
-              (migratus/migrate migratus-config)
-              (log/info "Bootstrapping complete."))
-            (log/info "Skipped bootstrapping database. Schema is up to date."))
-
-          (log/info (str "Database " dbtype " is ready to accept connections."))
-          {:datasource ds :migrations-config migratus-config})))
+          db-connection-config (dissoc valid-db-config :migrations)
+          ds (database/establish-connection dbtype db-connection-config)
+          migratus-config (build-migrations-config ds migrations)]
+
+      (when (bootstrap? storage-type)
+        (database/bootstrap migratus-config))
+
+      (log/info (str "Database " dbtype " is configured and ready to accept connections."))
+
+      {:datasource ds :migrations-config migratus-config})
     (catch ExceptionInfo e
       (log/exception e)
-      (throw (IllegalArgumentException. (ex-message e))))
-    (catch SQLException e
-      (log/exception (ex-info "Unable to connect to database" {:cause :sql-exception :exception e}))
-      (throw e))))
+      (throw (IllegalArgumentException. (ex-message e))))))
 
 (defmethod ig/halt-key! :db/connection
   [storage-type db]