Sanity testing on startup.

src/smeagol/sanity.clj

@@ -0,0 +1,108 @@
+(ns ^{:doc "Functions related to sanity checks and error reporting in conditions where the environment may not be sane."
+      :author "Simon Brooke"}
+  smeagol.sanity
+  (:require [clojure.java.io :as cjio]
+            [clojure.string :as s]
+            [compojure.response :refer [Renderable]]
+            [environ.core :refer [env]]
+            [hiccup.core :refer [html]]
+            [ring.util.anti-forgery :refer [anti-forgery-field]]
+            [ring.util.response :refer [content-type response]]
+            [selmer.parser :as parser]
+            [smeagol.configuration :refer [config]]
+            [smeagol.util :as util]
+            [taoensso.timbre :as timbre]))
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;;;;
+;;;; Smeagol: a very simple Wiki engine.
+;;;;
+;;;; This program is free software; you can redistribute it and/or
+;;;; modify it under the terms of the GNU General Public License
+;;;; as published by the Free Software Foundation; either version 2
+;;;; of the License, or (at your option) any later version.
+;;;;
+;;;; This program is distributed in the hope that it will be useful,
+;;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;;;; GNU General Public License for more details.
+;;;;
+;;;; You should have received a copy of the GNU General Public License
+;;;; along with this program; if not, write to the Free Software
+;;;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
+;;;; USA.
+;;;;
+;;;; Copyright (C) 2014 Simon Brooke
+;;;;
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+(defn check-content-dir []
+  (try
+    (let [directory (cjio/as-file (cjio/resource util/content-dir))]
+      (if
+        (.isDirectory directory)
+        true
+        (throw (Exception. (str "Content directory '" util/content-dir "' is not a directory"))))
+      (if
+        (.canWrite directory)
+        true
+        (throw (Exception. (str "Content directory '" util/content-dir "' is not writable")))))
+    (catch Exception any
+      (throw (Exception. (str "Content directory '" util/content-dir "' does not exist") any))))
+  (try
+    (slurp (cjio/resource (str util/content-dir java.io.File/separator "_side-bar.md")))
+    (timbre/info "Content directory '" util/content-dir "' check completed.")
+    (catch Exception any
+      (throw (Exception. (str "Content directory '" util/content-dir "' is not initialised") any)))))
+
+
+(defn- raw-sanity-check-installation []
+  (check-content-dir)
+  (config :test))
+
+
+(defn sanity-check-installation []
+  (timbre/info "Running sanity check")
+  (check-content-dir)
+  (config :test)
+  (timbre/info "Sanity check completed"))
+
+
+;;(def sanity-check-installation (memoize raw-sanity-check-installation))
+
+
+(defn- get-causes [any]
+  (if
+    (instance? Exception any)
+    (cons any (get-causes (.getCause any)))
+    '()))
+
+
+(defn show-sanity-check-error
+  "Generate an error page in a way which should work even when everything else is broken.
+  If no argument is passed, run the sanity check and if it fails return page contents;
+  if `error` is passed, just return page content describing the error."
+  ([error]
+   (html
+     [:html
+      [:head
+       [:title "Smeagol is not initialised correctly"]
+       [:link {:href "/content/stylesheet.css" :rel "stylesheet"}]]
+      [:body
+       [:header
+        [:h1 "Smeagol is not initialised correctly"]]
+       [:div {:id "error"}
+        [:p {:class "error"} (.getMessage error)]]
+       [:p "There was a problem launching Smeagol probably because of misconfiguration:"]
+       (apply
+         vector
+         (cons :ol
+               (map #(vector :li (.getMessage %))
+                    (get-causes error))))
+       [:p "For more information please see documentation "
+        [:a {:href "https://github.com/journeyman-cc/smeagol/blob/develop/resources/public/content/Deploying%20Smeagol.md"} "here"]]]]))
+  ([]
+   (try
+     (sanity-check-installation)
+     nil
+     (catch Exception any (show-sanity-check-error any)))))