webui may be modified with custom style.css

README.md

@@ -66,7 +66,7 @@ For Apache, see [Apache Reverse Proxy](https://httpd.apache.org/docs/2.4/howto/r
 
 #### Set the page title
 
-Change `LAMINAR_TITLE` in `/etc/laminar.conf` to your preferred page title.
+Change `LAMINAR_TITLE` in `/etc/laminar.conf` to your preferred page title. For further WebUI customization, consider using a [custom style sheet](#customizing-the-webui).
 
 #### More configuration options
 
@@ -483,6 +483,11 @@ cmake src
 make
 ```
 
+### Customizing the WebUI
+
+If it exists, the file `/var/lib/laminar/custom/style.css` will be served by laminar and may be used to change the appearance of Laminar's WebUI.
+
+This directory is also a good place to add any extra assets needed for this customization, but note that in this case you will need to serve this directory directly from your [HTTP reverse proxy](#service-configuration) (highly recommended).
 
 ## Reference
 

src/interface.h

@@ -120,6 +120,11 @@ struct LaminarInterface {
     // $LAMINAR_HOME/archive. This shouldn't be used, because the sysadmin
     // should have configured a real webserver to serve these things.
     virtual bool getArtefact(std::string path, std::string& result) = 0;
+
+    // Fetches the content of $LAMINAR_HOME/custom/style.css or an empty
+    // string. This shouldn't be used, because the sysadmin should have
+    // configured a real webserver to serve these things.
+    virtual std::string getCustomCss() = 0;
 };
 
 #endif // LAMINAR_INTERFACE_H_

src/laminar.cpp

@@ -795,25 +795,38 @@ void Laminar::runFinished(Run * r) {
     }
 }
 
-bool Laminar::getArtefact(std::string path, std::string& result) {
-    if(archiveUrl != ARCHIVE_URL_DEFAULT) {
-        // we shouldn't have got here. Probably an invalid link.
-        return false;
-    }
-    // Reads in the whole file into the given string reference.
-    // This is a terrible way to serve files (especially large ones).
-    fs::path file(fs::path(homeDir)/"archive"/path);
-    // no support for browsing archived directories
-    if(fs::is_directory(file))
+// Small helper function to return the full contents of a file given its path.
+// It reads in the whole file into the given string reference.
+// This is a terrible way to serve files (especially large ones). Hopefully
+// no-one uses this function and configures their webservers appropriately.
+static bool slurp(fs::path path, std::string& output) {
+    if(!fs::is_regular_file(path))
         return false;
-    std::ifstream fstr(file.string());
+    std::ifstream fstr(path.string());
     fstr.seekg(0, std::ios::end);
     ssize_t sz = fstr.tellg();
     if(fstr.good()) {
-        result.resize(static_cast<size_t>(sz));
+        output.resize(static_cast<size_t>(sz));
         fstr.seekg(0);
-        fstr.read(&result[0], sz);
+        fstr.read(&output[0], sz);
         return true;
     }
     return false;
 }
+
+bool Laminar::getArtefact(std::string path, std::string& result) {
+    if(archiveUrl != ARCHIVE_URL_DEFAULT) {
+        // we shouldn't have got here. Probably an invalid link.
+        return false;
+    }
+    fs::path file(fs::path(homeDir)/"archive"/path);
+    return slurp(file, result);
+}
+
+std::string Laminar::getCustomCss()
+{
+    fs::path file(fs::path(homeDir)/"custom"/"style.css");
+    std::string result;
+    slurp(file, result);
+    return result;
+}

src/laminar.h

@@ -56,6 +56,7 @@ public:
     void sendStatus(LaminarClient* client) override;
     bool setParam(std::string job, uint buildNum, std::string param, std::string value) override;
     bool getArtefact(std::string path, std::string& result) override;
+    std::string getCustomCss() override;
 
 private:
     bool loadConfiguration();

src/resources/index.html

@@ -14,6 +14,7 @@
  <script src="/js/Chart.min.js"></script>
  <script src="/js/Chart.HorizontalBar.js"></script>
  <link href="/css/bootstrap.min.css" rel="stylesheet">
+ <link href="/custom/style.css" rel="stylesheet">
  <script src="/js/app.js" defer></script>
  <style>
   body, html { height: 100%; }

src/server.cpp

@@ -210,6 +210,10 @@ public:
                 } else {
                     c->set_status(websocketpp::http::status_code::not_found);
                 }
+            } else if(resource.compare("/custom/style.css") == 0) {
+                c->set_status(websocketpp::http::status_code::ok);
+                c->append_header("Content-Transfer-Encoding", "binary");
+                c->set_body(laminar.getCustomCss());
             } else if(resources.handleRequest(resource, &start, &end, &content_type)) {
                 c->set_status(websocketpp::http::status_code::ok);
                 c->append_header("Content-Type", content_type);