Community login page [Visualforce]

MyLoginPage.apexp

apex:page controller="SiteLoginController" id="loginComponent" showheader="false" standardStylesheets="false">
  
  <h1 style="color: gray"> Community Login </h1>

  <apex:form id="loginForm" forceSSL="true">
    <apex:outputPanel layout="block">
      <apex:pageMessages id="error"/>

        <apex:outputLabel value="{!$Label.site.username}" for="username"/>
        <apex:inputText id="username" value="{!username}"/>
        <apex:outputLabel value="{!$Label.site.password}" for="password"/>
        <apex:inputSecret id="password" value="{!password}"/>
        <apex:outputText value=""/>
        <apex:commandButton action="{!login}" value="{!$Label.site.login_button}" id="loginButton"/>


    </apex:outputPanel>
  </apex:form>
  
  If you're an employee, you can go here:

<!-- NOTE: You will need to change this based on your community (currently hardcoded) -->
  <a href="https://login.salesforce.com//servlet/networks/session/create?portal=060D00000000XYT&amp;site=0DMD0000000054I&amp;inst=D">Log in here</a>
</apex:page>

SiteLoginController.apex

/**
 * An apex page controller that exposes the site login functionality
 */
global with sharing class SiteLoginController {
    global String username {get; set;}
    global String password {get; set;}

    global PageReference login() {
        String startUrl = System.currentPageReference().getParameters().get('startURL');
        return Site.login(username, password, startUrl);
    }
    
     global SiteLoginController () {}
    
    @IsTest(SeeAllData=true) global static void testSiteLoginController () {
        // Instantiate a new controller with all parameters in the page
        SiteLoginController controller = new SiteLoginController ();
        controller.username = 'test@salesforce.com';
        controller.password = '123456'; 
                
        System.assertEquals(controller.login(),null);                           
    }    
}