Reset password flow

My email account is a skeleton key to anything online I’ve signed up for. If I forget a password, I can reset it. Implementing this feature for a web app takes just a few steps.

When users enter an incorrect password, I prompt them to reset it.

incorrect password warning

Clicking the reset link calls a “forgot password” back-end service.

$(document).on("click",".reset-pw-cta", function(){
	var email = $(this).attr("data");
	$.ajax({
		url:"/service-layer/user-service.php?method=forgotPw&email="+email,
		complete:function(response){
			console.log(response.responseText)
			window.showStatusMessage("A password reset email as been sent to " + email);
		}
	})
});

A token is created in our ‘password recovery’ database table. That token is related back to an account record.

password recovery database table

As a security practice, recovery tokens are deleted nightly by a cron job.

An email is then sent containing a “reset password” link embedded with the token. AWS SES and PHPMailer is used to send that message.

function forgotPw(){
	$email = $this->email;
	$row = $this->row;
	$number_of_rows = $this->number_of_rows;
	$conn = $this->connection;
	if($number_of_rows > 0){
		$this->emailFound = 1;
		$userid = $row['ID'];
		$this->userid = $userid;

		//create reset token
		$timestamp = time();
		$expire_date = time() + 24*60*60;
		$token_key = md5($timestamp.md5($email));
		$statement = $conn->prepare("INSERT INTO `passwordrecovery` (userid, token, expire_date) VALUES (:userid, :token, :expire_date)");
		$statement->bindParam(':userid', $userid);
		$statement->bindParam(':token', $token_key);
		$statement->bindParam(':expire_date', $expire_date);
		$statement->execute();

		//send email via amazon ses
		include 'send-email-service.php';	
		$SendEmailService = new SendEmailService();

		$reset_url = 'https://www.bjjtracker.com/reset-pw.php?token='.$token_key;
	        $subject = 'Reset your password.';
	        $body    = 'Click here to reset your password: <a href="'.$reset_url.'">'. $reset_url .'</a>';
	        $altBody = 'Click here to reset your password: ' . $reset_url;
	        $this->status = $SendEmailService -> sendEmail($subject, $body, $altBody, $email);


	}else{
		$this->emailFound = 0;
	}
}

That link navigates to a page with a “reset password” form.

reset password form

Upon submission the new password and embedded token are passed along to the server.

$(document).ready(function() {
    $(".reset-button").click(function(){
      var newPassword = $(".password-reset-input").val();
      if(newPassword.length < 1){
        var notifications = new UINotifications();
        notifications.showStatusMessage("Please don't leave that blank :( ");
        return;
      }
      var data = $(".resetpw-form").serialize();
      $.ajax({
        url: "/service-layer/user-service.php?method=resetPw&token=<?php echo $_GET['token']; ?>",
        method: "POST",
        data: data,
        complete: function(response){
          // console.log(response);
          window.location = "/";
        }
      });
    });
    $("input").keypress(function(e) {
      if(e.which == 13) {
        e.preventDefault();
          $(".reset-button").click();
      }
  });
  

});

The correct recovery record is selected by using the token value. That provides the user ID of the account that we want to update. The token should be deleted once the database is updated.

function resetPw(){
	$conn = $this->connection;
	$token = $_GET['token'];
	$password = $_POST['password'];
	$passwordHash = password_hash($password, PASSWORD_DEFAULT);
	$statement = $conn->prepare("SELECT * FROM `passwordrecovery` where token = ?");
	$statement->execute(array($token));
	$row = $statement->fetch(PDO::FETCH_ASSOC);
	$userid = $row['userid'];

	$update_statement = $conn->prepare("UPDATE `users` SET password = ? where ID = ?");
	$update_statement->execute(array($passwordHash, $userid));

	$delete_statement = $conn->prepare("DELETE FROM `passwordrecovery` where token = ?");
	$delete_statement->execute(array($token));
}

This is a secure and user-friendly workflow to allow users to reset their passwords.

Error establishing connection to database – WordPress solution

solutions for wordpress database errors

A crashed database is a problem I’ve encountered across multiple WordPress websites. When trying to load the site you’re faced with a dreaded “Error establishing a database connection” message. Restarting the DB service usually clears things up. But, sometimes it won’t restart at all – which is why I started automating nightly data dumps to an S3 bucket.

Recently, one particular site kept going down unusually often. I assumed it was happening due to low computing resources on the EC2 t3.micro instance. I decide to spin up a a new box with more RAM (t3.small) and migrate the entire WordPress setup.

Since I couldn’t be sure of what was causing the issue, I needed a way to monitor the health of my WordPress websites. I decided to write code that would periodically ping the site, and if it is down send an email alert and attempt to restart the database.

warning message when a website can't connect to the database

The first challenge was determining the status of the database. Even if it crashed, my site would still return a 200 OK response. I figured I could use cURL to get the homepage content, and then strip out any HTML tags to check the text output. If the text did match the error message, I could take further action.

Next, I needed to programmatically restart MySql. This is the command I run to do it manually: sudo service mariadb restart 

After doing some research, I found that I could use shell_exec() to run it from my PHP code. Unfortunately, Apache wouldn’t let the (non-password using) web server user execute that without special authorization. I moved that command to its own restart-db.sh file, and allowed my code to run it by adding this to the visudo file: apache ALL=NOPASSWD: /var/www/html/restart-db.sh

I also needed to make the file executable by adjusting permissions: sudo chmod +x /var/www/html/restart-db.sh

Once those pieces were configured, my code would work:

<?php

$url = "http://www.antpace.com/blog";
$curl_connection = curl_init();

curl_setopt($curl_connection, CURLOPT_URL, $url);

curl_setopt($curl_connection, CURLOPT_RETURNTRANSFER, true);
$curl_response = curl_exec($curl_connection);
$plain_text = strip_tags($curl_response);

if(strpos($plain_text, "Error establishing a database connection") !== false){
	echo "The DB is down.";
        
        //restart the database
        shell_exec('sudo /var/www/html/restart-db.sh');
        
        //send notification email
        import 'send-email.php';
        send_email();
}else{
	echo "The DB is healthy.";
}

?>

You can read more about how to send a notification email in another post that I wrote on this blog.

Create the cron job

A cron job is a scheduled task in Linux that runs at set times. For my PHP code to effectively monitor the health of the database, it needs to run often. I decided to execute it every five minutes. Below are three shell commands to create a cron job.

The first creates the cron file for the root user:

sudo touch /var/spool/cron/root

The next appends my cron command to that file:

echo "*/5 * * * * sudo wget -q 127.0.0.1/check-db-health.php" | sudo tee -a /var/spool/cron/root

And, the last sets the cron software to listen for that file:

sudo crontab /var/spool/cron/root

Alternatively, you can create, edit, and set the cron file directly by running sudo crontab -e . The contents of the cron file can be confirmed by running sudo crontab -l .

 

Migrate a WordPress site to AWS

WordPress migration

In a previous article I discussed launching a website on AWS. The project was framed as transferring a static site from another hosting provider. This post will extend that to migrating a dynamic WordPress site with existing content.

Install WordPress

After following the steps to launch your website to a new AWS EC2 instance, you’ll be able to connect via sFTP. I use FileZilla as my client. You’ll need the hostname (public DNS), username (ec2-user in this example), and key file for access. The latest version of WordPress can be downloaded from wordpress.org. Once connected to the server, I copy those files to the root web directory for my setup: /var/www/html

Make sure the wp-config.php file has the correct details (username, password) for your database. You should use the same database name from the previous hosting environment.

Data backup and import

It is crucial to be sure we don’t lose any data. I make a MySql dump of the current database and copy the entire wp-content folder to my local machine. I’m careful to not delete or cancel the old server until I am sure the new one is working identically.

After configuring my EC2 instance, I install phpMyAdmin so that I can easily import the sql file.

sudo yum install php-mbstring -y
sudo systemctl restart httpd
sudo systemctl restart php-fpm
cd /var/www/html
wget https://www.phpmyadmin.net/downloads/phpMyAdmin-latest-all-languages.tar.gz
mkdir phpMyAdmin && tar -xvzf phpMyAdmin-latest-all-languages.tar.gz -C phpMyAdmin --strip-components 1
rm phpMyAdmin-latest-all-languages.tar.gz
sudo systemctl start mariadb

The above Linux commands installs the database management software on the root directory of the new web server. It is accessible from a browser via yourdomainname.com/phpMyAdmin. This tool is used to upload the data to the new environment.

phpMyAdmin import screen

Create the database and make sure the name matches what’s in wp-config.php from the last step. Now you’ll be able to upload your .sql file.

Next, I take the wp-content folder that I stored on my computer, and copy it over to the new remote. At this point, the site homepage will load correctly. You might notice other pages won’t resolve, and will produce a 404 “not found” response. That error has to do with certain Apache settings, and can be fixed by tweaking some options.

Server settings

With my setup, I encountered the above issue with page permalinks . WordPress relies on the .htaccess file to route pages/posts with their correct URL slugs. By default, this Apache setup does not allow its settings to be overridden by .htaccess directives. To fix this issue, the httpd.conf file needs to be edited. Mine was located in this directory: /etc/httpd/conf

You’ll need to find (or create) a section that corresponds to the default document root: <Directory “/var/www/html”></Directory>. In that block, they’ll be a AllowOverride command that is set to “None”. That needs to be changed to “All” for our configuration file to work.

apache config settings found in the HTTPD conf file

Final steps

After all the data and content has been transferred, do some smoke-testing. Try out as many pages and features as you can to make sure the new site is working as it should. Make sure you keep a back-up of everything some place secure (I use an S3 bucket). Once satisfied, you can switch your domain’s A records to point at the new box. Since the old and new servers will appear identical, I add a console.log(“new server”) to the header file. That allows me tell when the DNS update has finally resolved. Afterwards, I can safely cancel/decommission the old web hosting package.

Don’t forget to make sure SSL is setup!

Automatic MySQL dump to S3

Automatic MySQL dump to S3

I have had some lousy luck with databases. In 2018, I created a fitness app for martial artists, and quickly gained over a hundred users in the first week. Shortly after, the server stopped resolving and I didn’t know why. I tried restarting it, but that didn’t help. Then, I stopped the EC2 instance from my AWS console. Little did I know, that would wipe the all of the data from that box. Ouch.

Recently, a client let me know that their site wasn’t working. A dreaded “error connecting to the database” message was all that resolved. I’d seen this one before – no sweat. Restarting the database usually does the trick: “sudo service mariadb restart”. The command line barked back at me: “Job for mariadb.service failed because the control process exited with error code.”

Uh-oh.

The database was corrupted. It needed to be deleted and reinstalled. Fortunately, I just happen to have a SQL dump for this site saved on my desktop. This was no way to live – in fear of the whims of servers.

Part of the issue is that I’m running MySQL on the same EC2 instance as the web server.  A more sophisticated architecture would move the database to RDS. This would provide automated backups, patches, and maintenance. It also costs more.

To keep cost low, I decided to automate MySQL dumps and upload to an S3 bucket. S3 storage is cheap ($0.20/GB), and data transfer from EC2 is free.

AWS Setup

The first step was to get things configured in my Amazon Web Services (AWS) console. I created a new S3 bucket. I also created a new IAM user, and added it to a group that included the permission policy “AmazonS3FullAccess”.

AWS policy to allow full S3 access
This policy provides full access to all buckets.

I went to the security credentials for that user, and copied down the access key ID and secret. I would use that info to access my S3 bucket programatically. All of the remaining steps take place from the command line, via SSH, against my server. From a Mac terminal, you could use a command like this to connect to an EC2 instance:

ssh -i /Users/antpace/Documents/keys/myKey.pem ec2-user@ec2-XX-XX-XX.us-west-2.compute.amazonaws.com

Once connected, I installed the software to allow programatic access to AWS:

curl "https://awscli.amazonaws.com/awscli-exe-linux-x86_64.zip" -o "awscliv2.zip"
unzip awscliv2.zip
sudo ./aws/install

Here is the reference for installing the AWS CLI on Linux.

Shell script

Shell scripts are programs that can be run directly by Linux. They’re great for automating tasks. To create the file on my server I ran: “nano backup.sh”. This assumes you already have the nano text editor installed. If not: “sudo yum install nano” (or, “sudo apt install nano”, depending on your Linux flavor).

Below is the full code I used. I’ll explain what each part of it does.

Credit: This code was largely inspired by a post from Marcelo Gornstein.

#!/bin/bash
AWS_ACCESS_KEY_ID=XXX \
AWS_SECRET_ACCESS_KEY=XXX \
S3_BUCKET=myBucketsName \
MYSQL_HOST=localhost \
MYSQL_PORT=3306 \
MYSQL_USER=XXX \
MYSQL_PASS=XXX \
MYSQL_DB=XXX \

cd /tmp
file=${MYSQL_DB}-$(date +%a).sql
mysqldump \
  --host ${MYSQL_HOST} \
  --port ${MYSQL_PORT} \
  -u ${MYSQL_USER} \
  --password="${MYSQL_PASS}" \
  ${MYSQL_DB} > ${file}
if [ "${?}" -eq 0 ]; then
  gzip ${file}
  AWS_ACCESS_KEY_ID=${AWS_ACCESS_KEY_ID} AWS_SECRET_ACCESS_KEY=${AWS_SECRET_ACCESS_KEY} aws s3 cp ${file}.gz s3://${S3_BUCKET}
  rm ${file}.gz
else
  echo "sql dump error"
  exit 1
fi

The first line tells the system what interpreter  to use: “#!/bin/bash”. Bash is a variation of the shell scripting language. The next eight lines are variables that contain details about my AWS S3 bucket, and the MySQL database connection.

After switching to a temporary directory, the filename is built. The name of the file is set to the database’s name plus the day of the week. If that file already exists (from the week previous), it’ll be overwritten.  Next, the sql file is created using mysqldump and the database connection variables from above. Once that operation is complete, then we zip the file, upload it to S3, and delete the zip from our temp folder.

If the mysqldump operation fails, we spit out an error message and exit the program. (Exit code 1 is a general catchall for errors. Anything other than 0 is considered an error. Valid error codes range between 1 and 255.)

Before this shell script can be used, we need to change its file permissions so that it is executable: “chmod +x backup.sh”

After all of this, I ran the file manually, and made sure it worked: “./backup.sh”

Sure enough, I received a success message. I also checked the S3 bucket and made sure the file was there.

S3 file dump

Scheduled Cronjob

The last part is to schedule this script to run every night. To do this, we’ll edit the Linux crontab file: “sudo crontab -e”. This file controls cronjobs – which are scheduled tasks that the system will run at set times.

The file opened in my terminal window using the vim text editor – which is notoriously harder to use than the nano editor we used before.

I had to hit ‘i’ to enter insertion mode. Then I right clicked, and pasted in my cronjob code. Then I pressed the escape key to exit insertion mode. Finally, I typed “wq!” to save my changes and quit.

Remember how crontab works:

minute | hour | day-of-month | month | day-of-week

I set the script to run, every day, at 2:30am:

30 2 * * * sudo /home/ec2-user/backup.sh

And that’s it. I made sure to check the next day to make sure my cronjob worked (it did). Hopefully now, I won’t lose production data ever again!

Request Time Too Skewed (update)

A while after setting this up, I randomly checked my S3 buckets to make sure everything was still working. Although it had been for most of my sites, one had not been backed up in almost 2 months! I shelled into that machine, and tried running the script manually. Sure enough, I received an error: “An error occurred (RequestTimeTooSkewed) when calling the PutObject operation: The difference between the request time and the current time is too large.

I checked the operating system’s current date and time, and it was off by 5 days. I’m not sure how that happened. I fixed it by installing and running “Network Time Protocol”:

sudo yum install ntp
sudo ntpdate ntp.ubuntu.com

After that, I was able to run my backup script successfully, without any S3 errors.

 


Nano text-editor tip I learned along the way:

You can delete chunks of text content using Nano. Use CTRL + Shift + 6 to enter selection mode, move the cursor to expand the block, and press CTRL + K to delete it.