Deploying an Amazon MySQL RDS Instance

by Semir H.


If you find this tutorial useful, please consider making a donation to support future work like this:

Thank you :)

Preparation:

Decide in which Region you will create this.
Decide on the DB Engine (MySQL or Oracle).
For this tutorial I will use the following:

Multi AZ Deployment = Yes
Allocated Storage = 5 GB (minimum - good enough for this tutorial)
DB Instance Identifier = TestDB-Inst
Master Username = dbadmin
Password = whatever you want

Procedure:

Log into your Amazon Web Services (AWS) Management Console. Go to the Amazon RDS tab. Pick your Region. Click on “Launch DB Instance”.
In the “Engine Selection” pick MySQL and click on “Select”.
Fill in the “DB Instance Details” as per your needs. I’ll use the details I put down above. Click on “Continue”
Example:

On the “Additional Configuration” part leave everything at defaults (no need to put a DB name now). Click on “Continue”.

On the “Management Options” pick your Backup Retention Period (e.g. 1 day), Backup Window and Maintenance Window. Click on “Continue”.

Review your settings and if you are happy, launch the DB Instance.

DB Security Groups (connecting EC2 to RDS):

To make sure a particular EC2 Instance (in my case an Ubuntu Linux one) can connect to the Amazon RDS MySQL Instance we just created we need to create or modify an existing DB Security Group. I’ll just modify the default one.
Go to Amazon RDS tab and click on the “DB Security Groups” link.
Click on the “default” DB Security Group.
Under “Connection Type” pick “EC2 Security Group”.
Put in your Security Group name (in my case it was “linux sec grp”) and the AWS Account ID of the AWS account where this EC2 Security Group is. The number is a 12 digit number without any dashes.
Click on “Add”. If all goes well you should see that the connection you just defined will be authorised. Here’s an example (with my personal details blacked out):

This will essentially let any EC2 Instance (my Linux Instances) that are controlled by my “Linux Sec Grp” Security Group be able to communicate with my new MySQL RDS Instance.

To connect to the new MySQL Amazon RDS Instance (TestDB-Inst) we’ll need to find the Endpoint address. We do that by clicking on the DB Instance and looking under its Description. In my case it is “testdb-inst.cheuhkpk9v6o.ap-southeast-1.rds.amazonaws.com”.

Testing connecting:

# mysql -h testdb-inst.cheuhkpk9v6o.ap-southeast-1.rds.amazonaws.com -u dbadmin -p

Enter the password and there you go, you are now connected to your MySQL Instance.
You may now create databases for your projects.

Attach additional Volume(s) to AWS EC2 Linux (Ubuntu) Instance(s)

by Semir H.

This quick tutorial will show you how to create a new EBS volume in AWS EC2 and attach it to an existing EBS backed Linux (Ubuntu) EC2 Instance.

If you find this tutorial useful, please consider making a donation to support future work like this:

Thank you :)

Preparation:

Please note down which Availability Zone (AZ) your existing Instance is in. You will need to create the new volume in the same AZ. Also note down the Instance identifier (starts with “i”) for easier identification later.
Please also schedule some downtime for your Instance (if it is an important one) as you’ll need to shut it off while the volume is attached and it will need to be restarted at least once for testing.

Procedure:

As an example I have an Ubuntu Instance here with 8 GB of disk space that comes with the Ubuntu EC2 AMIs.

To create a new volume to add to the Instance go to Volumes section of the Amazon EC2 portion in the AWS Management Console. Click on “Create Volume”.

Fill in the desired size of the Volume (my example is 20 GB) and make sure you pick the correct AZ (same as where the Instance you will attach this to is). Ignore the Snapshot. Click on “Yes, Create” to make the Volume.

Once it is created you should right-click on it and select “Attach Volume”.
Select the correct Instance and put in the device name. The default for the Device will usually do.
Click on “Yes, Attach” to proceed.
Example:

After a bit you should see the Volume listed at attached to your Instance. Here’s an example of the original 8 GB Volume and the new 20 GB Volume attached to the same Instance:

Now go back to your Instance and start it up. Log in and check if the new Volume can be seen. The quickest way of doing it is to execute “fdisk -l” as a privileged user. The example below shows the original 8 GB and the new 20 GB device.

Of course, the new Volume is unusable in this state so we’ll need to create a mount point for it, create a file system for it and mount it. We’ll also make sure it auto-mounts after the box is restarted in the future.

First, we’ll create a new mount point. “mkdir /newdisk”. This will create a folder “newdisk” in the root of the current system.

We’ll then run cfdisk on the /dev/xvdf device to create a usable partition. Please see the cfdisk documentation for more details. I basically create a new primary partition (called xvdf1) using all the available space.
Then, we’ll create a file system for the new partition. Let’s go with ext4. Command is “mkfs.ext4 /dev/xvdf1”.  You can now mount the partition under the folder we created earlier. Command is “mount /dev/xvdf1 /newdisk/”. Please check you can write to it.
Next, we’ll make sure the new partition is auto-mounted on system start-up. We do this in the /etc/fstab file. Just add the following line (no quotes):

“/dev/xvdf1      /newdisk        ext4    defaults        1       2”

Please see the fstab documentation for options. You may want to use different options for your own environment.
Save the file. Restart the system to test it. When you log back in you should see the new partition mounted in the correct folder and you should be able to write to it.
Example (df -h):

How to change AWS EC2 Security Group of an existing Instance

By Semir H.


If you find this tutorial useful, please consider making a donation to support future work like this:

Thank you :)

Scenario:

You have a few pre-made Security Groups and one of your Instances needs to change from one to another.

Solution:

AWS EC2 does not have a way to easily switch these. You basically have to clone the Instance into an AMI and then deploy a new Instance out of that AMI, taking care to associate the new Instance with the desired Security Group at the time of creation.
You can delete the AMI and the associated Snapshot, if you desire so.

Process:

Create a Security Group with your desired port settings.

Clone your Instance by right clicking on it and choosing to create an Image (EBS AMI). It is best if the original Instance is turned off so that no data is lost.

After a bit of time your new AMI should be visible in the AMIs section. Please make sure you’re in the correct Region.

Right-click on your new AMI and pick “Launch Instance”.

Use the “Request Instance Wizard” to select settings you wish but please make sure you select the correct Security Group during this process.
You may also take this opportunity to change your Key Pair.

Finish the wizard and launch the Instance.

You should now see that the new Instance has the new Security Group associated with it.
Log into your new Instance and confirm that no data is missing.

Cleanup:

Once you are sure no data is missing and that you will not need your original Instance or the resulting AMI then you can delete both.
Also delete the Snapshot that was made during the cloning process.

AWS EC2 Security Group (Firewall) Design and Creation

By Semir H.

This quick tutorial will show you how to open up some common ports on the AWS EC2 Firewalls, otherwise known as Security Groups. Please note that you should think about the Security Group design before you create Amazon Web Services (AWS) EC2 Instances. Once created and associated with a Security Group, there is no easy way (but there is a way) to associate an Instance with a different Security Group. I’ll show you how you can do it in another tutorial.

Let’s say we want to open TCP port 22 for SSH access to a Linux machine, ports 80 (HTTP) and 443 (HTTPS) for web access and port 10000 for Webmin. We want the HTTP/S ports to be open to anyone on the Internet but we want to restrict access over SSH and Webmin ports to a certain IP. The IP we will restrict it to will be 1.2.3.4 (obviously made up).


If you find this tutorial useful, please consider making a donation to support future work like this:

Thank you :)

Procedure:

Log into your Amazon Web Service (AWS) Management Console.

Navigate to Security Groups in the NETWORKING & SECURITY section.

Click on the “Create Security Group” button.

Give it a Name and a Description. Leave the VPC option as “No VPC”. Click on “Yes, Create”. Example:

Select the newly created Security Group and click on the Inbound tab at the bottom of the page to create new rules.

HTTP(S) and SSH can be pre-selected from the “Create a new rule” drop-down box. Webmin port will be the custom option.

Finally, click on “Apply Rule Changes”.

To put in a single IP as the Source you need to put the netmask as /32.
So our fake 1.2.3.4 address will be entered as 1.2.3.4/32

As you add the rules they will appear to the right of the rule creation area. You will see a message saying “Your changes have not been applied yet” until you apply them. To apply them just hit the “Apply Rule Changes” button.

Here’s what our finished example looks like: