AWS: How to Configure Outward Facing Host? - amazon-web-services

I have an Amazon EC2 instance. Lets say my public DNS is
ec2-54-200-54-33.us-west-2.compute.amazonaws.com
I am using this instance to help develop a new website, and I want to map the host
dev01.company.com
to this instance. How do I do that? I think there are at most 2 steps, including mapping the host with the registrar, and possibly something in Amazon. What are the steps I would need to do to accomplish this? How do I take all the details of my instance and map the hosts as metioned above?

1) Assign an Elastic IP to your EC2 instance (you can do that through the AWS Management Console).
2) Add an "A" record for "dev01" pointing to that IP, using the tool provided by your domain registrar.

Amazon recommends using a CNAME record instead
dev01.company.com CNAME ec2-54-200-54-33.us-west-2.compute.amazonaws.com
You will also need to open up whatever ports you need accessible to the security group of the EC2 instance (ie TCP 80 open to 0.0.0.0/0 > this will open to everyone)

Related

AWS EC2 instance "This site can't be reached", though I do have the ports 80 and 443 open

I have been looking for help with this problem, and the answers just say to add inbound rules to the security group. Well, I have done those and I am still unable to access my website from the public DNS (just putting that into the url box and navigating to it). There are multiple port 22 inbound rules for the people accessing my server, and the outbound rule is just "All traffic".
I've had this problem running Wordpress on EC2 instances. Things I'd try:
Access the instance via ssh. Check out https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/AccessingInstancesLinux.html
If you're accessing through ssh, maybe it's because your disk is full. To check this you can run df -h on your Amazon EC2 server.
I tried accessing my newly setup AWS EC2 Instance and I had this same issue, I later realised I was accessing the public DNS via HTTPS which had not been set up. when I changed the url to use HTTP it worked. Ensure to configure HTTP in the security group.

AWS - Can I launch nodes under a DNS domain (Auto Scale Group)?

Use Case
I'm working on an application that uses Presto, and for Presto, I have to set up HTTPS traffic internally (for security compliance reasons).
For this, I preferably need the nodes' FQDN to be in the same domain. E.g. myhost1.mydomain.com, myhost2.mydomain.com.
My Question
AWS automatically gives a FQDN like ip-10-20-30-40.ec2.internal. So, my question is:
Is there a way I can have a new node automatically be created with a FQDN like myhost1.mydomain.com? I know I can create internal "hosted zones" and DNS records for my hosts pretty easily, but I can't figure out how to make that the default domain for a new host.
Also, just FYI, I'm doing this for an auto-scale group; but I suspect that's irrelevant.
When the Amazon EC2 starts, it can run a script passed in via User Data.
You could code this script to create a CNAME record in Amazon Route 53 that points to the IP address of the instance.
I'm not sure how you'd necessarily determine the number within the name, so you could just create a random name. Also, it might be tricky to remove the CNAME entry when the instance is terminated. One way to both assign and remove the record would be to use Amazon EC2 Auto Scaling Lifecycle Hooks, which allows code to be triggered outside of the instance itself. It's more complex but would be fully effective.
I'm not familiar with Presto, but here's a couple of ideas.
First, if you are using an AWS managed load balancer, you can enable HTTPS between it and the instance using self-signed cert: the load balancer will NOT validate the cert, so your connection will be secure.
If that's not what you need, take a look at DHCP option sets for your VPC - I believe you can set your own domain name, rather than use the default ec2.internal.

Why do you need to change the Hostname of your EC2 instance?

There is a topic in EC2 documentation Changing the System Hostname. Why does one need to change it? Just for fun? Just to have some nice shell prompt?
// change this
ubuntu#ip-123-12-1-231 ~ $
// to this?
ubuntu#my-beautiful-hostname ~ $
I'm learning how AWS DNS work, where my EC2's DNS lives that resolves a default Public DNS name to Public IP address of my instance
Public DNS: ec2-xx-xx-xxx-xx.ap-southeast-2.compute.amazonaws.com
Public IP: xx-xx-xxx-xx
And how can I host multiple apps with real domain names (example1.com, example2.com, so on) in one EC2 instance, how to modify and manage DNS. And actually I don't know what to read about it in docs, and read everything related to hostnames and DNS, and found this topic Changing the System Hostname and don't understand why would one want to change a hostname and if it can be valuable info for me.
UPD:
And now a real a practical question for those specimens who like closing questions quietly.
Where does a DNS live in EC2 instance? How is Public DNS mapped to Public IP? Where is that record in my EC2 Ubuntu instance? Is Route53 involved in it?
Where does a DNS live in EC2 instance?
It doesn't, DNS resolution use by the server is set in /etc/resolv.conf and /etc/nsswitch.conf. The hostname domain name for that server is set (Redhat derived systems) in /etc/sysconfig/network
How is Public DNS mapped to Public IP?
With a DNS record
Where is that record in my EC2 Ubuntu instance?
In the DNS for the domain that you have attached it to
Is Route53 involved in it?
Only if you are using Route53 for DNS
EC2 DNS location (source):
In EC2-Classic, the Amazon DNS server is located at 172.16.0.23.
In EC2-VPC, the Amazon DNS server is located at the base of your VPC network range plus two.
For more information, see Amazon DNS Server in the Amazon VPC User Guide
Well i had the same issue as you did and someone replied me this
It isn't a huge deal if you are just running a single server, mostly
to help you identify a server with local networking. Some things like
mail servers will use your hostname unless you specify otherwise.
This is an example of somewhere I saw that done
My original query
why do some people set hostname and some dont? whats the use?
hostnamectl set-hostname

On aws able to access yourdomain.com but not able to access http://www.yourdomain.com.?

I have done the configuration on AWS I'm able to access yourdomain.com(For example) but not able to access http://www.yourdomain.com?
I'm using Amazon EC2 virtual server cloud and route 53 hosted zones.
As Mark B said, your question lacks a lot of the necessary details, however I will answer based on a few assumptions.
1) I'm assuming that your instance is publicly accessible
2) I'm assuming that your instance is not inside a VPC
3) I'm assuming that your instance is not behind a load balancer
First, go to your EC2 instance and copy the public DNS of your instance. IP's can change over time, therefore best practice is to use the public DNS as the value.
Next go to Route 53, and go to the Hosted Zone for your domain and click the blue button that says "Create Record Set".
In the name field put: www
In the type, select: CNAME
In the value field you'll paste the DNS for the EC2 instance
Click create.
If you've done this right, and your security groups are correctly configured, you should be able to now visit your site using www.yourdomain.com.
Below solution worked for me.
Name-www.yourdomain.com Type-CNAME Value-yourdomain.com. (Dot is important)

AWS CPANEL WHM - IP Address and DNS Settings on new accounts

I've (hopefully) successfully set up Cpanel on AWS with clustering following the instructions: https://blog.cpanel.com/part-1-how-i-built-a-cpanel-hosting-environment-on-amazon-aws/
I've been using CPanel/WHM on a dedicated server for a few years before I set up this new Cpanel installation on AWS. My issues comes from how new accounts are set up differently on a dedicated server vs the AWS way.
My first issue:
When I created a new account on my dedicated WHM, I was provided IP Addresses from the server farm that I assigned to newly created accounts. Once assigned, I can access the site with either the IP or the domain name. Now with this new AWS way, there's no info in the tutorials about how I obtain new IP Addresses. I tried adding a new local IP like 10.0.0.30 (because it says it's in NAT mode and use local IP) and assigning this as a dedicated IP to the newly created accounts but I don't understand how anybody can access the site through that IP since its a local IP. So how do I access the domain through custom IP and domain like I did before? I must be missing something fundamental.
My second issue:
On my dedicated WHM after I created a new account, I would typically go to DNS Functions -> Edit DNS Zone and edit the zone to customize my nameserver as so:
mynewdomain.com
ns1.mynewdomain.com
ns2.mynewdomain.com
anothersite.com
ns1.anothersite.com
ns2.anothersite.com
thirdsite.com
ns1.thirdsite.com
ns2.thirdsite.com
and then in my register I would add these custom nameservers into the register and point them to the dedicated IPs of each domain. But with the AWS way, the only way I was able to set this up was to use the new cluster nameservers as the nameserver for ALL accounts in this new WHM installation.
Like this:
mynewdomain.com
ns1.awsnameserver.com
ns2.awsnameserver.com
anothersite.com
ns1.awsnameserver.com
ns2.awsnameserver.com
thirdsite.com
ns1.awsnameserver.com
ns2.awsnameserver.com
Is this the correct / the only way I can set up accounts now through this set up?
Is there a way to have custom nameservers names like I did in dedicated WHM?
In my case, I have a DNS server outside of Amazon so I'm not sure it would answer your question but it might lead you somewhere.
First to figure out what your public IP is you can:
Go to the AWS console and look at the instance detail of your server.
Look for the "endpoint". This points to your public address so you can do a PING or NSLOOKUP to find out what your IP is.
However, AWS does not recommend you hard-coding the public address as it could change. So what I did instead was to create a CNAME in my DNS that points to that "endpoint".
I hope that helps.