how to get the ip of my Ubuntu instance in AWS

How can I see the public IP address assigned to an EC2 instance, from within (i.e. after connecting) the EC2 instance? I can see the public IP address that is assigned to it, simply by looking in the Management Console.

From AWS document, we can get the public ip address using the following curl command.

$ TOKEN=`curl -X PUT "http://169.254.169.254/latest/api/token" -H "X-aws-ec2-metadata-token-ttl-seconds: 21600"` && curl -H "X-aws-ec2-metadata-token: $TOKEN" -v http://169.254.169.254/latest/meta-data

but looks like it doesn't work.

$ TOKEN=`curl -X PUT "http://169.254.169.254/latest/api/token" -H "X-aws-ec2-metadata-token-ttl-seconds: 21600"` && curl -H "X-aws-ec2-metadata-token: $TOKEN" -v http://169.254.169.254/latest/meta-data
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100    56  100    56    0     0  28000      0 --:--:-- --:--:-- --:--:-- 56000
*   Trying 169.254.169.254:80...
* TCP_NODELAY set
* Connected to 169.254.169.254 (169.254.169.254) port 80 (#0)
> GET /latest/meta-data HTTP/1.1
> Host: 169.254.169.254
> User-Agent: curl/7.68.0
> Accept: */*
> X-aws-ec2-metadata-token: AQAAAEKVNCUB3KPoodSB0SFUkkn1aSah2MRUxAVQQx_3SeVBllVoFA==
> 
* Mark bundle as not supporting multiuse
* HTTP 1.0, assume close after body
< HTTP/1.0 200 OK
< Accept-Ranges: bytes
< Content-Length: 324
< Content-Type: text/plain
< Date: Tue, 29 Nov 2022 11:29:43 GMT
< Last-Modified: Wed, 23 Nov 2022 18:36:36 GMT
< X-Aws-Ec2-Metadata-Token-Ttl-Seconds: 21600
< Connection: close
< Server: EC2ws
< 
ami-id
ami-launch-index
ami-manifest-path
auth-identity-credentials/
block-device-mapping/
events/
hostname
iam/
identity-credentials/
instance-action
instance-id
instance-life-cycle
instance-type
local-hostname
local-ipv4
mac
metrics/
network/
placement/
profile
public-keys/
reservation-id
security-groups
services/

Any idea how to get the public ip in EC2 instance?

• For private ip address, you can use Ubuntu command like ifconfig or ip addr command to get it. You can also get the ip address for one specific interface with ip addr show dev <interface name>. More info is explained in this post.

  Here is one example:

  $ ip addr  show dev eth0
  2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 9001 qdisc mq state UP group default qlen 1000
      link/ether 02:3f:4d:eb:52:e7 brd ff:ff:ff:ff:ff:ff
      inet 10.1.0.143/24 brd 10.1.0.255 scope global dynamic noprefixroute eth0
         valid_lft 2166sec preferred_lft 2166sec
  

• For public ip address, you can use aws ec2 command. This command will list the details about your instance like disk info, network interface, aws instance type etc. It is very helpful to get more info about your ec2 instance. You might need install awscli before run this command. The following example will list the instance details based on the private ip address filter.

  aws ec2 describe-instances --filters Name=private-ip-address,Values=10.6.10.199
  

I generally use an external service for this. If you would like the IPv4 address for your server to be recorded in a file named ip_v4.txt, you can do this:

wget -q -nv https://api.ipify.org -O ip_v4.txt

If you would like the IPv6 address in a file named ip_v6.txt, you can do this:

wget -q -nv https://api64.ipify.org -O ip_v6.txt

Naturally, you may need to customise this to output the address in the manner that you'd like.

This gets around the issues of using Amazon's various APIs and provides something a little more universal that can work on any Linux-based server, regardless of where it is hosted.