Find region from within an EC2 instance

Is there a way to look up the region of an instance from within the instance?

I'm looking for something similar to the method of finding the instance id.

That URL (http://169.254.169.254/latest/dynamic/instance-identity/document) doesn't appear to work anymore. I get a 404 when I tried to use it. I have the following code which seems to work though:

EC2_AVAIL_ZONE=`curl -s http://169.254.169.254/latest/meta-data/placement/availability-zone`
EC2_REGION="`echo \"$EC2_AVAIL_ZONE\" | sed 's/[a-z]$//'`"

There is one more way of achieving that:

REGION=`curl http://169.254.169.254/latest/dynamic/instance-identity/document|grep region|awk -F\" '{print $4}'`

echo $REGION

us-east-1

If you are OK with using jq, you can run the following:

curl -s http://169.254.169.254/latest/dynamic/instance-identity/document | jq .region -r

I guess it's the cleanest way.

ec2-metadata --availability-zone | sed 's/.$//'

For debian based systems, the command is without dash.

ec2metadata --availability-zone | sed 's/.$//'

If you want to avoid regular expression, here's a one-liner you can do with Python:

curl -s http://169.254.169.254/latest/dynamic/instance-identity/document | python -c "import json,sys; print json.loads(sys.stdin.read())['region']"

You can use ec2-metadata:

ec2-metadata -z | grep -Po "(us|sa|eu|ap)-(north|south|central)?(east|west)?-[0-9]+"

Easiest I found so far

 curl -s 169.254.169.254/latest/meta-data/placement/availability-zone | sed 's/.$//'

At some point since most of these answers have been posted, AWS did the reasonable thing and implemented a new path: latest/meta-data/placement/region.

This means getting the region should be as simple as

curl http://169.254.169.254/latest/meta-data/placement/region

EDIT: It's also probably worth mentioning that this endpoint was made available in the 2019-10-01 release of the metadata API. Make sure your instance supports that version or later before using this by checking http://169.254.169.254/.

very simple one liner

export AVAILABILITY_ZONE=`wget -qO- http://instance-data/latest/meta-data/placement/availability-zone`
export REGION_ID=${AVAILABILITY_ZONE:0:${#AVAILABILITY_ZONE} - 1}

Get the region from the availability zone, strip off the last letter of it.

ec2-metadata -z | awk '{print $2}' | sed 's/[a-z]$//'

If you're able to use the AWS Java SDK, there is now a method that will return the current region name (such as "us-east-1", "eu-west-1"):

http://docs.aws.amazon.com/AWSJavaSDK/latest/javadoc/com/amazonaws/regions/Regions.html#getCurrentRegion()

This is the cleanest solution I found:

curl -s http://169.254.169.254/latest/dynamic/instance-identity/document |sed -n 's/  "region" : "\(.*\)"/\1/p'

E.g.,

export REGION=$(curl -s http://169.254.169.254/latest/dynamic/instance-identity/document |sed -n 's/  "region" : "\(.*\)"/\1/p')

• Doesn't make an API call, uses EC2 instance meta-data
• Only uses curl, and basic sed, so no dependencies on SDKs or tools not likely to be installed.
• Doesn't attempt to parse the Availability Zone name, so no worries if AWS changes AZ/Region name format

Thanks to https://unix.stackexchange.com/a/144330/135640, with bash 4.2+ we can just strip the last char from the availability zone:

$ region=`curl -s 169.254.169.254/latest/meta-data/placement/availability-zone`
$ region=${region::-1}
$ echo $region
us-east-1

This assumes AWS continues to use a single character for availability zones appended to the region.

2 liner that works as long as you are using ec2.internal as your search domain:

az=$(curl -s http://instance-data/latest/meta-data/placement/availability-zone)
region=${az:0:${#az} - 1}

For anyone wanting to do this with good ol powershell

$var = (curl http://169.254.169.254/latest/dynamic/instance-identity/document | Select-String-Pattern "Zone" | ConvertFrom-Json | Select-Object -ExpandProperty "region")
echo $var

Or don't make Ubuntu or this tool a requirement and simply do:

: "${EBS_VOLUME_AVAILABILITY_ZONE:=$(curl -s http://169.254.169.254/latest/meta-data/placement/availability-zone)}"
: ${EBS_VOLUME_REGION:="${EBS_VOLUME_AVAILABILITY_ZONE%%*([![:digit:]])}"}

This works for eu-central-1 as well as the various letter zones. (I don't have enough rep to reply to the sed answer above)

ec2-metadata --availability-zone | sed 's/[a-z]$//'

If you work with json - use right tools. jq much powerful in this case.

# curl -s curl -s http://169.254.169.254/latest/dynamic/instance-identity/document | jq -r '.region'
eu-west-1

If you're running on windows, you can use this powershell one-liner:

$region=(Invoke-RestMethod "http://169.254.169.254/latest/dynamic/instance-identity/document").region

For finding out information about the EC2 you are logged into, you can use the ec2-metadata tool.

You can install the tool by following this link. After installing the tool, you can run

# ec2-metadata -z

to find out the region.

This tools comes installed with the latest (10.10) Ubuntu AMIs,

If you are looking to get region using JS, this should work :

meta.request("/latest/meta-data/placement/availability-zone",function(err,data){
        if(err)
                console.log(err);
        else{
                console.log(data);
                str = data.substring(0, data.length - 1);
                AWS.config.update({region:str});
                ec2 = new AWS.EC2();
            }
     });

This was the mapping found from AWS DOCS, in response to metadata API call, just trim the last character should work.

  eu-west-1a :eu-west-1
  eu-west-1b :eu-west-1
  eu-west-1c :eu-west-1
  us-east-1a :us-east-1
  us-east-1b :us-east-1
  us-east-1c :us-east-1
  us-east-1d :us-east-1
  ap-northeast-1a :ap-northeast-1
  ap-northeast-1b :ap-northeast-1
  us-west-1a :us-west-1
  us-west-1b :us-west-1
  us-west-1c :us-west-1
  ap-southeast-1a :ap-southeast-1
  ap-southeast-1b :ap-southeast-1

Was also looking for a solution to find region from the instance and here is my pure Bash solution:

az=$(curl -s http://169.254.169.254/latest/meta-data/placement/availability-zone)
region=${az:0:${#az}-1}

unless there are regions where AZ has more than two letters, which I'm not aware of.

If you are looking for a simpler way to do it, you can look at /etc/resolv.conf and find a line like "search us-west-2.compute.internal". For example:

$ grep "^search" /etc/resolv.conf | sed "s:.* ::; s:\..*::"
us-west-2

ec2metadata (no dash) is the current command to provide you all the aws hosting info about your ec2 box. this is the most elegant and secure approach. (ec2-metadata is the old, no longer valid command.)

A method using only egrep, which should work on most any linux instance spun up without having to install any extra tooling. I tested this against a list of all current AWS regions and they all match.

curl http://169.254.169.254/latest/meta-data/placement/availability-zone | egrep -o '(\w)+-(\w)+-[0-9]'

Explanation of the REGEX:

• "(\w)+" This matches any number of letters
• "-" matches only a single dash
• "[0-9]" matches any 1 number

If you want this into a variable do:

region=$(curl http://169.254.169.254/latest/meta-data/placement/availability-zone | egrep -o '(\w)+-(\w)+-[0-9]')

For the sed and curl solution it looks like format has changed a bit. For me works

curl -s http://169.254.169.254/latest/dynamic/instance-identity/document | sed -n 's/ "region" : "\(.*\)"[,]/\1/p'

All this no longer works on AMI Linux 2... I found this offline (undocumented) approach:

REGION=`cat /opt/elasticbeanstalk/config/ebenvinfo/region`
echo $REGION

# output example:
us-east-1

If you are using IMDSv2, you'll need the token first.

Here's an example using bash, which also depends on curl:

function get-aws-region() {
  imdsv2_token="$(
    curl -s -X PUT "http://169.254.169.254/latest/api/token" \
            -H "X-aws-ec2-metadata-token-ttl-seconds: 1"
  )"
  curl -s http://169.254.169.254/latest/meta-data/placement/region \
         -H "X-aws-ec2-metadata-token: $imdsv2_token"
}

This gets a very short-lived token and uses it to get the region.