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 meth开发者_开发百科od 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/.$//'

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/.

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']"

Easiest I found so far

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

You can use ec2-metadata:

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

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.

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

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'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

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.

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