Find region from within an EC2 instance

Question

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.

possible duplicate of [Find out the instance id from within an ec2 machine](http://stackoverflow.com/questions/625644/find-out-the-instance-id-from-within-an-ec2-machine) — Till, Nov 27 '10 at 23:49
Short answer for anyone who don't care about all the shell scripts: get the availability zone from `http://169.254.169.254/latest/meta-data/placement/availability-zone` and remove the last character. — Sarsaparilla, Dec 09 '17 at 19:31
Does this answer your question? [How to get the instance id from within an ec2 instance?](https://stackoverflow.com/questions/625644/how-to-get-the-instance-id-from-within-an-ec2-instance) — dWinder, May 11 '20 at 08:39
For those reading post mid-2020, you can now use `http://169.254.169.254/latest/meta-data/placement/region` — d4nyll, Aug 06 '20 at 03:58

score 157 · Accepted Answer · edited Mar 22 '18 at 15:28

157

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 \"$EC2_AVAIL_ZONE\" | sed 's/[a-z]$//'`"

Hope this helps.

EDIT: Improved sed based on comments

edited Mar 22 '18 at 15:28

Reverend Tim

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answered Mar 16 '12 at 10:33

dannosaur

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This is to be run *inside* the EC2 instance and is powered by AWS's backends. It will not work anywhere else (essentially because that IP is an APIPA). Also there is no way to get this information directly from inside the instance without connecting to a metadata source. This assumes that the 169.254.169.254 API is available, and your script should handle network failures accordingly. `ec2-metadata` is just a wrapper for this API, but essentially does the same thing. – dannosaur Apr 07 '15 at 07:50
1

Is this something documented? Can you explain how you found it? – meawoppl May 18 '15 at 16:48
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In all honesty when I came up with that 2-liner I was just poking about the API looking for anything I could use to identify the correct region. The AWS metadata API is fully documented here: http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-instance-metadata.html – dannosaur May 18 '15 at 18:10
12

Much simpler sed replace command than the one provided for the EC2_REGION: `sed 's/[a-z]$//` – threejeez Aug 13 '15 at 17:48
The IID sure does work, so looking at it is cleaner than this assumption about how amazon will choose zone names. – bmargulies Nov 19 '15 at 00:21
I wonder if the people who can't get 169.254.169.254 to work have accidentally firewalled it. – David Jones Jan 07 '16 at 14:01
Just for the record, I just successfully retrieved a JSON document that included the AZ from `http://169.254.169.254/latest/dynamic/instance-identity/document` in `us-west-2` (Oregon) region. Don't know if it _wasn't_ working, but it definitely _is_ working (for me!) now. – Calrion May 22 '16 at 07:43
2

If this is in a bootscript, the metadata service may not be instantiated yet - if so, wait and try again. I've seen it take 10-15 seconds after boot for the metadata location to become available. – vacri Mar 27 '18 at 03:46
1

You can avoid calling sed `echo "${EC2_AVAIL_ZONE: : -1}"`. In bash 4.2+ you can remove space between two `:`. – kikap May 17 '18 at 19:06
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Alternatively to both `sed` and bashisms, you can use this much more portable substitution: `EC2_REGION=${EC2_AVAIL_ZONE%?}` – mtraceur Jan 22 '19 at 21:13
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Even simpler `sed`: `sed 's/.$/'` because the `.` in regex matches any single last character. – mtraceur Jan 22 '19 at 21:17
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I prefer to remove "only if present" and "only known possibilities" (exactly like the `sed` of dannosaur) like so : `"${EC2_AVAIL_ZONE%[a-z]}"` – Boop May 15 '19 at 14:55
Made a small improvement to make it easier to use in Ansible: `AWS_DEFAULT_REGION=\`curl -s http://169.254.169.254/latest/meta-data/placement/availability-zone | sed 's/[a-z]$//'\`` – Daniel Hajduk Oct 17 '19 at 09:03
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With bash we can use parameter expansion to make the second line more concise and without creating separate processes: `EC2_REGION=${EC2_AVAIL_ZONE%[a-z]}` – Fabian Ritzmann May 26 '20 at 08:24

score 87 · Answer 2 · edited Aug 02 '12 at 19:41

87

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

edited Aug 02 '12 at 19:41

Fluffy

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answered Feb 13 '12 at 15:53

mgarman

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Should this work in any region/az (and on any AMI)? I'm getting `404 - Not Found` trying to `GET` that URL from a machine in `us-east-1a`. – Adam Monsen Jun 21 '12 at 06:02
@AdamMonsen perhaps it was a transient error. I'm on us-east-1a and it works great. – Florin Andrei Mar 12 '14 at 19:19
Thanks @FlorinAndrei. Works for me now too. – Adam Monsen Mar 13 '14 at 16:44
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With jq: `curl -s http://169.254.169.254/latest/dynamic/instance-identity/document | jq -r .region` – Yaron Jun 17 '14 at 12:08
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With awk: ```curl -s http://169.254.169.254/latest/dynamic/instance-identity/document | awk -F\" '/region/ {print $4}'``` – Yaron Aug 04 '14 at 09:23
This is not secure or safe to rely on. – chicks Apr 03 '15 at 19:54

score 42 · Answer 3 · edited Dec 29 '15 at 15:03

42

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.

edited Dec 29 '15 at 15:03

XDR

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answered Oct 15 '15 at 12:01

Ilya Sher

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score 36 · Answer 4 · edited Jan 16 '20 at 08:13

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

For debian based systems, the command is without dash.

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

edited Jan 16 '20 at 08:13

kontinuity

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answered Jun 16 '16 at 14:48

Jose Alban

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Get pure string with only the region name: `ec2-metadata --availability-zone | sed 's/placement: $.*$.$/\1/'` – nahsh Jun 06 '18 at 11:58
`ec2-metadata` doesn't seem to be something that's available by default - can you include installation instructions? – Tim Malone Apr 17 '19 at 03:39

score 25 · Answer 5 · answered Jul 26 '16 at 05:36

25

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']"

answered Jul 26 '16 at 05:36

Jaeyoung Chun

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This answer should be higher! – Kostas Demiris Sep 21 '16 at 09:15
@KostasDemiris I agree, much rather read the value in from the JSON structure than a regular expression. – lasec0203 Aug 15 '17 at 01:58
1

I agree this seems to be the best way to do it if you don't have jq installed. You would really expect AWS to expose this as something like http://169.254.169.254/latest/meta-data/placement/region ... – Krenair Jan 22 '18 at 13:21

Daniel Kuppitz · Answer 6 · 2015-04-07T08:23:52.883

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You can use ec2-metadata:

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

edited Apr 07 '15 at 08:23

answered Sep 02 '12 at 14:50

Daniel Kuppitz

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With this, if you're in `eu-central-1` you're screwed. – dannosaur Apr 07 '15 at 07:51
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`central` didn't exist when I initially wrote my answer. It's added now. – Daniel Kuppitz Apr 07 '15 at 08:24
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A script that breaks every time AWS adds a new region doesn't seem like a particularly strong solution, to me. – Ryan B. Lynch Jun 09 '15 at 17:19
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Instead of grep, `awk '{split($2,arr,"-"); print arr[1]"-"arr[2]}'` will keep just the first two components of the AZ name. – dskrvk Sep 14 '16 at 21:04
@dskrvk If you just keep the first two components, how do you distringuish between `eu-west-1`, `eu-west-2` and `eu-west-3` (Also `us-west-1` and `us-west-2`) @OP: just matching `'[a-z][a-z]-[a-z]*-[0-9][0-9]*'` seems safer (that is a basic regex, it can be made shorter with an extended RE). (The current regex will break on the `ca` region, the `af` regions and the `me` region) – Gert van den Berg Jul 06 '20 at 08:54

score 17 · Answer 7 · answered May 25 '16 at 13:46

17

Easiest I found so far

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

answered May 25 '16 at 13:46

Francesco Gualazzi

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This has the benefit of no non-default dependencies and it's only a single line. – Mark Stosberg Aug 29 '18 at 19:56

score 14 · Answer 8 · edited Mar 13 '13 at 00:43

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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}

edited Mar 13 '13 at 00:43

Beau Grantham

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answered Mar 13 '13 at 00:28

Ravi Kumar

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That's two lines – Christian Mar 27 '18 at 09:12
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But this is not working on us-west-1 region. Returns `curl: (6) Could not resolve host: instance-data; Name or service not known` error. – S.K. Venkat Apr 04 '18 at 10:08
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@S.K.Venkat That is likely related to your VPC's DNS settings... Using the IP for the metadata-api seems safer (half of the other answers does that) – Gert van den Berg Jul 06 '20 at 08:57

score 9 · Answer 9 · answered Sep 29 '18 at 20:02

If you have jq installed, you can also go about it (probably the most "graceful" method) this way:

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

This simply returns the raw value of "region" without any pretty-printing or other formatting. Reference: AWS Forum

score 7 · Answer 10 · answered Mar 03 '17 at 15:05

7

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

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

answered Mar 03 '17 at 15:05

mohrt

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SteveGoob · Answer 11 · 2020-10-27T17:15:25.513

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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

REGION="$(wget -q -O - 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/.

edited Oct 27 '20 at 17:15

answered Jun 30 '20 at 18:42

SteveGoob

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This worked for me on some instances, but on others I get 404 Not Found, even through the latest available release is 2020-10-27. – yurez Jan 19 '21 at 12:04
Huh, try just `http://169.254.169.254/latest/meta-data/placement`. Does `region` come back as one of the listed options? – SteveGoob Jan 19 '21 at 18:36
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It turned out that the problematic instances were running without restart since before `region` endpoint was added, which is why it was unavailable - as [documented](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/instancedata-data-categories.html). – yurez Jan 20 '21 at 11:58

score 6 · Answer 12 · answered Jul 17 '17 at 19:29

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Use JQ:

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

answered Jul 17 '17 at 19:29

Spanky

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score 4 · Answer 13 · answered Feb 20 '15 at 22:39

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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()

answered Feb 20 '15 at 22:39

Ken Weiner

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score 4 · Answer 14 · answered Apr 27 '15 at 23:10

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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

answered Apr 27 '15 at 23:10

Kelly Setzer

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Yep perfect, thanks. This result can easily be deserialized into a json object. – dynamiclynk Jun 16 '15 at 17:44
I'm getting a comma at the end. – Craig Jun 04 '17 at 04:32

score 4 · Answer 15 · edited Apr 13 '17 at 12:36

4

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.

edited Apr 13 '17 at 12:36

Community

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answered Sep 24 '15 at 18:05

Steve Jansen

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We've always been able to strip the last character in shell: `region=${region%?}` – David Jones Jan 21 '16 at 14:58

score 4 · Answer 16 · answered Sep 06 '17 at 14:03

4

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}

answered Sep 06 '17 at 14:03

Gil Zellner

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score 4 · Answer 17 · answered Feb 19 '18 at 21:32

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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

answered Feb 19 '18 at 21:32

dank

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score 3 · Answer 18 · edited Jan 23 '18 at 09:27

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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]$//'

edited Jan 23 '18 at 09:27

Michael Küller

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answered May 31 '17 at 00:16

Tyler Kellogg

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It should be `ec2metadata --availability-zone | sed 's/.$//'` (without dash) – Vladimir Kondratyev Nov 14 '19 at 22:08

score 3 · Answer 19 · answered Jun 06 '17 at 06:59

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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

answered Jun 06 '17 at 06:59

Alan

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score 3 · Answer 20 · answered Mar 09 '11 at 03:11

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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:]])}"}

answered Mar 09 '11 at 03:11

flaccid

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Note that this only works because __currently__ the availability zone is always the region name with a lower-case letter appended to it (e.g. region is "us-west-1", zone is "us-west-1a"). If Amazon ever breaks this pattern, then the logic above will no longer work. – Matt Solnit Apr 01 '11 at 16:19

score 3 · Answer 21 · answered May 25 '19 at 22:22

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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

answered May 25 '19 at 22:22

cwa

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score 1 · Answer 22 · answered Dec 01 '10 at 07:02

1

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,

answered Dec 01 '10 at 07:02

sheki

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This is incorrect. `ec2-metadata -z` only shows the availability zone, not the region. – Matt Solnit Apr 01 '11 at 16:21

score 1 · Answer 23 · answered Jun 20 '17 at 13:11

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

score 1 · Answer 24 · answered Apr 02 '19 at 23:41

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.

score 0 · Answer 25 · answered Oct 06 '19 at 02:50

0

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.)

answered Oct 06 '19 at 02:50

GViz

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This could depend on the virtual box type you've selected. I stick with Linux. – GViz Dec 09 '19 at 17:39

score 0 · Answer 26 · answered Apr 25 '20 at 16:51

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]')

score 0 · Answer 27 · answered Jun 10 '20 at 14:43

0

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'

answered Jun 10 '20 at 14:43

denken

1

score -1 · Answer 28 · answered Jul 28 '20 at 11:24

-1

You might get instance region using this curl request

$ curl http://169.254.169.254/latest/meta-data/placement/region
us-east-1

answered Jul 28 '20 at 11:24

Артем Косенко

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This is just a duplicate answer of https://stackoverflow.com/a/62664161/3966682 – d4nyll Aug 06 '20 at 03:57

Find region from within an EC2 instance

28 Answers28

Explanation of the REGEX:

If you want this into a variable do:

Linked

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