Query EC2 tags from within instance

Question

Amazon recently added the wonderful feature of tagging EC2 instances with key-value pairs to make management of large numbers of VMs a bit easier   Is there some way to query these tags in the same way as some of the other user-set data  For example     curl http   169 254 169 254 latest meta-data placement availability-zone us-east-1d   Is there some similar way to query the tags

User · Answer

If you are not in the default availability zone the results from overthink would return empty.

ec2-describe-tags \
   --region \
     $(curl -s http://169.254.169.254/latest/meta-data/placement/availability-zone  | sed -e "s/.$//") \
   --filter \
     resource-id=$(curl --silent http://169.254.169.254/latest/meta-data/instance-id)

If you want to add a filter to get a specific tag (elasticbeanstalk:environment-name in my case) then you can do this.

ec2-describe-tags \
   --region \
     $(curl -s http://169.254.169.254/latest/meta-data/placement/availability-zone  | sed -e "s/.$//") \
   --filter \
     resource-id=$(curl --silent http://169.254.169.254/latest/meta-data/instance-id) \
   --filter \
     key=elasticbeanstalk:environment-name | cut -f5

And to get only the value for the tag that I filtered on, we pipe to cut and get the fifth field.

ec2-describe-tags \
  --region \
    $(curl -s http://169.254.169.254/latest/meta-data/placement/availability-zone  | sed -e "s/.$//") \
  --filter \
    resource-id=$(curl --silent http://169.254.169.254/latest/meta-data/instance-id) \
  --filter \
    key=elasticbeanstalk:environment-name | cut -f5

User · Answer

The following bash script returns the Name of your current ec2 instance  the value of the  Name  tag   Modify TAG NAME to your specific case   TAG NAME  Name  INSTANCE ID   wget -qO- http   instance-data latest meta-data instance-id   REGION   wget -qO- http   instance-data latest meta-data placement availability-zone   sed -e  s    0-9  0-9     a-z       1     TAG VALUE   aws ec2 describe-tags --filters  Name resource-id Values  INSTANCE ID   Name key Values  TAG NAME  --region  REGION --output text   cut -f5     To install the aws cli  sudo apt-get install python-pip -y sudo pip install awscli   In case you use IAM instead of explicit credentials  use these IAM permissions        Version    2012-10-17      Statement                      Effect    Allow          Action      ec2 DescribeTags           Resource

User · Answer

I have pieced together the following that is hopefully simpler and cleaner than some of the existing answers and uses only the AWS CLI and no additional tools   This code example shows how to get the value of tag  myTag  for the current EC2 instance   Using describe-tags   export AWS DEFAULT REGION us-east-1 instance id   curl -s http   169 254 169 254 latest meta-data instance-id  aws ec2 describe-tags     --filters  Name resource-id Values  instance id   Name key Values myTag      --query  Tags   Value  --output text   Or  alternatively  using describe-instances   aws ec2 describe-instances --instance-id  instance id     --query  Reservations   Instances   Tags  Key   myTag   Value  --output text

User · Answer

Once you ve got ec2-metadata and ec2-describe-tags installed  as mentioned in Ranieri s answer above   here s an example shell command to get the  name  of the current instance  assuming you have a  Name Foo  tag on it   Assumes EC2 PRIVATE KEY and EC2 CERT environment variables are set   ec2-describe-tags     --filter  resource-type instance      --filter  resource-id   ec2-metadata -i   cut -d     -f2       --filter  key Name    cut -f5   This returns Foo

User · Answer

For those crazy enough to use Fish shell on EC2  here s a handy snippet for your  home ec2-user  config fish config fish  The hostdata command now will list all your tags as well as the public IP and hostname  set -x INSTANCE ID  wget -qO- http   instance-data latest meta-data instance-id  set -x REGION  wget -qO- http   instance-data latest meta-data placement availability-zone   sed  s         function hostdata     aws ec2 describe-tags --region  REGION --filter  quot Name resource-id Values  INSTANCE ID quot  --output text   sed -r  s TAGS t     t   t   t      1  quot  2 quot        ec2-metadata   grep public-hostname     ec2-metadata   grep public-ipv4 end

User · Answer

You can alternatively use the describe-instances cli call rather than describe-tags   This example shows how to get the value of tag  my-tag-name  for the instance   aws ec2 describe-instances     --instance-id   curl -s http   169 254 169 254 latest meta-data instance-id      --query  Reservations    Instances    Tags  Key   my-tag-name   Value      --region ap-southeast-2 --output text   Change the region to suit your local circumstances  This may be useful where your instance has the describe-instances privilege but not describe-tags in the instance profile policy

User · Answer

Using the AWS  user data  and  meta data  APIs its possible to write a script which wraps puppet to start a puppet run with a custom cert name    First start an aws instance with custom user data   role webserver      bin bash    Find the name from the user data passed in on instance creation USER   curl -s  http   169 254 169 254 latest user-data   IFS     read -ra UDATA  lt  lt  lt    USER     Find the instance ID from the meta data api ID   curl -s  http   169 254 169 254 latest meta-data instance-id   CERTNAME   UDATA 1    ID aws  echo  Running Puppet for certname     CERTNAME puppet agent -t --certname  CERTNAME    This calls puppet with a certname like  webserver i-hfg453 aws  you can then create a node manifest called  webserver  and puppets  fuzzy node matching  will mean it is used to provision all webservers    This example assumes you build on a base image with puppet installed etc    Benefits   1  You don t have to pass round your credentials  2  You can be as granular as you like with the role configs

User · Answer

For Python   from boto import utils  ec2 from os import environ    import keys from os env or use default  not secure  aws access key id   environ get  AWS ACCESS KEY ID   failobj  XXXXXXXXXXX   aws secret access key   environ get  AWS SECRET ACCESS KEY   failobj  XXXXXXXXXXXXXXXXXXXXX     load metadata   if       we are on localhost   http   docs aws amazon com AWSEC2 latest UserGuide AESDG-chapter-instancedata html instance metadata   utils get instance metadata timeout 0 5  num retries 1  region   instance metadata  placement    availability-zone    -1  instance id   instance metadata  instance-id    conn   ec2 connect to region region  aws access key id aws access key id  aws secret access key aws secret access key    get tag status for our  instance id using filters   http   docs aws amazon com AWSEC2 latest CommandLineReference ApiReference-cmd-DescribeTags html tags   conn get all tags filters   resource-id   instance id   key    status    if tags      instance status   tags 0  value else      instance status   None     logging error  no status tag for   region     instance id

User · Answer

A variation on some of the answers above but this is how I got the value of a specific tag from the user-data script on an instance  REGION   curl http   instance-data latest meta-data placement availability-zone   sed  s         INSTANCE ID   curl -s http   instance-data latest meta-data instance-id   TAG VALUE   aws ec2 describe-tags --region  REGION --filters  Name resource-id Values  INSTANCE ID   Name key Values   lt TAG NAME HERE gt      jq -r   Tags   Value

User · Answer

You can use a combination of the AWS metadata tool  to retrieve your instance ID  and the new Tag API to retrieve the tags for the current instance

User · Answer

Download and run a standalone executable to do that   Sometimes one cannot install awscli that depends on python  docker might be out of the picture too   Here is my implementation in golang  https   github com hmalphettes go-ec2-describe-tags

User · Answer

Jq   ec2metadata makes it a little nicer  I m using cf and have access to the region  Otherwise you can grab it in bash  aws ec2 describe-tags --region  REGION   --filters  quot Name resource-id Values  ec2metadata --instance-id  quot    jq --raw-output     Tags     select  Key   quot TAG NAME quot      Value   No jq  aws ec2 describe-tags --region us-west-2   --filters  quot Name resource-id Values  ec2-metadata --instance-id   cut -d  quot   quot  -f 2  quot    --query  Tags  Key   Name   Value    --output text

User · Answer

You can add this script to your cloud-init user data to download EC2 tags to a local file      bin sh INSTANCE ID  wget -qO- http   instance-data latest meta-data instance-id  REGION  wget -qO- http   instance-data latest meta-data placement availability-zone   sed  s        aws ec2 describe-tags --region  REGION --filter  Name resource-id Values  INSTANCE ID  --output text   sed -r  s TAGS t     t   t   t      1   2     gt   etc ec2-tags   You need the AWS CLI tools installed on your system  you can either install them with a packages section in a cloud-config file before the script  use an AMI that already includes them  or add an apt or yum command at the beginning of the script   In order to access EC2 tags you need a policy like this one in your instance s IAM role        Version    2012-10-17      Statement                  Sid    Stmt1409309287000          Effect    Allow          Action              ec2 DescribeTags                  Resource                                       The instance s EC2 tags will available in  etc ec2-tags in this format   FOO  Bar  Name  EC2 tags with cloud-init    You can include the file as-is in a shell script using    etc ec2-tags  for example      bin sh    etc ec2-tags echo  Name   The tags are downloaded during instance initialization  so they will not reflect subsequent changes     The script and IAM policy are based on itaifrenkel s answer

User · Answer

Install AWS CLI   curl  https   s3 amazonaws com aws-cli awscli-bundle zip  -o  awscli-bundle zip  sudo apt-get install unzip unzip awscli-bundle zip sudo   awscli-bundle install -i  usr local aws -b  usr local bin aws   Get the tags for the current instance   aws ec2 describe-tags --filters  Name resource-id Values  ec2metadata --instance-id     Outputs          Tags                            ResourceType    instance                 ResourceId    i-6a7e559d                 Value    Webserver                 Key    Name                      Use a bit of perl to extract the tags   aws ec2 describe-tags --filters    Name resource-id Values  ec2metadata --instance-id       perl -ne  print   1 n  if    Value                  Returns   Webserver

[amazon-web-services] Query EC2 tags from within instance

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