Incorrect Content-Type response header

[ash211]

Describe the bug The real http://169.254.169.254/latest/meta-data/iam/security-credentials/instant-launch endpoint returns an HTTP response with header Content-Type: text/plain but this mock docker container returns with header Content-Type: application/json. This makes the docker container non-representative of actual AWS EC2 metadata endpoint behavior, and causes problems with some libraries that expect JSON objects to be returned with Content-Type: application/json.

Steps to reproduce On an EC2 instance:

$ export TOKEN=`curl -XPUT -H "X-aws-ec2-metadata-token-ttl-seconds: 21600" http://169.254.169.254/latest/api/token`
$ export ROLE_NAME=`curl -H "X-aws-ec2-metadata-token: $TOKEN" http://169.254.169.254/latest/meta-data/iam/security-credentials/`
$ curl -s -vvv -H "X-aws-ec2-metadata-token: $TOKEN" http://169.254.169.254/latest/meta-data/iam/security-credentials/$ROLE_NAME 2>&1 | grep 'Content-Type'
< Content-Type: text/plain
$

Against this docker container running at localhost:1339:

$ export TOKEN=`curl -XPUT -H "X-aws-ec2-metadata-token-ttl-seconds: 21600" http://localhost:1339/latest/api/token`
$ export ROLE_NAME=`curl -H "X-aws-ec2-metadata-token: $TOKEN" http://localhost:1339/latest/meta-data/iam/security-credentials/`
$  curl -s -vvv -H "X-aws-ec2-metadata-token: $TOKEN" http://localhost:1339/latest/meta-data/iam/security-credentials/$ROLE_NAME 2>&1 | grep 'Content-Type'
< Content-Type: application/json
$

Expected outcome The second sequence of curl requests above should result in Content-Type: text/plain instead of Content-Type: application/json

Environment

• AEMM Version: docker container aws-ec2/amazon-ec2-metadata-mock:v1.11.2
• OS/Arch: Mac OS X
• Installation method: docker run

flags: -p 1339 -I -c /aemm-config-overrides.json

And that file's contents:

{
  "metadata": {
    "paths": {
      "placement-availability-zone": "/latest/meta-data/placement/availability-zone"
    },
    "values": {
      "placement-availability-zone": "us-west-1c"
    }
  }
}

[github-actions[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. If you want this issue to never become stale, please ask a maintainer to apply the "stalebot-ignore" label.

[ash211]

Not stale

[github-actions[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. If you want this issue to never become stale, please ask a maintainer to apply the "stalebot-ignore" label.

[github-actions[bot]]

This issue was closed because it has become stale with no activity.