`Temporary failure in name resolution` on freshly created AWS EC2 instance

Question

I am new to AWS.

I had another issue with an instance, so I decided that I delete it and redo the steps to create a new one:

1. Define a key pair;
2. Create a stack from a template;
3. Access the instance with ssh;
4. Install apps I want to use.

Here is the template I use

Resources:
  AppNode:
    Type: AWS::EC2::Instance
    Properties:
      InstanceType: t2.nano
      ImageId: ami-06a719e5f8e22c33b
      KeyName: influxdb_example_3
      SecurityGroups:
        - !Ref AppNodeSG
      UserData: !Base64 |
        #!/bin/bash
        apt-get update -qq
        apt-get install -y apt-transport-https ca-certificates
        apt-key adv apt-key adv --keyserver hkp://p80.pool.sks-keyservers.net:80 --recv-keys 58118E89F3A912897C070ADBF76221572C52609D
        apt-get update -qq apt-get purge lxc-docker || true
        curl -fsSL https://download.docker.com/linux/ubuntu/gpg | apt-key add -
        add-apt-repository "deb [arch=amd65] https://download.docker.com/linux/ubuntu bionic stable"
        apt-get -y install linux-image-extra-$(uname -r) linux-image-extra-virtual
        apt-get -y install docker-ce
        usermod -aG docker unbuntu
        docker image pull quay.io/influxdb/influxdb:v2.0.2
        docker container run -p 80:9999 quay.io/influxdb/influxdb:v2.0.2
  AppNodeSG:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupDescription: for the app nodes that allow ssh
      SecurityGroupIngress:
        - IpProtocol: tcp
          FromPort: "80"
          ToPort: "80"
          CidrIp: 0.0.0.0/0
        - IpProtocol: tcp
          FromPort: "22"
          ToPort: "22"
          CidrIp: 0.0.0.0/0

This is how I create the stack

aws cloudformation create-stack \
  --stack-name influxdb-trial-stack-2 \
  --region eu-central-1 \
  --template-body file://$PWD/stack.yaml

And this is how I access it:

ssh -i influxdb_example_3.pem \
    ubuntu@ec2-18-159-XXX-XX.eu-central-1.compute.amazonaws.com

I manage to create the stack/instance and access it. Since the second attempt, however, whenever I try to do anything there with sudo it reacts very slowly and I got the unable to resolve host ip-172-31-xx-xxx: Temporary failure in name resolution message. I have gone through the steps three times already, but it always comes down to this.

The nearest thing I found was here: https://forums.aws.amazon.com/thread.jspa?threadID=132414.

Based on that, I inserted the private ip/dns into etc/hosts, but it did not help (though it talks about 'network restart'. Is it the same as instance reboot?)

I understand that there are different manual ways to fix this issue, but as in the first time it did work for me, and as I would assume that the stack creation process is automatic, I suspect that there is some config/cache/??? issue I am not aware of.

Any suggestions are appreciated.

Answer 1

It turned out that using a different AMI solved the issue.

My second and further setups used a different AMI from the first just I forgot about this and did not even think that the AMI could be the problem.