Problem connecting to EC2 instance via GIT BASH - amazon-web-services

Question

I have a problem connecting to my aws ec2 instance, i can easily connect to my jumpbox instance and then when i try to ssh to my private ec2 it does not let me. I think it has something to do with my key pair, i only have one on my aws account so i don't know why it does not let me connect to it so i can install something. I didn't have this problem before but now i have been stuck on it for days. I have attached the error and says ECDSA key fingerprint twice when i ssh to my private instance so i'm guessing that has something to do with the problem.
If someone knows please advise.
enter code hereJUMPBOXSecurityGroup:
Type: AWS::EC2::SecurityGroup
Properties:
GroupDescription: 'JUMPBOX Security Group'
GroupName: JUMPBOXSG
SecurityGroupIngress:
- CidrIp: 0.0.0.0/0
Description: 'SSH from my IP address'
FromPort: 22
ToPort: 22
IpProtocol: tcp
VpcId: !Ref Myvpc
Tags:
- Key: Name
Value: JUMPBOXSecurityGroup
enter code hereJUMPBOXEC2Instance:
Type: AWS::EC2::Instance
Properties:
ImageId: ami-08e4e35cccc6189f4
InstanceType: t2.micro
NetworkInterfaces:
- AssociatePublicIpAddress: "true"
DeviceIndex: "0" ### dodeluva public ip adressa na prviot interface
SubnetId: !Ref MyPublicSubnet
GroupSet:
- !Ref JUMPBOXSecurityGroup
KeyName: Key
Tags:
- Key: Name
Value: JUMPBOXEC2Instance
Here is my jumpbox instance with security group
enter code hereMyPublicEC2InstanceSG:
Type: AWS::EC2::SecurityGroup
Properties:
GroupDescription: 'Public EC2 Security Group'
SecurityGroupIngress:
- CidrIp: 0.0.0.0/0
Description: 'http from everuwhere'
FromPort: 80
ToPort: 80
IpProtocol: tcp
- SourceSecurityGroupId: !Ref JUMPBOXSecurityGroup
Description: 'ssh from Jumpbox'
FromPort: 22
ToPort: 22
IpProtocol: tcp
VpcId: !Ref Myvpc
Tags:
- Key: Name
Value: MyPublicEC2InstanceSG
MyPublicEC2Instance:
Type: AWS::EC2::Instance
Properties:
ImageId: ami-0b5eea76982371e91
InstanceType: t2.micro
NetworkInterfaces:
- AssociatePublicIpAddress: "true"
DeviceIndex: "0" ### dodeluva public ip adressa na prviot network interface
SubnetId: !Ref MyPublicSubnet
GroupSet:
- !Ref MyPublicEC2InstanceSG
KeyName: Key
Tags:
- Key: Name
Value: MyPublicEC2Instance
Here is my public ec2 instance with security group

Answer 1

Since you're seeing an actual "permission denied" error, it's not likely a security group issue. Those tend to cause the connection to hang and/or time out.
Seems like the wrong ssh key is being used. From your "jumpbox" (i.e. not your local machine), add "-vvv" to the ssh command (ex. ssh -vvv es2-user#10.1.5.157). In the output, you'll see which key or config file is being used. If an ssh config file is being used on the jumpbox instance, be sure it's pointing to the correct key, and that the key exists on the jumpbox. If the wrong key is being used, simply supply the correct one using the -i option of the ssh command, or update the config file to point to the correct key location.
My guess is that the correct key doesn't exist on your jumpbox. SSH does not automatically forward your key between instances. So a quick fix would be to copy the key to the jumpbox. But the preferred way would be to enable agent forwarding from your local machine. (see: https://docs.github.com/en/developers/overview/using-ssh-agent-forwarding)
Actually, ideally you would connect using SSM instead! (see: https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/session-manager.html) This has its own list of headaches, but once you get it running it lets you connect without a jumpbox and without keypairs. You also don't need to leave port 22 open on any instances.