Bash function for SSH into EC2 by Name Tag

ssh-to-ec2-by-tag-name

<< //// 
This function will ssh into a EC2 based on Name tags. You can ssh in via public or private IP This function requires awscli to work 
There are several optional environment variables:
   AWS_PROFILE = Control which profile is active with this variable, if this is unset the function will use AWS_DEFAULT_PROFILE instead
   SSH_EC2_KEY_FILE = path to the key file for the user 
   SSH_EC2_USER = name of the user that logs in, if this variable is unset the value is ec2-user

To use this function do the following commands
(from command line)

1) mkdir -p ~/gist
2) git -C ~/gist clone git@gist.github.com:30060471804df63e32c1f0a23251d2e3.git 

Then copy the following (if to fi) into your ~/.bashrc

if [ -f $HOME/gist/30060471804df63e32c1f0a23251d2e3/ssh-to-ec2-by-tag-name ]; then
   . $HOME/gist/30060471804df63e32c1f0a23251d2e3/ssh-to-ec2-by-tag-name
fi

Then either 'source ~/.bashrc' or close the terminal and open a new one
////

SSH_EC2_PARAMS='-o ServerAliveInterval=30 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -o ForwardAgent=yes'

function hostname_from_instance() {
    if [ ! -z "$AWS_PROFILE" ]; then
       AWS_DEFAULT_PROFILE=$AWS_PROFILE;
    fi
    echo $(aws ec2 describe-instances --filters "{\"Name\":\"tag:Name\", \"Values\":[\"$1\"]}" "{\"Name\":\"instance-state-name\", \"Values\":[\"running\", \"pending\"]}" --query='Reservations[0].Instances[0].PublicDnsName' | tr -d '"');
}

function ip_from_instance_priv() {
    if [ ! -z "$AWS_PROFILE" ]; then
      AWS_DEFAULT_PROFILE=$AWS_PROFILE;
    fi
    echo $(aws ec2 describe-instances --filters "{\"Name\":\"tag:Name\", \"Values\":[\"$1\"]}" "{\"Name\":\"instance-state-name\", \"Values\":[\"running\", \"pending\"]}" --query='Reservations[0].Instances[0].PrivateIpAddress' | tr -d '"');
}

function ip_from_instance_pub() {
    if [ ! -z "$AWS_PROFILE" ]; then
      AWS_DEFAULT_PROFILE=$AWS_PROFILE;
    fi
    echo $(aws ec2 describe-instances --filters "{\"Name\":\"tag:Name\", \"Values\":[\"$1\"]}" "{\"Name\":\"instance-state-name\", \"Values\":[\"running\", \"pending\"]}" --query='Reservations[0].Instances[0].PublicIpAddress' | tr -d '"');
}

function ssh-ec2-priv() {
    if [  -z "$SSH_EC2_USER" ]; then 
       SSH_EC2_USER='ec2-user';
    fi
    if [  -z "$SSH_EC2_KEY_FILE" ]; then 
       ssh $SSH_EC2_PARAMS $SSH_EC2_USER@$(ip_from_instance_priv "$1");
    else
       ssh $SSH_EC2_PARAMS -i $SSH_EC2_KEY_FILE $SSH_EC2_USER@$(ip_from_instance_priv "$1");
    fi
}

function ssh-ec2-pub() {
    if [  -z "$SSH_EC2_USER" ]; then 
       SSH_EC2_USER='ec2-user';
    fi
    if [  -z "$SSH_EC2_KEY_FILE" ]; then
       ssh $SSH_EC2_PARAMS $SSH_EC2_USER@$(ip_from_instance_pub "$1");
    else
       ssh $SSH_EC2_PARAMS -i $SSH_EC2_KEY_FILE $SSH_EC2_USER@$(ip_from_instance_pub "$1");
    fi
}

function sftp-ec2-priv() {
    if [  -z "$SSH_EC2_USER" ]; then
       SSH_EC2_USER='ec2-user';
    fi
    if [  -z "$SSH_EC2_KEY_FILE" ]; then
       sftp $SSH_EC2_PARAMS $SSH_EC2_USER@$(ip_from_instance_priv "$1");
    else
       sftp $SSH_EC2_PARAMS -i $SSH_EC2_KEY_FILE $SSH_EC2_USER@$(ip_from_instance_priv "$1");
    fi
}

function sftp-ec2-pub() {
    if [  -z "$SSH_EC2_USER" ]; then
       SSH_EC2_USER='ec2-user';
    fi
    if [  -z "$SSH_EC2_KEY_FILE" ]; then
       sftp $SSH_EC2_PARAMS $SSH_EC2_USER@$(ip_from_instance_pub "$1");
    else
       sftp $SSH_EC2_PARAMS -i $SSH_EC2_KEY_FILE $SSH_EC2_USER@$(ip_from_instance_pub "$1");
    fi
}