Connect EC2 Instance using Git Bash via SSH command

SaurabhG
4 min readFeb 10, 2023

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Hi Folks,

In my previous attempt to automatically start/stop Ec2 Instance I have written a shell script which takes Instance Id as input and perform actions(to stop or start the instance) based on instance state.

In extension to that, today I have written another script which performs similar action along with that it automatically connects the Ec2 instance.

To execute this script users need to have EC2 instance launch Key (.pem) file in local folder and Git Bash should be installed on local machine.

The mentioned automation performs following task.

  1. Stop the running instance based on given instance Id
  2. Connect the existing running instance for given instance Id
  3. Start the stopped instance for given instance Id, verify the 2/2 check on instance and connect the instance.

Script URL : https://github.com/SaurabhG-20/AWS-Instance-start-stop-atuoamtion/blob/main/get_instance_connection_command.sh

Here Are the following sample output achieved while executing the script.

  1. Stopping the running instance
Stopping the running instance

2. Connect the existing running instance

Connecting existing running instance

3. Start the stopped instance, verify 2/2 check on instance & connect the instance

This automation has helped to avoid login into AWS console for start/stop action on the EC2 instance. & on need basis I am able to control use consumption of the EC2 instance.

Please refer the mentioned automation for Ubuntu based EC2 Instances. Feel free to form my git hub repo for accessing the script or modifying the script

Script Code

#!/bin/sh
clear
echo -e "\n=======================================================\n"
echo "Script for Automated start/stop action for AWS EC2 Machine"
echo -e "\n=======================================================\n"

read -p "> Enter Instance Id ? " instance_id

while true; do
if [[ -z "$instance_id" ]] # If both instance name ond instance id is empty
then
echo -e "\nInstance Id must be provided."
read -p "Enter Instance Id ? " instance_id
else
break
fi
done

echo -e "\n> Fetching EC2 Instance State for Instance ID : $instance_id"
instance_state=$(aws ec2 describe-instance-status --instance-id $instance_id --query 'InstanceStatuses[*].InstanceState.Name' --output text)
if [[ -z "$instance_state" ]]
then
echo -e "\n> Instance is in stopped state. Starting the instance"
# on first execution start-instances command returns "pending" state.
# we can run small while loop to check if instance started successfully or not
instance_start_invoke=$(aws ec2 start-instances --instance-ids $instance_id --query 'StartingInstances[*].CurrentState.Name' --output text)
echo -e "\n> Start instance command execution result : $instance_start_invoke"
if [ "$instance_start_invoke" = "pending" ]
then
fetch_instance_start=$instance_start_invoke
while [ "$fetch_instance_start" = "pending" ]
do
fetch_instance_start=$(aws ec2 start-instances --instance-ids $instance_id --query 'StartingInstances[*].CurrentState.Name' --output text)
echo " --> Instance state : $fetch_instance_start"
sleep 5
done
echo " --> -------------------------------------------"
echo " --> Instance state : $fetch_instance_start"
echo -e "\n> Chekcing Instance Health status"
fetch_instance_health="initializing"
while [ "$fetch_instance_health" = "initializing" ]
do
fetch_instance_health=$(aws ec2 describe-instance-status --instance-id $instance_id --query 'InstanceStatuses[*].InstanceStatus.Status' --output text)
echo " --> Instance health check : $fetch_instance_health"
sleep 10
done
echo " --> -------------------------------------------"
echo " --> Instance health : $fetch_instance_health"
echo -e "\n> Getting instance connection command"
instance_data=$(aws ec2 describe-instances --filters Name=instance-id,Values=$instance_id --query 'Reservations[*].Instances[*].{KeyName:KeyName,PublicDnsname:PublicDnsName}' --output text)
if [[ ! -z "$instance_data" ]]
then
instance_key=$(echo $instance_data | head -n1 | awk '{print $1;}')".pem"
instance_dns="ubuntu@"$(echo $instance_data | head -n1 | awk '{print $2;}')
if [[ ! -z "$instance_key" ]] && [[ ! -z "$instance_dns" ]]
then
command_text="ssh -i "'"'$instance_key'"'" $instance_dns"
echo -e "\n> EC2 VM SSH Connection command is:\n\n> $command_text"
echo -e "\n> Connecting EC2 VM $instance_id"
echo -e "\n--------------------------------------\n"
eval $command_text # To execute command with in shell script
fi
fi
fi
elif [[ "$instance_state" = "running" ]]
then
echo -e "\n> Instance is in running state, Do you want to stop the instance?\n"
read -p "> Enter Option Y for yes / N for No ? " option
# keeping while loop for oprtion selection
while true; do
if [[ -z "$option" ]] # If both instance name ond instance id is empty
then
echo -e "\n> Option must be provided!\n"
read -p "> Enter Option Y for yes / N for No ? " option
else
break
fi
done
# swicth case to handler if instance to be stop or get ssh connection command
case $option in
"Y")
echo -e "\n> Selected Opion is Yes. Stopping the instance"
instnace_stop_invoke=$(aws ec2 stop-instances --instance-ids $instance_id --query 'StoppingInstances[*].CurrentState.Name' --output text)
echo -e "\n> Instance state : $instnace_stop_invoke"
echo -e "\n> Instance will be stopped after sometime.\n"
read -s -n 1 -p "Press any key to continue . . ."
;;
"N")
echo -e "\n> Selected Opion is No. Keeping the instance ON"
echo -e "\n> Getting instance connection command"
instance_data=$(aws ec2 describe-instances --filters Name=instance-id,Values=$instance_id --query 'Reservations[*].Instances[*].{KeyName:KeyName,PublicDnsname:PublicDnsName}' --output text)
if [[ ! -z "$instance_data" ]]
then
instance_key=$(echo $instance_data | head -n1 | awk '{print $1;}')".pem"
instance_dns="ubuntu@"$(echo $instance_data | head -n1 | awk '{print $2;}')
if [[ ! -z "$instance_key" ]] && [[ ! -z "$instance_dns" ]]
then
command_text="ssh -i "'"'$instance_key'"'" $instance_dns"
echo -e "\n> EC2 VM SSH Connection command is:\n\n> $command_text"
echo -e "\n> Connecting EC2 VM $instance_id"
echo -e "\n--------------------------------------\n"
eval $command_text # To execute command with in shell script
fi
fi
;;
*)
echo "Not a valid argument"
echo
;;
esac

fi

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SaurabhG

I am an enthusiastic learner. Always want to challenge my last learning & keep hunting for new learning. about.me/saurabh.gangrade