Stopping preproduction, staging environment EC2 instances could be described sometimes as a good practice. In the next few lines, I’ll show you how you can easily stop all running EC2 instances from the CLI in a single command.
Prerequisites
- AWS CLI
Stop all running EC2 instances
Step 1. Open Terminal and check if AWS CLI is installed.
aws --version
Output:
aws-cli/2.1.39 Python/3.9.4 Darwin/20.5.0 source/x86_64 prompt/off
Step 2. Check if AWS CLI is configured.
aws configure list
Output:
Name Value Type Location
---- ----- ---- --------
profile <not set> None None
access_key ****************ABCD config_file ~/.aws/config
secret_key ****************ABCD config_file ~/.aws/config
region us-west-2 env AWS_DEFAULT_REGION
Step 3. Get a list of all running EC2 instances.
aws ec2 describe-instances --filters Name=instance-state-name,Values=running --query 'Reservations[].Instances[].InstanceId'
Depending on the number of instances, you will get a JSON response including the instances IDs.
Output:
[
"i-<some-instance-id>",
"i-<some-other-instance-id>"
]
Step 4. Replace new lines with spaces using the Linux command line utility tr.
aws ec2 describe-instances --filters Name=instance-state-name,Values=running --query 'Reservations[].Instances[].InstanceId' --output text | tr '\n' ' '
Output:
i-<some-instance-id> i-<some-other-instance-id> %
Step 5. It’s always a good practice to execute a dry run.
aws ec2 stop-instances --dry-run --instance-ids $(aws ec2 describe-instances --filters Name=instance-state-name,Values=running --query 'Reservations[].Instances[].InstanceId' --output text | tr '\n' ' ')
Output:
An error occurred (DryRunOperation) when calling the StopInstances operation: Request would have succeeded, but DryRun flag is set.
Step 6. Remove the --dry-run flag and stop all running EC2 instances.
aws ec2 stop-instances --instance-ids $(aws ec2 describe-instances --filters Name=instance-state-name,Values=running --query 'Reservations[].Instances[].InstanceId' --output text | tr '\n' ' ')
Conclusion
The next key step is automation. You could use a cronjob on your local machine, HA server or even better, deploy a lambda function that will trigger the stop command. On the other hand, don’t forget to create a command that will start all stopped EC2 instances every morning. This will be covered in the next upcoming posts.
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