I prefer creating the base AMI using packer; RDS snapshot using a Jenkins job which get triggered whenever there is a change in the database schema in the SCM. In case of installers, binaries, etc. it would be best to store them in a single S3 bucket. In all the above mentioned scenarios I prefer to share those resources to a 3rd party AWS account and remove the share when not needed. Automating this would be easy to handle add/remove permissions, hence I decided to hold the sharing details in a JSON file in the SCM. Changes to that file will trigger a Jenkins job which will invoke a Lambda function which in turn will share the resources based on the values in the JSON file. Read more

AWS Lambda supports only Java, JavaScript & Python at the time of writing this post. I was wondering whether I can exploit the Lambda to execute chef’s knife commands on it since Lambda runs on a Linux container. Using simple python function I have identified that the code of the Lambda function gets copied to /var/task and executed from there. I decided to custom build ruby as embedded platform similar to how chef-client or chefdk are distributed. My requirement is to execute knife commands and its uses embedded ruby version 2.1.0, hence I downloaded the source archive that specific version. Read more

Most of the AWS resources are billed on per-hour basis which provides us an opportunity to save cost based on the usage pattern. Especially in case of Dev/Test environment, we need them only during the working days and working hours. By using AWS Lambda function (python) in combination with EC2 instance tags, scheduled start or stop can be achieved with few lines of code. Advantages of using AWS Lambda: For 128MB memory we get 3,200,000 seconds free tier usage per month in AWS Lambda which will be more than enough for this function. IAM role will be associated with the Lambda function which will be used to perform the required task and no separate keys need to be configured. I used a tag with name as schedule & JSON string for tag value using which I could define the day and time when it needs to be started or stopped. Read more