Let us turn our attention to the development environment which is what we extensively use on a daily basis at hudku.com. I strongly recommend one and all to make use of the Amazon’s AWS Free Usage Tier, fire up EC2 micro instance and give all the AWS services a spin.
You could be using the development environment scripts provided in this blog post to create an AWS Beanstalk environment, terminate the environment or deploy an application to an existing environment. We have made the development scripts to use EC2 micro instance by default and if you had noticed, the staging environment script, staging-create.sh also creates a micro instance. Once you have familiarized with the scripts you could change the settings such as EC2 instance type, minimum and maximum size of auto scaling group, etc. in the file beanstalk-configuration.txt to suit your requirements.
Please do not underestimate the power of EC2 micro instance. It comes with a memory of just around 608MB and that’s why having a swap file becomes more important. Please refer to our utility script mount-all-instance-storage.sh which creates a Linux system swap file. The micro instance does not come with any instance store and hence requires EBS (Elastic Block Store). Please note that the CPU time is available only in bursts and hence definitely not suited for CPU intensive jobs. But for downloading files from the Internet, accessing RDS instance or to serve web pages, the micro instance is no slouch. We tested it once by connecting the micro instance to the production load balancer as explained in the article “Zero Downtime with AWS Elastic Beanstalk” and in its third point, “Lending EC2 Instances to Production Load Balancer” and ran our website for about 10 minutes. During that period, the website had around 50 active users at any given instant and a single EC2 micro instance was able to serve that traffic. So for small websites with not so busy traffic, one could certainly consider using the EC2 micro instance.
Here is the directory structure we have been using and now it contains all the scripts.
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development-create.sh is used for creating the development environment. The main thing this script does is to change the values in the configuration file to suit the requirement of the development environment. Then this changed configuration file is passed as a parameter to staging-create.sh to create the development environment.
#!/bin/bash # Execute "export DEBUG=1" to debug this script. # Set value to 2 to debug this script and the scripts called within this script. # Set value to 3,4,5 and so on to increase the nesting level of the scripts to be debugged. [[ $DEBUG -gt 0 ]] && set -x; export DEBUG=$(($DEBUG - 1)) # # Creates a new Elastic Beanstalk Development environment # fileDevelopmentConfig=$ELASTICBEANSTALK_APP_TMP_DIR/beanstalk-development-configuration.txt # Alter the beanstalk configuration file and set the values required for development environment cat $ELASTICBEANSTALK_APP_DATA_DIR/beanstalk-configuration.txt | sed 's/"Value": "m1.large"/"Value": "t1.micro"/' > $fileDevelopmentConfig $ELASTICBEANSTALK_APP_SCRIPT_DIR/deployment/staging-create.sh $fileDevelopmentConfig
The script development-terminate.sh, to terminate the development environment, simply calls staging-terminate.sh passing it the Route53 DNS entry name of the development environment.
#!/bin/bash # Execute "export DEBUG=1" to debug this script. # Set value to 2 to debug this script and the scripts called within this script. # Set value to 3,4,5 and so on to increase the nesting level of the scripts to be debugged. [[ $DEBUG -gt 0 ]] && set -x; export DEBUG=$(($DEBUG - 1)) # # Terminates the development environment # $ELASTICBEANSTALK_APP_SCRIPT_DIR/deployment/staging-terminate.sh $ROUTE53_RR_DEVELOPMENT_NAME
development-deploy-new-app.sh is used to deploy a new version of the application on to the existing development environment.
#!/bin/bash # Execute "export DEBUG=1" to debug this script. # Set value to 2 to debug this script and the scripts called within this script. # Set value to 3,4,5 and so on to increase the nesting level of the scripts to be debugged. [[ $DEBUG -gt 0 ]] && set -x; export DEBUG=$(($DEBUG - 1)) # # Deploys a new version of the application to the Elastic Beanstalk Development environment # $ELASTICBEANSTALK_APP_SCRIPT_DIR/deployment/staging-deploy-new-app.sh $ROUTE53_RR_DEVELOPMENT_NAME
Now you have the source code of all the scripts we use to customize the AWS Elastic Beanstalk environment. The idea behind publishing the blog posts at such a rapid pace was to make all these scripts available as early as possible, so that anybody interested could get going quickly with AWS Elastic Beanstalk. Definitely next time, I shall think twice before I commit myself to write a serial of blog posts.
Next post is going to be the final part of “Customizing AWS Elastic Beanstalk” and in that post I shall provide a download link to a zip file containing all the scripts and also any instructions that may be required to use it. But before providing the zip file, I want to test it completely and while doing that I intend to record all the steps carefully. So I shall take my time for the testing and sometime during next week you can expect the next post.