How do I change the configured RDS endpoint of an AWS Elastic Beanstalk environment?
E.g. after the RDS database was deleted or should be replaced with a new RDS database.
Update
The topic remains complex and the AWS Elastic Beanstalk (EB) documentation could still do a better job to clarify available options. The question has been about how to change an RDS endpoint, which seems to be read in two different ways:
One could interpret it about how to attach an existing externally managed RDS endpoint to an existing (not new!) EB environment - this is indeed not possible, rather one would need to resort to handling this scenario from within the app itself as e.g. outlined in section Using an Existing Amazon RDS DB Instance with Python within Using Amazon RDS with Python.
Rather, the OP asked about how to do that after the RDS database was deleted or should be replaced with a new RDS database, i.e. the RDS endpoint change is implied in the process of creating a new RDS database for an existing EB environment that already had one - this is indeed possible by means of the DBSnapshotIdentifier Option Value, which denotes The identifier for the DB snapshot to restore from. Once again the EB docs aren't exactly conclusive what this means, however, EB is using AWS CloudFormation under the hood, and the resp. entry for AWS::RDS::DBInstance - DBSnapshotIdentifier provides more details:
By specifying this property, you can create a DB instance from the
specified DB snapshot. If the DBSnapshotIdentifier property is an
empty string or the AWS::RDS::DBInstance declaration has no
DBSnapshotIdentifier property, the database is created as a new
database. If the property contains a value (other than empty string),
AWS CloudFormation creates a database from the specified snapshot. If
a snapshot with the specified name does not exist, the database
creation fails and the stack rolls back.
In other words, the typical result of updating any of the General Option Values from namespace aws:rds:dbinstance for an existing EB environment is the creation of a respectively adjusted RDS instance managed by EB, and thus a new RDS endpoint.
A specific sub scenario is the use of DBSnapshotIdentifier, which yields a new RDS instance managed by EB based on the referenced snapshot and can therefore be used to migrate (rather than attach) an existing externally managed RDS instance, albeit with considerable downtime based on the snapshot size.
Initial Answer
While unfortunately not specifically addressed within Configuring Databases with AWS Elastic Beanstalk, the AWS Elastic Beanstalk settings for an optional Amazon RDS database are handled via Option Values, see namespace aws:rds:dbinstance within General Options.
While the AWS Management Console hides many of those option values behind its UI, you can specify them explicitly when using the API via other means, both when creating an environment as well as when updating one (which is how you would change any settings of an RDS database instance) - see e.g. parameter --option-settings for update-environment from the the AWS Command Line Interface:
If specified, AWS Elastic Beanstalk updates the configuration set associated with the running environment and sets the specified configuration options to the requested value.
I created a config file under .ebextensions folder that had the following content:
option_settings:
- namespace: aws:rds:dbinstance
option_name: DBSnapshotIdentifier
value: <name-of-snapshot>
Upload and deploy and it will create a new RDS db using this snapshot.
Hot-swapping out the data tier within an environment is discouraged because it breaks down the integrity of the environment. What you want to do is clone the environment, with a restored snapshot of the RDS instance. This means you'll have an identical environment with a different url 'host', and if everything went without a hitch, then you can swap environment urls in order to initiate a DNS swap.
After the swap happens and everything is good to go, you can proceed to deflate the old environment
Follow the steps in the resolution to:
Use an Elastic Beanstalk blue (environment A)/green (environment B) deployment to decouple an RDS DB instance from environment A.
Create a new Elastic Beanstalk environment (environment B) with the necessary information to connect to the RDS DB instance.
check out the official answer below for more detailed solution
https://aws.amazon.com/premiumsupport/knowledge-center/decouple-rds-from-beanstalk/?nc1=h_ls
Related
I would like to make a step towards a no-downtime continuous deployment of my application.
I have an app running on an EC2 instance that connects to the aurora database. During the deployment I need to run the database migration scripts and update the app running on EC2. How can I update both of them without causing any down time? I probably can configure Elastic Beanstalk/CodeDeploy to update the EC2 instance in such a way that for a while I will in fact have 2 instances of my app running on 2 separate EC2 instances, but that still gives me only one instance of the database. If I run my migration scripts, this may assassinate one of the instances of my application and if the deployment for some reason fails, I might not be able to revert the changes done to the database.
So basically the question is: what is the right way to apply the SQL migration scripts without causing any downtime?
That would depend on your specific situation and type of DB migration. One route you can follow, taken directly from AWS documentation is :
Clone your Aurora DB, using AWS provided API
Apply your migration script to the new DB
Deploy your new source code version to a new Elastic Beanstalk environment
Test your new source code with new DB
Swap the two environment CNAME using the api provided by AWS or from your DNS, you may want to synchronize the data changes from old DB to new DB before doing so
When rebuilding an elastic beanstalk environment, EB automatically recreates a new and associated RDS instance.
Once associated, RDS instances cannot be dissociated from an EB environment.
I have a snapshot of the previous RDS prior to the rebuild.
You cannot restore RDS snapshots to an existing RDS instance.
How then, can I rebuild the environment with my desired snapshot attached? Or, how can I use my existing snapshot, or how can I migrate the existing snapshot data to the new database (I tried a data export with create schema's but lacked permissions on the import). Any appropriate but ideally simple option will do.
If you have a snapshot of your RDS DB, you can create a new environment with it. For this, you need to specify the DBSnapshotIdentifier option setting.
Create a file .ebextensions/rds_builder.config in the root of your project
Add the following:
option_settings:
aws:rds:dbinstance:
DBSnapshotIdentifier: <snapshot ID here>
EDIT:
You can also create a new environment using a saved configuration template of the present one. It is likely that this saved template will contain information in the aws:rds:dbinstance (since you have associated your present environment with an RDS), so you would need to basically modify this bit to point to your snapshot. This should work, and is probably the better approach.
The Elastic Beanstalk environment is running on t1.micro & db.t1.micro, where we tried to update the rds to db.m1.small instance. This configuration change has been made on the Elastic Beanstalk and it is on updating state for around 4 hours, we thought AWS stuck somewhere internally. In this meantime, the AWS has not updated the Trace information. In order to retain the environment back (rollback of configuration update operation), we have aborted the environment configuration update. This has ended up on invalid state with the health turned to grey. This because AWS will not allow creating t1 environment nowadays, however, the rollback is trying to bring back the older t1 setup with an error--> RDS does not support creating a DB instance with the following combination: DBInstanceClass=db.t1.micro, Engine=mysql, EngineVersion=5.6.37, LicenseModel=general-public-license. For supported combinations of instance class and database engine version.
Any suggestion to bring back the environment to green would be really helpful.
Yes, with the source of the snapshot we could able to create a new EBS instance. The only problem we faced during the snapshot to clone an instance is the application level configuration file change not done. BTW there is no proper root cause for the AWS DB upgrade failure from AWS.
I know this has been partially answered in a bunch of places, but the answers are so.. all over the map, dated and not well explained. I'm looking the best practice as of February 2016.
The setup:
A PHP-based RESTful application service that lives in an EC2 instance. The EC2 instance uses S3 for uploaded user data (image files), and RDS MySql for its DB (these two points aren't particularly important.)
We develop in PHPStorm, and our source control is GitHub. When we deploy, we just use PHPStorm's built-in SFTP deployment to upload files directly to the EC2 instance (we have one instance for our Staging environment, and another for our Production environment). I deploy to Staging very often. Could be 20 times a day. I just click on a file in PHPStorm and say 'deploy to Staging', which does the SFTP transfer. Or, I might just click on the entire project and click 'deploy to Staging' - certain folders and files are excluded from the upload, which is part of PHPStorm's deployment configuration.
Recently, I put our EC2 instance behind a Load Balancer. I did this so that I can take advantage of Amazon's free SSL offering via the Certificate Manager, which does not support individual EC2 instances.
So, right now, there's a Load Balancer with only a single EC2 instance behind it. I maintain an Elastic IP pointing to the EC2 instance so that I can access it directly (see my current deployment method above).
Question:
I have not yet had the guts to create additional (clone) EC2 instances behind my Load Balancer, because I'm not sure how I should be deploying to them. A few ideas came to mind, but they're all pretty hacky.
Given the scenario above, what is currently the smoothest and best way to A) quickly deploy a codebase to a set of EC2 instances behind a Load Balancer, and B) actually 'clone' my current EC2 instance to create additional instances.
I haven't been able to really paint a clear picture of the above in my head yet, despite the fact that I've gone over a few (highly technical) suggestions.
Thanks!
You need to treat your EC2 instance as 100% dispensable. Meaning, that it can be terminated at any time and you should not care. A replacement EC2 instance would start and take over the work.
There are 3 ways to accomplish this:
Method 1: Each deployment creates a new AMI image.
When you deploy you app, you deploy it to a worker EC2 instance whose sole purpose is for "setup" of your app. Once the new version is deployed, you create a fresh AMI image from the EC2 instance and update your Auto Scaling launch configuration with the new AMI image. The old EC2 instances are terminated and replaced with the new code.
New EC2 instances have the recent code already on them so they're ready to be added to the load balancer.
Method 2: Each deployment is done to off-instance storage (like Amazon S3).
The EC2 instances will download the recent code from Amazon S3 and install it on boot.
So to put the new code in action, you terminate the old instances and new ones are launched to replace them which start using the new code.
This could be done in a rolling-update fashion, or as a blue/green deployment.
Method 3: Similar to method 2, but this time the instances have some smarts and can be signaled to download and install the code.
This way, you don't need to terminate instances: the existing instances are told to update from S3 and they do so on their own.
Some tools that may help include:
Chef
Ansible
CloudFormation
Update:
Methods 2 & 3 both start with a "basic" AMI which is configured to pull the webpage assets from S3. This AMI is not changed from version-to-version of your website.
For example, the AMI can have Apache and PHP already installed and on boot it pulls the .php website assets from S3 and puts them in /var/www/html.
CloudFormation works well for this. In addition, for method 3, you can use cfn-hup to wait for update signals. When signaled, it'll pull updated assets from S3.
Another possibility is using Elastic Beanstalk which could be used to manage all of this for you.
Update:
To have your AMI image pull from Git, try the following:
Setup an EC2 instance with everything installed that you need to have installed for your web app
Install Git and setup a local repo ready to Git pull.
Shutdown and create an AMI of your instance.
When you deploy, you do the following:
Git push to GitHub
Launch a new EC2 instance, based on your AMI image.
As part of the User Data (specified during the EC2 instance launch), specify something like the following:
#!/bin/sh
cd /git/app
git pull
; copy files from repo to web folder
composer install
When done like this, that user data acts as a script which will run on first boot.
I am new to AWS EB and I am trying to figure out how to backup and restore an entire EB environment. I created an AMI based on the EC2 instance generated by EB, and took a snapshot of RDS, also created by EB.
The problem I have is, how do I restore it, assuming that this is the correct approach of backup. Also, I am doing it manually, shouldn't there be an automated way of doing this within EB? By the way, when I created the AMI, it destroyed the source and the EB just created a new EC2 instance without all my changes.
How do I save & restore configuration changes to my application that impact both filesystem and database?
Unfortunately, Amazon AWS Elastic Beanstalk (EB) does not support restoring databases that contain live data, if those databases were created with EB. If you reload (AKA AWS "deploy") the EB saved configuration, you get a blank database!
I called them and they told me to create the RDS DB separately and update the application code to connect to the DB once you know it's name. If you restore the RDS DB it will have a new name too! So you have to update your code again to connect to it.
Also, if you code and environment is fine, but you want to restore your database, again it will have a new name and you will need to change your code.
How to change your code easily and automatically deploy it is a whole other question for which I don't have an answer yet.
So basically the RDS DB provisioning within Elastic Beanstalk has very limited uses, maybe coding and debugging and testing, but not live production use. :(
This is as of Jan 2015.
First go into your EB environment and save the current config. You should go to a running EC2 instance created by EB and make an Image. Then use that new AMI ID by going to the EB configuration and setting it. It will rebuild the environment tearing down all running instances and creating new ones.
For your RDS instance you should make a backup and restore with a new instance name as the docs say you will lose it if the environment is destroyed. You should probably just manually set the environment variables like RDS does and setup the proper security groups between RDS and EC2.
One option I think could work is just renaming the RDS instance name as the environment seems to break and then destroy the environment and create a new one with an attached RDS instance and then destroy that one and rename the old one to the new one's name which may work.
As always make proper backups before proceeding with any of these ideas.