AWS RDS cross account snapshot restoration

Many a times you may have faced problem where your production infra is on different AWS account and non prod on different account and you are required to restore the RDS snapshot to non prod account for testing.

Recently I got a task to restore my prod account RDS snapshot to a different account for testing purpose. It was a very interesting and new task for me. and I was in an awe, how AWS thinks about what all challenges we may face in real life and provides a solution to it.

For those who are not aware about RDS, I can brief RDS as a relational database service by Amazon Web Services (AWS), it is a managed service so we don’t have to worry about the underlying Operating System and Database software installation, we just have to use it.

Amazon RDS creates a storage volume snapshot of your DB instance backing up the entire DB instance and not just individual database. As I told you, we have to copy and restore an RDS snapshot to a different aws account. There is a catch!, you can directly copy an aws snapshot to a different region in same aws account, but to copy to a different aws account you need to share the snapshot to aws account and then restore from there, so lets begin.

To share an automated DB snapshot, create a manual DB snapshot by copying the automated snapshot, and then share that copy.

Step 1: Find the snapshot that you want to copy, and select it by clicking the checkbox next to it’s name. You can select a “Manual” snapshot, or one of the “Automatic” snapshots that are prefixed by “rds:”.

Step 2: From the “Snapshot Actions” menu, select “Copy Snapshot”.

Step 3: On the page that appears: Select the target region. In this case, since we have to share this snapshot with another aws account we can select existing region.

  • Specify your new snapshot name in the “New DB Snapshot Identifier” field. This identifier must not already be used by a snapshot in the target region.
  • Check the “Copy Tags” checkbox if you want the tags on the source snapshot to be copied to the new snapshot.
  • Under “Encryption”, leave “Disable Encryption” selected.
  • Click the “Copy Snapshot” button.

Step 4: Once you click on “Copy Snapshot”, you can see the snapshot being created.

Step 5: Once the manual snapshot is created, select the created snapshot, and from the “Snapshot Actions” menu, select “Share Snapshot”.

Step 6: Define the “DB snapshot visibility” as private and add the “AWS account ID” to which we want to share the snapshot and click on save.

Till this point we have shared our db snapshot to the aws account where we need to restore the db.
Now login to the other aws account and go to RDS console and check for snapshot that was shared just recently.

Step 7: Select the snapshot and from the “Snapshot Actions” menu select “Restore Snapshot”.

Step 8: From here we just need to restore the db as we do normally. Fill out the required details like “DB Instance class”, “Multi-AZ-Deployment”, “Storage Type”, “VPC ID”, “Subnet group”, “Availability Zone”, “Database Port”, “DB parameter group”, as per the need and requirement.

Step 9: Finally click on “Restore DB instance” and voila !!, you are done.

Step 10: You can see the db creation in process. Finally, you have restored the DB to a different AWS account !!

Conclusion:

So there you go. Everything you need to know to restore a production AWS RDS into a different AWS account. That’s cool !! Isn’t it ?, but I haven’t covered everything. There is a lot more to explore. We will walk through RDS best practices in our next blog, till then keep exploring our other tech blogs !!.

Image source: https://unsplash.com/photos/lRoX0shwjUQ


Why I love pods in Kubernetes? Part – 1

When I began my journey of learning Kubernetes, I always thought why Kubernetes has made the pod its smallest entity, why not the container. But when I started diving deep in it I realized, there is a big rationale behind it and now I thank Kubernetes for making the Pod as an only object, not containers.

After being inspired by the working of a Pod, I would like to share my experience and knowledge with you guys.

Image result for kubernetes pod memes

What exactly Pod means?

The literal meaning of pod means the peel of pea which holds the beans and following the same analogy in Kubernetes pod means a logical object which holds a container or more than one container.
The bookish definition could be – a pod represents a request to execute one or more containers on the same node.

Why Pod?

The question that needs to be raised why pod?So let me clear this, pods are considered the fundamental building blocks of Kubernetes, because all the Kubernetes workloads, like DeploymentsReplicaSets or Jobs are eventually expressed in terms of pods.

Pods are the one and only objects in Kubernetes that results in the execution of containers which means No Pod No Containers !!!

Now after the context setting over pod I would like to answer my beloved question:- Why Pod over container??

My answer is why not 🙂 

Let’s take an example, suppose you have an application which generates two types of logs one is access log and other logs are error log. Now you have to add log shipper agent, In case of the container, you will install the log shipper in the container image. Now you got another request to add application monitoring in the application. So again you have to recreate the container image with APM agent in it.
Don’t you think this is quite an untidy way to do it? Of course, it is, why I have to add these things in my application image, it makes my image quite bulky and difficult to manage.

What if I tell you that Kubernetes has its own way of dealing situations like this. 

Yup the solution is a sidecar. Just like in real life if I have a two sitter bike and I want to take 3 persons on a ride, So I will add a sidecar in my bike to take 2 persons together on the ride.
In a similar fashion, I can do the same thing with Kubernetes as well. To solve the above problem I will just create 3 containers (application, log-shipper and APM agent) in the same pod. Now the question is how they will access the data between them and how the networking magic will happen.
The answer is quite simple containers withing the pod can share Pod IP address and can listen on localhost. For volume, we can share volumes also across the containers in a pod.

The architecture would be something like this:-

Related image

Now another interesting query arises that when to use sidecar and when not.

Just as shown in the above image we should not keep application and database as a sidecar in the same pod. The reason behind it is Kubernetes does not scale a container it scales a pod. So when autoscaling will happen it scales the application as well as database which could not be required.

Instead of that, we should keep log-shippers, health-check containers and monitoring agent as a sidecar because anyhow application will scale these agents also needs to be scaled with the application.

Now I am assuming you are also madly in love with the pods.

For diving deep in the pod stay tuned for the next part of this blog Why I love pods in Kubernetes? Part – 2. In my next part, I will discuss the different phases and lifecycle of the pod and how pod makes our life really smooth.
Thanks for reading, I’d really appreciate any and all feedback, please leave your comment below if you guys have any feedback.

Cheers till the next time.

Docker-Compose As A Bundled Application

When docker was released as a new containerization tool, it took the market by a storm. With its lightweight images, multi-os support, and ability to ship containers, it’s popularity only roared. I have been using it for more than six months now, I can see why it is so. Hypervisors, another type of virtualizing tools,  have been hard on hardware. Which means they require a lot of resources to run. This increases the cost of running applications way more than those running on containers. This is the problem docker solved and hence, it’s popularity. Docker engine just sits on host OS and translates the instructions from an application to the underlying OS. It does not need one extra layer of virtual OS, just the binaries and libraries of application bundled in the image. Right? Now, hold on to that thought. We all have been working with docker and an extension with docker-compose. Why? Because it makes our job easy, We are spared from typing hundreds of ad-hoc commands in terminal to set up a slightly or very complicated application with certain dependencies. We can just describe it in a `docker-compose.yml` file and our job is done. However, the problem arises when we have to share that compose file:

  • Other users might need to use the file in a different environment, so they will need to edit all the values pertaining to their need, manually, and keep separate compose files for each environment.
  • Troubleshooting various configuration issues can be a tedious task since there is no single place where the configuration of the application can be stored. Changes will have to be made in the file.
  • This also makes communication between Dev and Ops team more tricky than it has to be resulting in communication gap and time wastage.

To have a more clear picture of the issue, we can have look at the below image:

We have compose file and configuration for separate environments, we make changes according to environment needs in different compose files, which could be a long manual task depending on the size of our project.


All of this points to the fact that there is no way to bundle the applications that use efficiently-bundled docker images. See the irony here? Well, there “was” no way, until there was. Enter ‘docker-app’. This, relatively, new tool is the answer to packaging docker-compose applications. I came across it when I was, myself, struggling to re-use a docker-compose application I had written in another environment. As soon as I read about it, I had to try it, which I did and loved. It made the task much easier as it provided a template of compose file and a key-value store for environment dependent parameters.


Now, we have an artefact with extention of ‘.dockerapp’. We can pass configuration values either through CLI or files or both and it will render compose file according to those values.

Let us now go through an example of how the docker app works. I am going to deploy a dummy application Spring3hibernate from Opstree Github repository in QA env and later in PROD by making simple configuration changes.
Installing docker-app is easy, though, there is one thing one should keep in mind: it can be installed as a plugin in docker-CLI or as standalone CLI tool itself. I will be installing it as a standalone CLI tool on linux. If you wish to install it as a plugin to docker-CLI and/or on another OS, visit their Github page: https://github.com/docker/app (Also, please visit github page for basics)
Before continuing, please ensure you have docker-CLI and docker-compose installed.
Please follow below steps to install docker-app:

$ export OSTYPE="$(uname | tr A-Z a-z)"
$ curl -fsSL --output "/tmp/docker-app-${OSTYPE}.tar.gz" \
"https://github.com/docker/app/releases/download/v0.8.0/docker-app-${OSTYPE}.tar.gz"
$ tar xf "/tmp/docker-app-${OSTYPE}.tar.gz" -C /tmp/
$ install -b "/tmp/docker-app-standalone-${OSTYPE}" /usr/local/bin/docker-app

Create a new directory in your home, we’ll call it app home:

$ cd ~
$ mkdir spring3hibernate-app
$ cd spring3hibernate-app/

Now, clone the app from Opstree Github repository. This app needs only mysql as a dependency.

$ git clone https://github.com/opstree/spring3hibernate.git

We need to update database properties file and nginx config file with below contents respectively:

$ vim ~/spring3hibernate-app/spring3hibernate/src/main/resources/database.properties

Replace below content over there:

database.driver=com.mysql.jdbc.Driver
database.url=jdbc:mysql://mysql:3306/employeedb
database.user=admin
database.password=password
hibernate.dialect=org.hibernate.dialect.MySQLDialect
hibernate.show_sql=true
hibernate.hbm2ddl.auto=update
upload.dir=c:/uploads

For nginx conf file:

$ vim ~/spring3hibernate-app/spring3hibernate/nginx/default.conf
server {
    listen       80;
    server_name  localhost;

    location / {
        stub_status on;
        proxy_pass http://springapp1:8080/;

    }
# redirect server error pages to the static page /50x.html
    error_page   500 502 503 504  /50x.html;
    location = /50x.html {
        root   /usr/share/nginx/html;
    }

}

Move ‘default.conf’ to ~/spring3hibernate-app/spring3hibernate/nginx/conf/qa/ as we have different conf file for PROD which goes to ~/spring3hibernate-app/spring3hibernate/nginx/conf/prod/

upstream s3hbackend {
    server springapp1:8080;
    server springapp2:8080;
}
server {
       listen 80;
       location / {
           stub_status on;
           proxy_pass http://s3hbackend;
       }
  
       # redirect server error pages to the static page /50x.html
       error_page   500 502 503 504  /50x.html;
       location = /50x.html {
           root   /usr/share/nginx/html;
       }

}

This is the configuration for the nginx load balancer. Remember this, we’ll use it later. Let’s create our docker-app now, make sure you are in the app home directory
when executing this command:

$ docker-app init --single-file s3h

This will create a single file named s3h.dockerapp which will look like this: 

# This section contains your application metadata.
# Version of the application
version: 0.1.0
# Name of the application
name: s3h
# A short description of the application
description:
# List of application maintainers with name and email for each
maintainers:
  - name: ubuntu
    email:


---
# This section contains the Compose file that describes your application services.
version: "3.6"
services: {}


---
# This section contains the default values for your application parameters.

{}

As you can see this file is divided into three parts, metadata, compose, and parameters. They are all in one file because we used –single-file switch. We can divide them up in multiple files by using docker-app split command in app home directory, docker-app merge will put them back in one file. Now, for QA, we have the following configuration for s3h.dockerapp file:

version: 0.1.0
name: s3h
description:
maintainers:
  - name: atbk5
    email: adeel.ahmad@opstree.com


---
version: "3.7"
services:
  mysql:
    image: mysql:5.7
    container_name: mysql
    environment:
      MYSQL_ROOT_PASSWORD: ${mysql.env.rootpass}
      MYSQL_DATABASE: ${mysql.env.database}
      MYSQL_USER: ${mysql.env.user}
      MYSQL_PASSWORD: ${mysql.env.userpass}
    restart: always
    networks:
      - backend
    volumes:
      - db_data:/var/lib/mysql


  spring1:
    depends_on:
      - mysql
    build:
      context: ./spring3hibernate/
      dockerfile: Dockerfile
    container_name: springapp1
    restart: always
    networks:
      - backend
      - frontend


  spring2:
    depends_on:
      - mysql
    build:
      context: ./spring3hibernate/
      dockerfile: Dockerfile
    container_name: springapp2
    restart: always
    networks:
      - backend
      - frontend
    x-enabled: ${spring.app2}


  nginx:
    depends_on:
      - spring1
    image: nginx:alpine
    container_name: proxy
    restart: always
    networks:
      - frontend
    volumes:
      - ${nginx.conf}:/etc/nginx/conf.d
    ports:
      - ${nginx.port}:80
    x-enabled: ${nginx.status}


networks:
  frontend:
  backend:


volumes:
  db_data:


---
mysql:
  env:
    rootpass: password
    database: employeedb
    user: admin
    userpass: password
nginx:
  conf: /home/ubuntu/dockerApp/spring3hibernate/nginx/conf/qa
  port: 81
  status: true
spring:
  app2: false

As mentioned before, first part contains app metadata, second part contains actual compose file with lots of variables, and last part contains values of those variables. Special mention here is x-enabled variable, docker-app provides functionality to temporarily disable a service using this variable. Now, try a few commands:

$ docker-app inspect

It will produce summary of whole app.

$ docker-app render

It will replace all variables with their values and will produce a compose file

$ docker-app render --set nginx.status=”false”

It will remove nginx from docker-app compose as well as deploy

$ docker-app render | docker-compose -f - up

It will spin up all the containers according to rendered compose file. We can see the application running on port 81 of our machine.

$ docker-app --help

To check out more commands and play around a bit.
At this point, it will be better to create two directories in app home: qa and prod. Create a file in qa: qa-params.yml. Another file in prod: prod-params.yml. Copy all parameters from above s3h.dockerapp file to qa-params.yaml (or not). More importantly, copy below changes in parameters to prod-params.yml

mysql:
  env:
    rootpass: password
    database: employeedb
    user: admin
    userpass: password
nginx:
  conf: /home/ubuntu/dockerApp/spring3hibernate/nginx/conf/prod
  port: 80
  status: true
spring:
  app2: true

We are going to loadbalance springapp1 and springapp2 in PROD environment, since we have enabled springapp2 using x-enabled parameter. We have also changed nginx conf bind path to the new conf file and host port for nginx to 80 (for Production). All so easily. Run command:

$ docker-app render --parameters-file ./prod/prod-params.yaml

This command will produce a compose file ready for production deployment. Now run:

$ docker-app render --parameters-file ./prod/prod-params.yml | docker-compose -f - up

And production is deployed … Visit port 80 of your localhost to verify. What’s more exciting is that we can also share our docker-apps through docker hub, we can tag the app and push it to our remote registry as images after logging in:

$ docker login

Provide your username and password for docker hub, create an account if not yet created.

$ docker-app push --tag atbk5/s3h.dockerapp:latest

If we wish to upload additional files as well, we will have to split our project using docker-app split and put additional files in the directory before pushing. The additional files will go as attachments which can be accessed later.

Conclusion

With the arrival of docker app, our large, composite, and containerized applications can also be shipped and re-used as images. That is cool. But there’s something cooler which we haven’t explored yet. Deploying our docker-apps on kubernetes with the goal of exploring how far in management, and how optimal in delivery, we can go with our applications. Let’s keep this as a topic for the next blog. Until then, have a nice one. 🙂

Image Source: https://reflectoring.io/externalize-configuration/