Introduction to Docker and Containers- Learning Simple

Introduction to Docker and Containers- Learning Simple

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  Introduction to Docker & Containers StartLearning Simple – Part-1 By : Sandeep Hijam
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  Introduction I have recentlystarted reading and understanding the Docker and Container hype which has been here for quite some time. Viewed lots of YouTube videos, research lots of articles, everybody keeps on speaking the same thing repeatedly. All those are informative but for me, they are not so easy to digest. If we are starting out it is very difficult to understand the technical jargon.
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  Running Market Whenever wehear or ask what is docker and container the most common answer that we received is "Machine independent Micro-service application. Now as laymen we will start searching for what is this microservice, then we will get the answer to be somewhat like "De-coupling / De-centralising the application and making it into small -small module". BUT why it needs to be so technical can it not made to be more simple.
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  Earlier Knowledge Earlier howdo we make the software application, we write a bunch of code into our computer then compile and built the application. This complete code is either distributed in the form of Application EXE or Web page/application right. I believe everybody is following till now. Once we receive this EXE/ Web application we either install or host it on the customer machine and our production is done. As the technology progress, we shifted from application install/ hosting on a single on-premise server to multi-VM (Virtual Machine) application installation/hosting. Till here we all are comfortable and there was no confusion in terms of the technology shift.
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  Compute More W ha t i s c l o u d c o m p u t i n g t h e n , Well there are many definitions which describe the services along with their pros and cons? But let me say it like this. It is nothing but an Interconnected virtual machine running anywhere and accessible from everywhere with multiple services running on top of it. Now with the arrival of cloud computing, the technology is shifting at a very rapid speed. It is now becoming impossible to keep ourselves at that pace. So before we go to container and docker let's understand what is cloud computing.
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  How Connected Now let'scome back to the original topic what is Container and docker. Both this word will always be interconnected just like the old-days of application/web server and the project code which might be written in any language. So in the early time, we need to set up the application/webserver to run our code if we do not have this then the project will not run. Some of the servers are IIS, Apache web server, Apache Tomcat, etc. In the very same way, w e n e e d t o i n s t a l l a d o c k e r t o r u n o u r c o n t a i n e r c o d e . So for simple understanding, I would keep docker just like a web server. Yes, I know it not apple to apple comparison docker does much more than just running the application.
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  Containers Now then wh a t i s t h e c o n t a i n e r , it is just our normal application code what we have been writing. Yes, that is it. Ok, let's see in-depth, now we have the docker installed on the system, and then we write the code on our favorite code editor like visual studio, Notepad++, etc. after this we compile the application and make a docker image which is now called as a container image. I know what you might be thinking if these are the same why use container why don't we follow the old school. To understand this let me take you to micro-services, what it really is and how we are really benefitting from this shift.
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  Micro-services I would saythis micro-service is not new we have been using for decades. It is just been much more beneficial with the arrival of cloud computing. I think we can compare this with an old digit magazine disc application where we see all the SWF (Flash files) separated into multiple files. Also in the modern development context, I will compare with the popular PHP base WordPress application. But this is not the full microservices we are just referring to the way the files are structure and arrange. So Now let's see what is this microservices. As the name suggests, we have to divide our application function/feature into multiple services. How do we divide into small functions? Let me compare it with the old day's application development model
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  The Old-Way Step 1: Step2: Step 3: Step 4: Step 5: Understand the requirement/customer problem. Design the solution by dividing it into features or functions that the customer/problem required. We select the technology and then set up the development environment e.g .Net / Java programming language is chosen and then set up the environment. Develop - Test and Deploy the application using the selected language. This is an additional step if the problem/requirement demands the 3rd party Integration either API base or any other we do that by accessing and understanding the exposed API. In the old development model, we follow the below step.
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  The New-Way Step 1: Step2: Step 3: Requirement gathering or understanding the problem Designing the solution by segregating the features and functions required Here we choose the team/teams and not the programming language as in the above. Also, we instruct the team to write the code with API integration in mind from the start. So each team member will use their favorite programming language and do not share the same environment. In the old development model, we follow the below step. All the team members can choose the function/features that they want to develop using their comfortable language. Now each one of them will run the functions/features separately and check it.
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  Reality Check Then thereis a question of how does each one of them will check the features and functionality of the complete application if they are just developing their own part. Now that's the beauty of this development approach. So let me say in this way, remember I compared earlier on this article that Microservices is like PHP based WordPress Application. Each and everyone will either developed temporary UI or used an Open Source resource like POSTMAN to check the function and the features that they have been developing. Once the function is developed the other team person can just be used the same function in the form of API calls. is it confusing lets me explain like this There are 3 developers developing 3 features or functions separately Developer 1: Developed the function for form entry. Developer 2: Developed the function of extracting the graph from another server. Developer 3: This person developed the front end UI of the application Scenario
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  Scenario – In-depth Allthese developers are developing using their comfortable programming language. All of them are developing at their own pace with no dependencies on each other. Now once each of them has completed their task they will communicate saying their functions are ready. At this time the Developer 3 or UI in our example will just use the API call on the UI page to perform those functions. He does not need to write any code on Developer 1 or developer 2 behalf. In this scenario for communication among the team, we use DevOps. DevOps is another topic which I will not cover in this, just understand that in the microservice scenario we use DevOps to communicate among team members. So now we have many independent application codes connected together to form an application which is called Micro-services. To re- cape, Microservices are nothing but interconnected small-small applications developed using different technologies and making bigger Applications.
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  Conclusion Now ComingBack to Container and Docker, as in microservices we are developing an application using different languages and technologies then their dependencies will also exist right. To overcome this Docker will generate Images with all the technical dependencies of the applications and kept it somewhere to access. Here comes the beauty of cloud computing, As it is accessible from anywhere if the compile images are placed at the cloud location which make it easily accessible. One such location is the docker hub where we store the docker images. Now anyone who wants to access these images they can easily take the docker hub image URL and host it anywhere or use it
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  Summary Docker is theapplication that we need to installed on our machine to generate Container Images We can take docker as old days web or application server for easy understanding Microservices approach is interconnected small-small application and making it into a bigger application We use API to connect among the microservices application
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  About Me He ispassionate and well-organized leader and likes to be on top of the agenda. He is having a dynamic management career with strong skills in relationship building, problem-solving, program management, and planning. Digital Transformation Leader with competency in transformation/migration of businesses in Public cloud. Helping Customers/Partners in Cloud Consulting, Cloud Adoption, Cloud Transformation , Cloud Security, Cloud Governance and Management. 10 year’s hands-on experience on Presales and Bid Management Activities. An extensively experience resource in defining technology and solution roadmap for enterprise customers. SANDEEP HIJAM ( MCP, ITIL, Azure Certified Architect, with 14 Years Industry experience ) https://bit.ly/34Hp0ER https://www.facebook.com/sandeephijam/ +91-7838357977