第13章ハイブリッドマルチクラウドのデジタルソリューション開発

In recent years, container management services, which encapsulate an application with the necessary operating system libraries for it to operate, have become one of the key innovations that have transformed the use of cloud infrastructures. In a nutshell, the container is a way to encapsulate an application with any operating system’s library that is required for the application to operate. By using a container, the developer is not worried about the environmental mismatch between the environment where the application was developed and the environment where the application is run. This container can be run on top of any Linux kernel that provides support to the container runtime. Figure 13.7 shows how a container runs in a regular compute environment. It is also important to point out that the container technology is different from the virtualization technology used in virtual machines.

On the cloud environment, the container management service allows the user to deploy, operate, and scale any containerized application. It also includes several necessary components that help the user manage their containerized application better, such as the following:

• The container registry (CR), or the registry where the user can version control each container image that they deployed into the cloud environment. The user can usually manage the container using image metadata such as namespace, image name, or image tags.

• The base container image, which is the foundational layer of a container provided by the cloud provider to build an application. The image is mostly up-to-date with secure patches and packages that allow the user to update their application with the latest security update.

• The Kubernetes environment, or Kubernetes (K8S) service, which is the most popular container orchestration system. This is a managed service that is usually provided by the cloud provider to allow the user to scale their containerized application in a Kubernetes environment. The K8S environment is one of the key systems to run a hybrid cloud environment where the user can run applications from both their local and cloud environment.

Figure 13.8 shows a simple workflow to deploy a containerized application into Azure Cloud Environment. Architecting a hybrid cloud solution requires strong technical expertise in application development and containerized application, and it also requires deep knowledge of cloud solutions. The details on how to do it correctly will not be covered in this section. However, the hybrid solution should be the target for any user on their journey of migrating their application into the cloud.

For deployment, organizations can use containers or virtual machines. How do you decide which technology is more appropriate? Containers have more scalability and are practical if you’re working with multiple environments and you want to package and run your applications in a manner that is predictable with repetition from one environment to the next. Virtual machines (VM) provide more environmental control and are practical if you need to use the same physical machine to install more than one operating system, as well as create more than one environment. Another consideration is the speed of software development. It is faster and easier to build and test new features on containers compared to VMs. However, VMs provide better security. While there’s a lot to consider when deciding on containers versus VMs, both technologies offer important benefits, providing organizations with critical resources for deployment.

Today, database or any data management system is the heart of any application. However, managing a database is usually a difficult task as the data can be growing oversized both in size and in complexity. For this reason, most cloud providers provide several managed database services for any application that runs inside and outside of the cloud environment. There are two popular database management services:

• A relational database service (RDS), in which the relationship between data is strictly managed. The data can be managed under a predefined data schema. This is the most common type of database that most developers are familiar with. Some popular examples of this type of database are Oracle DB, MySQL, or PostgreSQL.

• A NoSQL database, in which the relationship between data is not strictly managed. The data can be managed under key/value pair. This type of database has become popular in recent years with monitoring applications where the data needs to be written and captured quickly. Some popular examples of this type of database are MongoDB Atlas and Cassandra DB.

The access pattern for these services is similar to how any application access to any managed database. Different secure authentication and authorization methods can be configured through the CLI or web console by the user and the application can access the database from inside or outside of the cloud environment.