Part 1 | RTF Primer | Virtualization and Containerization
Introduction to Runtime Fabric Deployment Model
In this section, the speaker introduces the runtime fabric deployment model and explains its relevance in deploying containerized Mule applications in a Kubernetes cluster. The concepts of virtualization, containerization, and Kubernetes are briefly discussed.
Virtualization and Containerization
- Virtualization is the foundation of cloud-based technologies.
- It allows for the hosting of multiple operating systems on a single hardware device.
- Virtual machines (VMs) are created using a hypervisor to provide an isolated environment for each operating system.
- Containers are lightweight alternatives to VMs that share the host OS kernel but have their own isolated runtime environments.
Basics of Kubernetes
- Kubernetes is an open-source container orchestration platform used for automating deployment, scaling, and management of containerized applications.
- It provides features like load balancing, service discovery, and automatic scaling.
- Kubernetes uses a declarative approach through YAML files to define application deployments and configurations.
Challenges with Resource Consumption
This section discusses challenges related to resource consumption when deploying multiple applications on a single machine or operating system.
Conflicts in Resource Consumption
- Deploying multiple applications that require exclusive access to certain resources can lead to conflicts.
- Examples include conflicting versions of software dependencies or incompatible software running simultaneously on a single machine.
Isolation of Resources
- Virtualization helps resolve conflicts by providing isolation of resources for each application or operating system.
- Each virtual machine or container has its own dedicated set of resources without interfering with others.
Understanding Virtualization
This section explains the concept of virtualization and how it enables hosting multiple operating systems on a single hardware device.
Hypervisor and Virtual Machines
- Virtualization is achieved using a hypervisor, which tricks the guest operating system into believing it has exclusive access to the underlying hardware.
- There are two types of hypervisors: Type 1 (bare metal) and Type 2 (installed on an operating system).
- Type 1 hypervisors are installed directly on the hardware, while Type 2 hypervisors are installed on top of an existing operating system.
Network Isolation and Access
This section discusses network isolation and access in virtualized environments.
Virtual Networks
- In a virtualized environment, each guest operating system gets its own virtual network interface with its own set of ports and IP addresses.
- The hypervisor ensures that communication between the host OS, guest OS, and external machines is properly routed.
External Access to Guest Operating Systems
- To access web servers running on guest operating systems from external machines within the same physical network, routing rules or load balancers may be required.
Optimization through Resource Efficiency
This section highlights the need for resource efficiency when running applications in virtualized environments.
Overhead of Full-Fledged Operating Systems
- Running a full-fledged operating system for a single application can be resource-intensive and inefficient.
- Operating systems have components that may not be necessary for specific applications, such as UI drivers or sound drivers.
Optimizing Resource Consumption
- To optimize resource consumption, it is important to minimize unnecessary software components and allocate resources based on application requirements.
- Containerization provides a lightweight alternative by sharing the host OS kernel while isolating runtime environments for individual applications.
New Section
This section discusses the modification of a virtualization diagram by removing the guest OS kernel and hypervisor. It introduces the Docker runtime and Docker Daemon as replacements for managing resources.
Modifying the Virtualization Diagram
- The guest OS kernel and hypervisor are removed from the virtualization diagram.
- The Docker runtime and Docker Daemon are introduced to manage resources in place of the removed components.
- The Docker runtime runs an image OS, which is a minimal version of a full-fledged operating system with only essential binaries and libraries required to run applications.
- The image OS, when run on the Docker runtime, takes the form of a container.
- Resource requests from containers are routed to the host operating system's kernel via the Docker Daemon.
New Section
This section explains how image OS functions as a lightweight version of an original operating system, reducing boot time for containers.
Image OS and Container Creation
- The image OS is a lightweight version of an original operating system like Windows or Linux, containing minimal libraries and binaries.
- Containers made out of image OS have reduced boot time as they rely on the host operating system's kernel instead of having their own kernel.
- All docker images start with a base image that can be retrieved from public container registries.
- A new custom image can be created by adding an application and its associated libraries on top of a base image using commands specified in a Docker file.
- The custom image can be published to a container registry using a Docker client.
- In the docker runtime, an image can be pulled from the registry and run to create a container.
New Section
This section highlights that containers have their own isolated disk space, RAM, ports, and IP address. It emphasizes storing persistent data outside the container.
Container Isolation and Persistent Data
- Containers have their own isolated disk space, RAM, ports, and IP address.
- Any data stored on the persistent storage attached to a container will be wiped off when the container is stopped or crashed.
- To store persistent data, it should be done outside the file system of the container on some other persistent storage.
- Docker relies on resource isolation techniques like name spacing and control groups to achieve resource isolation.
- Name spacing isolates specific segments of resources such as hard disks or networks for containers.
- Control groups define the amount of resources to be isolated, such as isolating a specific amount of disk space.
New Section
This section explains that Docker runs natively on Linux but can be installed on Windows and macOS by first installing Linux as a guest operating system.
Docker Installation on Non-Linux Operating Systems
- Docker relies on Linux for resource isolation techniques like name spacing and control groups.
- Operating systems like Windows and macOS do not have native support for these techniques.
- When installing Docker on non-Linux operating systems, it first installs Linux as a guest operating system.
- On top of the Linux operating system, the Docker runtime is installed along with its components.
- Communication between containers happens via the Docker Daemon to the Linux kernel and then to the hypervisor if virtualization is used.
New Section
This section addresses why virtualization is still relevant despite containerization being widely used.
Relevance of Virtualization
- Containerization platforms like Docker work on a runtime that relies on Linux for resource isolation techniques.
- A base operating system is still needed to host containers in containerization platforms.
- Virtualization is still widely used because it provides an additional layer of abstraction and allows running different operating systems simultaneously.
New Section Introduction to Virtualization
In this section, the speaker introduces the concept of virtualization and its relevance in modern computing.
Understanding Virtualization
- Virtualization allows multiple operating systems to run on a single machine, enabling resource sharing and cost savings.
- Virtualization remains relevant even with the emergence of containerization platforms, serving specific requirements.
- Physical hardware, such as bare metal servers, forms the foundation for virtualization.
- Hypervisors are installed on top of physical hardware to enable virtualization of multiple operating systems.
- Linux VMs can be created on top of hypervisors, with Docker containers running within each VM.
By leveraging virtualization and containerization together, resource isolation can be achieved effectively.
The transcript is already in English.