Chapter 6 Flashcards
is a virtualization technology used to deploy and run applications and services without the need to deploy a virtual server for each solution
Containerization
The simplified and flexible deployment architecture established by containerization can directly support… and …
Cost reduction
Business agility business drivers of cloud computing
The operating system programs used to support the execution and activve operation of apps are referred to as
runtime
The component responsible for creating and running multiple virtual servers from a physical server
hypervisor
Two types of virtualization
Type - 1(Hypervisor based) - no OS on physical hardware
Type - 2(OS based) - physical hardware has OS and may have hypervisor
is a virtualized hosting environmnt that can be optimized to provide only the resources required for its software program
container
Container image
pre-defined template that is used to create deployed containers
Container engine
referred to as containerization engine, is responsible for creating containers based on pre-defined container images
Two planes of container engine
management - tools to adminstrators to manages the environment
control - remaining functions that the engine carries out automatically
Pod
also known as a logical pod container is a special type of system container that can be used to host a single container or group of containers that have shared storage / network res, and configuration
…environment where a container is deployed
host(node / server)
Containers can be deployed on hosts without being clustered into a pod
True
Within clustering envs host servers are referred as
nodes
Common type of host clusters
Load balanced cluster - distributes workloads
High availability cluster - system availability incase of failure
Scaling cluster - supports vertical / horizontal scaling
Containers within the same host can communicate using … and containers within different hosts can communicate using …
Local host network and Overlay network
Containerization benefits
Solution optimization - customizable isolated solution with minimal footprint
Enhanced scalability - low resource consumption allows for rapid scaling
Enhanced resiliency - new instances can be configured in case of failure
Enhanced deployment speed - faster than vms
Version support
Enhanced Portability
Containerization Risks
Lack of Isolation from Host OS
Container Attack Threat(sharing of underlying OS kernel)
Increased Complexity
Increased administrative overhead
A single container can host a single software program only
False
Containers in a pod share the same IP
true
Containers in a pod communicate how
inter-process communication
Pods further provide special containerization capabilities such as
Container chains
Orchestration
Scaling
Containers in a pod have a common storage access
True
The common storage available to containers in a pod is referred to as .. and presented as..
Volume, File System
Instances of containers that are hosted are called
Replicas
Container clusters
are pools of container instances that are instantiated in advance of their actual usage
Refers to the process of managing software packages and dependencies within containerized applications
Container package management
tool that makes containerized application packaging and distribution easier
Container package manager
Container deployment file
also referred as a package, contains the deployment workflow logic
Deployment optimizer program
program that runs before the container package manager carries out the deployment workflow and assess available hosts in the cluster to determine the optimal destination for the container to be deployed
Additional factors that the deployment optimizer program considers
- hardware and software policy limitations
- affinity and anti-affinity specifications
- data locality
- inter-workload interference
In containerization, deployment optmization is referred to
scheduling
The container package manager coordinates the deployment of containers, as per the deployment workflow logic provided in the package and the host deployment instructions it receives from the deployment optimizer.
True
Container Orchestration
process of automating the deployment, scaling and management of containerized applications in a distributed computing environement
Key operations of a container orchestrator
- Deployment
- Load Balancing
- Scaling
- Health Monitoring
- Service discovery
- ” Orchestration
- Network Orchestration
- Config Management
Key components of a container orchestrator
Container Runtime
API Server
Scheduler
Controller Manager
Distributed Key-Value Store
Networking
Storage
Container Runtime
responsible for running and managing containers on each node
API Server
central interface for interacting with the orchestrator
Responsible for decideing which node in the cluster to deploy a new container to
Scheduler
Controller Manager
managing various controllers
used by the orchestrator to store configuration, service discovery info
Distributed Key-value store
a component that provide necessary network infrastructure(routing and load balancing)
Networking
component that manages the persistent storage needs of containers, including providing access to shared storage resources and ensuring data integrity
storage
Basic steps in a container orchestrator
- Create image
- Push image to container registry
- Define the application deployment(config)
- Deploy the application
- Monitor and manage
- Manage multiple apps
…central remote repository of container images
Container registry
Container Package manager vs Orchestrator
Function - CPM is responsible for managing images and dependencies, while Orch is responsible for automating deployment, scaling and management
Scope - CPM on managing images, Orch manage containerized apps
Level of abstraction - CPM at lower level of abstrraction than Orch
Toolset - CPM provide limited set of tools on managing images.
A container network provides capabilities in support of
Availability
Scalability
Flexibility
The scope of a container network is usually equal to the scope
of the solution
Containers require separate network addresses if they participate in different networks
True
Network addresses are assigned by
the container engine or administrator
Rich containers
Containers that are feature-rich
Feature-rich container features
- Limiting resource consumption
- Logs
- Restart criteria
- Storage management
- Proxy features
Further container chx
- Numerous supporting programs can be hosted in a container
- Infrastructure needs can be limited
- Visibility of external resources can be limited
- App and container lifecycle are in sync
Two primary types of container images
Base
Customized
Base container images
act as templates for customized container images. referred to as partial container images
Customized container images
are created by the container engine, which then uses them to create actual, deployed containers.
Key characteristic of container images
Immutability
Operating system abstraction
base container image provides a subset of functions of the underlying os
the OS kernel abstracted by container images
False
How do containers interact with the kernel of the OS
through container engines
Container build file
human-editable, machine-processable configuration file that specifies what belongs in (or what is abstracted by) a customized container image
The build file identifies
- Base container image for the customized image
- Additional OS resources to be abstracted or added
- Container networks that the container needs to participate in
The containerization platform uses … file system as the basis of container image layering
union
A software program that will be hosted by the container can be seen as an image layer
true
How customized container images are created
The administrator authors a build file for the container
The administrator provides the build file to the container engine
The container engine retrieves the required base container image from the image registry
The container engine then uses the base container image and the information from the build file to create a new customized container image from which it then generates and deploys
Where is customized container image usually stored
in the container engine internal memory or storage for efficient access
Types of Multi-container types
Sidecar container
Adapter container
Ambassador container
Sidecar container
a secondary containerized app component that is added to abstract utility logic-related processing. can be deployed as a separate container
Adapter container
a secondary containerized app component to take care of data conversion logic
Ambassador container
a secondary containerized app component to take care of communication processing logic
