What is Kubernetes, its basics and components?
Overview of Kubernetes Components. Kubernetes is an open-source platform for managing containerized workloads and services. Some of its capabilities include: Service discovery and load balancing: It can expose a container using the DNS name or using their own IP address and if the traffic to a container is high, Kubernetes is able to load ...
What does Kubernetes have to do with microservices?
Some high-level advantages Kubernetes offers for microservice architecture are:
- Self-healing. When a container fails or is unhealthy, Kubernetes replaces it automatically to maintain a desired state configuration and the overall health of the application.
- Declarative configuration management and version control. ...
- Multi-cloud and hybrid cloud. ...
- Service exposure and load balancing. ...
- Secrets management. ...
- Scalability. ...
- Zero downtime. ...
What are some alternatives to Kubernetes?
What is Kubernetes?
- Basics of orchestration. While all the tools for Orchestration are classified in the terms of ease of use, the features offered and supported.
- List of Kubernetes Alternatives. Swarm and Docker Engine both make it possible to deploy the containers in Swarm mode. ...
- Recommended Articles. This has been a guide on Kubernetes Alternatives. ...
What's the deal with the name "Kubernetes"?
Kubernetes is a portable, extensible, open-source platform for managing containerized workloads and services, that facilitates both declarative configuration and automation. It has a large, rapidly growing ecosystem. Kubernetes services, support, and tools are widely available. The name Kubernetes originates from Greek, meaning helmsman or pilot.
Why we use Istio in Kubernetes?
Istio makes traffic management transparent to the application, moving this functionality out of the application and into the platform layer as a cloud native infrastructure. Istio complements Kubernetes, by enhancing its traffic management, observability and security for cloud native applications.
What is difference between Istio and Kubernetes?
Istio's control plane provides an abstraction layer over the underlying cluster management platform, such as Kubernetes, Mesos, etc. On the other hand, Kubernetes is detailed as "Manage a cluster of Linux containers as a single system to accelerate Dev and simplify Ops".
What does Istio stand for?
Final note: Istio is not an acronym, but if it stood for something, maybe it would be, “I Secure, Then I Observe,” or “I'm Sexy To Infrastructure Operators.” If you can come up with something better, please post it to twitter.com/tetrateio.
Is Istio for Kubernetes only?
Istio's control plane runs on Kubernetes, and you can add applications deployed in that cluster to your mesh, extend the mesh to other clusters, or even connect VMs or other endpoints running outside of Kubernetes.
Is Istio a load balancer?
By default, Istio uses a round-robin load balancing policy, where each service instance in the instance pool gets a request in turn. Istio also supports the following models, which you can specify in destination rules for requests to a particular service or service subset.
Does Istio use nginx?
Adding the Ingress and Virtual Service for weighted routing Use a Separate K8s Ingress resource for each route that you want handled according to a specific Istio Virtual Service. In that Ingress you will use the nginx.ingress.kubernetes.io/upstream-vhost annotation to specify the cluster.
Is Istio an API Gateway?
The Istio ingress is an API gateway implementation which accepts client calls and routes them to the application services inside the mesh.
Who is using Istio?
Istio has a large community of providers and users. The Istio SIG of Cloud Native Community has held eight Istio Big Talk, with Baidu, Tencent, NetEase, Xiaohongshu, and Xiaodian Technology sharing their Istio practices.
Why do we need service mesh?
Some advantages of a service mesh are as follows: Simplifies communication between services in both microservices and containers. Easier to diagnose communication errors, because they would occur on their own infrastructure layer. Supports security features such as encryption, authentication and authorization.
What is the difference between Istio and ingress?
Along with support for Kubernetes Ingress , Istio offers another configuration model, Istio Gateway . A Gateway provides more extensive customization and flexibility than Ingress , and allows Istio features such as monitoring and route rules to be applied to traffic entering the cluster.
Is Istio an ingress controller?
Configuring ingress using an Ingress resource The kubernetes.io/ingress.class annotation is required to tell the Istio gateway controller that it should handle this Ingress , otherwise it will be ignored.
Is Istio a proxy?
Istio uses an extended version of the Envoy proxy. Envoy is a high-performance proxy developed in C++ to mediate all inbound and outbound traffic for all services in the service mesh. Envoy proxies are the only Istio components that interact with data plane traffic.
What is Istio and why it is used?
Istio defined Istio is an open source service mesh that helps organizations run distributed, microservices-based apps anywhere. Why use Istio? Istio enables organizations to secure, connect, and monitor microservices, so they can modernize their enterprise apps more swiftly and securely.
What is the difference between Istio and ingress?
Along with support for Kubernetes Ingress , Istio offers another configuration model, Istio Gateway . A Gateway provides more extensive customization and flexibility than Ingress , and allows Istio features such as monitoring and route rules to be applied to traffic entering the cluster.
Is Kubernetes a service mesh?
Service mesh in Kubernetes enables services to detect each other and communicate. It also uses intelligent routing to control API calls and the flow of traffic between endpoints and services. This further enables canaries or rolling upgrades, blue/green, and other advanced deployment strategies.
Does Istio replace Kube proxy?
Istio sidecar proxy works just like Kube-proxy userspace mode. They both work in userspace to proxy the client request and load balance among multiple back-end Pods. The difference is that Kube-proxy only works on OSI layer 4, while Istio sidecar proxy can also handle OSI layer 7 packages.
How to configure Kubernetes?
The primary method to set configuration with Kubernetes is the kubectl command, commonly "kubectl -f <filename>", where the file is a YAML file. Istio users can either run new and different types of YAML files with kubectl or use the new, optional, ioctl command.
What is Istio?
Istio is a configurable, open source service-mesh layer that connects, monitors, and secures the containers in a Kubernetes cluster. At this writing, Istio works natively with Kubernetes only, but its open source nature makes it possible for anyone to write extensions enabling Istio to run on any cluster software. Today, we'll focus on using Istio with Kubernetes, its most popular use case.
What is Kubernetes core?
Kubernetes is a container orchestration tool, and one core unit of Kubernetes is a node. A node consists of one or more containers, along with file systems or other components. A microservices architecture might have a dozen different nodes, each representing different microservices. Kubernetes manages availability and resource consumption of nodes, adding pods as demand increases with the pod autoscaler. Istio injects additional containers into the pod to add security, management, and monitoring.
What is Red Hat OpenShift?
Deploy highly available, fully managed Kubernetes clusters with Red Hat OpenShift on IBM Cloud, a managed OpenShift service that leverages the enterprise scale and security of IBM Cloud to automate updates, scaling and provisioning. Red Hat OpenShift on IBM Cloud includes an OpenShift Service Mesh capability that uses the Istio control plane to control connections between containerized services, enforce policies, observe behaviors and more.
What is the name of the layer that is on top of Kubernetes?
Istio and Kubernetes. As mentioned earlier, Istio layers on top of Kubernetes, adding containers that are essentially invisible to the programmer and administrator. Called "sidecar" containers, these act as a "person in the middle," directing traffic and monitoring the interactions between components.
What is Istio monitoring?
With Istio, you can easily monitor the health of your applications running with Kubernetes. Istio's instrumentation can manage and visualize the health of applications, providing more insight than just the general monitoring of cluster and nodes that Kubernetes provides.
What is IBM Cloud Kubernetes Service?
Gain improved control of your containerized applications with IBM Cloud Kubernetes Service, which provides seamless installation of Istio, automatic updates and lifecycle management of control plane components, and integration with platform logging and monitoring tools.
How to learn Istio?
If you already have experience with Kubernetes, a good way to learn Istio is to take a Kubernetes cluster— not one already in production!—and install Istio on it by way of a Helm chart. Then you can deploy a sample application that demonstrates common Istio features like intelligent traffic management and telemetry. This should give you some ground-level experience with Istio before deploying it for service-mesh duty on your application cluster.
How does Istio work?
Istio works as a service mesh by providing two basic pieces of architecture for your cluster, a data plane and a control plane.
What is gallery in Istio?
Gallery takes user-specified configurations for Istio and converts them into valid configurations for the other control plane components . This is another element that allows Istio to use different orchestration systems transparently.
What is Istio pilot?
Istio Pilot takes the rules for traffic behavior provided by the control plane, and converts them into configurations applied by Envoy, based on how such things are managed locally. Pilot will allow Istio to work with different orchestration systems besides Kubernetes, but behave consistently between them.
What is the benefit of Istio?
The first and most valuable benefit Istio provides is abstraction—a way to deal with the complexities of a service mesh at arm’s length. You can make any changes to the mesh programmatically by commanding Istio.
What is the control plane in Istio?
The control plane, Istio’s core, manages and secures the data plane. It configures both the Envoy proxies and the Mixers that enforce the network policies for the services, such as who gets to talk to whom and when. The control plane also provides a programmatic abstraction layer for the data plane and all of its behaviors.
Is Istio a breaker?
Istio provides a circuit breaker pattern as part of its standard library of policy enforcements. Finally, while Istio works most directly and deeply with Kubernetes, it is designed to be platform independent. Istio plugs into the same open standards that Kubernetes itself relies on.
Why Is There an Istio?
To explain what Istio is, it’s also important to understand the context in which Istio came into being — i.e., why is there an Istio?
The Basics of Istio
The following diagram shows the service model in Istio, which supports both workloads and virtual machines in Kubernetes.
Summary
Service Mesh is the cloud native equivalent of TCP/IP, addressing application network communication, security and visibility issues.
What happened here?
Images 1–5 display the same example Kubernetes application with nginx and python pods. We have seen how a request happens using default Kubernetes services and then using Istio.
Why all this, why using Istio?
If nothing has changed when using Istio (the nginx pods can still connect to python pods just as before) why use Istio then in the first place?
Does Istio replace Kubernetes services?
No. One question I asked myself when I began with Istio was if it would replace existing Kubernetes services. The answer is no. Istio uses existing Kubernetes services to get all their endpoints/pod IP addresses.
What happens if the Istio Control Plane is down?
Because all istio-proxy sidecars are already programmed, the Istio Control Plane could go down and traffic works as before. But config updates or new pods created wouldn’t be applied.
What is Kubernetes service?
Image 2 shows the same example as in image 1, just in more detail. Services in Kubernetes are implemented by the kube-proxy component which runs on every node. This component creates iptables rules which redirect requests to pods. Hence services are nothing else than iptables rules. (There are other proxy modes available which don’t use iptables, but the procedure is the same.)
How many nodes are there in Kubernetes cluster?
Image 1 shows a Kubernetes cluster with two nodes and 4 pods with one container each. There is service service-nginx which points to the nginx pods and service service-python which points to the python pods. The red line shows a request made from the nginx container in pod1-nginx to the service-python service, which redirects the request to pod2-python.
What is Istio service mesh?
Istio is a Service Mesh which allows for more detailed, complex and observable communication between pods and services in the cluster.
Why use Istio or any service mesh for that matter?
If you are a developer or architect looking to create a network of deployed services with built-in traffic control features, service-to-service authentication and monitoring, all without having to make changes to your service code and you don’t mind running them on Kubernetes, then Istio is a good solution, even though it is not easy to install and requires a fair amount of knowledge of both, its own and Kubernetes’ internals to troubleshoot.
What is a service mesh?
A service mesh is not a “mesh of services.” It is a mesh of Layer 7 proxies that microservices can use to completely abstract the network away. Service meshes are designed to solve the many challenges developers face when talking to remote endpoints.
What is Istio mesh?
Istio is an open source service mesh designed to make it easier to connect, manage and secure traffic between, and obtain telemetry about microservices running in containers. Istio is a collaboration between IBM, Google and Lyft. It was originally announced in May 2017, with a 1.0 version released in July of 2018.
What is Istio traffic management?
Traffic management: Istio separates traffic management from infrastructure scaling (which is handled by Kubernetes). This separation allows for features that can live outside the application code, like dynamic request routing for A/B testing, gradual rollouts, canary releases, retries, circuit breakers and fault injection.
What are the features of Istio?
Why use Istio or any service mesh for that matter? 1 Traffic control features including routing rules, retries, failovers, and fault injection 2 Policy enforcement including access controls, rate limits and quotas 3 Built-in metrics, logs, and traces for all traffic within a cluster 4 Secure service-to-service communication 5 Layer 7 load balancing
What is the Istio component?
How this communication is managed needs to be configured, of course. Istio’s component that is responsible for configuring the data plane is called Pilot. Apart from defining basic proxy behaviors, it also allows you to specify routing rules between proxies as well as failure recovery features.
Why are service meshes not widely used?
This is undoubtedly due in part to their relative novelty and the fact that the general space is still evolving. However, service meshes are also not without criticisms.
What is the key to understanding Istio?
The key to understanding Istio and the Istio architecture is to know about both Envoy and Kubernetes. It’s not a question of Istio versus Envoy or Istio versus Kubernetes—they often work together to make a microservices-based containerized environment operate smoothly.
What is Istio used for?
Istio allows organizations to deliver distributed applications at scale. It simplifies service-to-service network operations like traffic management, authorization, and encryption, as well as auditing and observability. Here are some of the most common use cases that deliver the benefits of Istio:
What is Istio platform?
Istio is platform-independent and designed to run in a variety of environments: 1 Cloud 2 On-premises 3 Kubernetes 4 Mesos
Installing Istio
Choose one of the following installation options, depending on your intended use:
Downloading the release
Istio is installed in its own istio-system namespace and can manage services from all other namespaces.
What is Istio?
Istio is an open source service mesh that layers transparently onto existing distributed applications. Istio’s powerful features provide a uniform and more efficient way to secure, connect, and monitor services. Istio is the path to load balancing, service-to-service authentication, and monitoring – with few or no service code changes. Its powerful control plane brings vital features, including:
What is Istio control plane?
Istio’s control plane runs on Kubernetes, and you can add applications deployed in that cluster to your mesh, extend the mesh to other clusters, or even connect VMs or other endpoints running outside of Kubernetes.
What is Istio telemetry?
As services grow in complexity, it becomes challenging to understand behavior and performance. Istio generates detailed telemetry for all communications within a service mesh. This telemetry provides observability of service behavior, empowering operators to troubleshoot, maintain, and optimize their applications. Even better, you get almost all of this instrumentation without requiring application changes. Through Istio, operators gain a thorough understanding of how monitored services are interacting.
What is Istio traffic routing?
Routing traffic, both within a single cluster and across clusters, affects performance and enables better deployment strategy. Istio’s traffic routing rules let you easily control the flow of traffic and API calls between services. Istio simplifies configuration of service-level properties like circuit breakers, timeouts, and retries, and makes it easy to set up important tasks like A/B testing, canary deployments, and staged rollouts with percentage-based traffic splits.