MASTERING KUBERNETES : master the art of container management by using the power of kubernetes, ... 2nd edition

Kubernetes is an open source system that is used to automate the deployment, scaling, and management of containerized applications. If you are running more containers or want automated management of your containers, you need Kubernetes at your disposal. To put things into perspective, Mastering Kubernetes walks you through the advanced management of Kubernetes clusters. To start with, you will learn the fundamentals of both Kubernetes architecture and Kubernetes design in detail. You will discover how to run complex stateful microservices on Kubernetes including advanced features such as horizontal pod autoscaling, rolling updates, resource quotas, and persistent storage backend. Using real-world use cases, you will explore the options for network configuration, and understand how to set up, operate, and troubleshoot various Kubernetes networking plugins. In addition to this, you will get to grips with custom resource development and utilization in automation and maintenance workflows. To scale up your knowledge of Kubernetes, you will encounter some additional concepts based on the Kubernetes 1.10 release, such as Promethus, Role-based access control, API aggregation, and more. By the end of this book, you'll know everything you need to graduate from intermediate to advanced level of understanding Kubernetes. Cover......Page 1 Title Page......Page 2 Copyright and Credits......Page 3 Packt Upsell......Page 4 Contributors......Page 5 Table of Contents......Page 7 Preface......Page 21 Chapter 1: Understanding Kubernetes Architecture......Page 26 What Kubernetes is not......Page 27 The benefits of containers......Page 28 Cattle versus pets......Page 29 Kubernetes concepts......Page 30 Cluster......Page 31 Pod......Page 32 Annotations......Page 33 Replication controllers and replica sets......Page 34 Volume......Page 35 Names......Page 36 Distributed systems design patterns......Page 37 Adapter pattern......Page 38 The Kubernetes APIs......Page 39 Workloads API......Page 40 Config and storage......Page 41 Master components......Page 42 Cloud controller manager......Page 43 Proxy......Page 45 Kubernetes runtimes......Page 46 The Container Runtime Interface (CRI)......Page 47 Docker......Page 49 App container......Page 50 Is rkt ready for use in production?......Page 51 Continuous integration and deployment......Page 52 What is a CI/CD pipeline?......Page 53 Summary......Page 54 Chapter 2: Creating Kubernetes Clusters......Page 55 On Windows......Page 56 On macOS......Page 57 Creating the cluster......Page 58 Troubleshooting......Page 59 Checking out the cluster......Page 60 Examining the cluster with the dashboard......Page 62 Getting ready......Page 64 Installing the required software......Page 65 The host file......Page 66 The playbook.yml file......Page 67 Initializing the master......Page 68 Setting up the pod network......Page 70 Adding the worker nodes......Page 71 The cloud-provider interface......Page 72 Amazon Web Services (AWS)......Page 73 Amazon Elastic Container Service for Kubernetes (EKS)......Page 74 Azure......Page 75 Use cases for bare metal......Page 76 The process......Page 77 Summary......Page 78 Chapter 3: Monitoring, Logging, and Troubleshooting......Page 79 cAdvisor......Page 80 Installing Heapster......Page 81 InfluxDB backend......Page 82 CPU......Page 83 Memory......Page 84 Uptime......Page 85 Grafana visualization......Page 86 Performance analysis with the dashboard......Page 87 Cluster......Page 88 Workloads......Page 92 Discovery and load balancing......Page 94 Adding central logging......Page 95 Fluentd......Page 96 Detecting node problems......Page 97 Problem daemons......Page 98 Hardware failure......Page 99 Quotas, shares, and limits......Page 100 Bad configuration......Page 102 Using Prometheus......Page 103 Installing Prometheus with kube-prometheus......Page 104 Monitoring your cluster with Prometheus......Page 105 Summary......Page 108 High-availability concepts......Page 109 Hot swapping......Page 110 Idempotency......Page 111 Creating highly available clusters......Page 112 Clustering etcd......Page 114 Installing the etcd operator......Page 115 Verifying the etcd cluster......Page 118 Running leader election with Kubernetes......Page 119 Leader election for your application......Page 120 Making your staging environment highly available......Page 122 Testing high availability......Page 123 Live cluster upgrades......Page 124 Rolling upgrades......Page 125 Complex deployments......Page 126 Managing data-contract changes......Page 127 Deprecating APIs......Page 128 Availability requirements......Page 129 Maintenance windows......Page 130 Quick recovery......Page 131 Zero-downtime......Page 132 Summary......Page 134 Chapter 5: Configuring Kubernetes Security, Limits, and Accounts......Page 136 Node challenges......Page 137 Image challenges......Page 140 Pod and container challenges......Page 141 Organizational, cultural, and process challenges......Page 142 Understanding service accounts in Kubernetes......Page 143 Accessing the API server......Page 145 Authenticating users......Page 146 Authorizing requests......Page 148 Using admission control plugins......Page 149 Securing pods......Page 151 ImagePullSecrets......Page 152 Specifying a security context......Page 153 Securing a pod with AppArmor......Page 154 Writing AppArmor profiles......Page 155 Pod security policies......Page 156 Authorizing pod security policies through RBAC......Page 157 Choosing a supported networking solution......Page 158 Defining a network policy......Page 159 Cross-namespace policies......Page 160 Configuring encryption at Rest......Page 161 Creating secrets......Page 162 Using secrets in a container......Page 163 Running a multiuser cluster......Page 164 Using namespaces for safe multitenancy......Page 165 Avoiding namespace pitfalls......Page 166 Summary......Page 167 Designing the Hue platform......Page 168 Defining the scope of Hue......Page 169 Hue components......Page 170 Hue microservices......Page 172 Automatic workflows......Page 173 Using Kubectl effectively......Page 174 Understanding Kubectl resource configuration files......Page 175 Creating pods......Page 177 Deploying long-running processes with deployments......Page 179 Updating a deployment......Page 180 Deploying an internal service......Page 181 Creating the hue-reminders service......Page 183 Ingress......Page 184 Using namespace to limit access......Page 186 Launching jobs......Page 188 Running jobs in parallel......Page 189 Scheduling cron jobs......Page 190 Inside-the-cluster-network components......Page 192 Using liveness probes to ensure your containers are alive......Page 193 Using readiness probes to manage dependencies......Page 194 Employing Init Containers for orderly pod bring-up......Page 195 Sharing with DaemonSet pods......Page 196 Advancing science with Hue......Page 197 Summary......Page 198 Persistent volumes walk-through......Page 199 Using emptyDir for intra-pod communication......Page 200 Using HostPath for intra-node communication......Page 201 Using local volumes for durable node storage......Page 203 Provisioning persistent volumes......Page 204 Creating persistent volumes......Page 205 Access modes......Page 206 Making persistent volume claims......Page 207 Mounting claims as volumes......Page 209 Raw block volumes......Page 210 Storage classes......Page 211 Demonstrating persistent volume storage end to end......Page 213 Public storage volume types – GCE, AWS, and Azure......Page 216 AWS Elastic Block Store (EBS)......Page 217 AWS Elastic File System......Page 218 GCE persistent disk......Page 219 Azure file storage......Page 220 Using GlusterFS......Page 222 Creating endpoints......Page 223 Creating pods......Page 224 Connecting to Ceph using RBD......Page 225 Connecting to Ceph using CephFS......Page 227 Flocker as a clustered container data volume manager......Page 228 Integrating enterprise storage into Kubernetes......Page 229 Projecting volumes......Page 230 Using out-of-tree volume plugins with FlexVolume......Page 231 The Container Storage Interface......Page 232 Summary......Page 233 Stateful versus stateless applications in Kubernetes......Page 234 Why manage state outside of Kubernetes?......Page 235 Accessing external data stores via environment variables......Page 236 Consuming a ConfigMap as an environment variable......Page 237 Utilizing StatefulSet......Page 239 The components of StatefulSet......Page 240 Running a Cassandra cluster in Kubernetes......Page 241 Quick introduction to Cassandra......Page 242 The Cassandra Docker image......Page 243 Exploring the run.sh script......Page 244 Digging into the Cassandra configuration......Page 249 The custom seed provider......Page 250 Creating a Cassandra headless service......Page 251 Dissecting the stateful set configuration file......Page 252 Dissecting the replication controller configuration file......Page 256 Assigning pods to nodes......Page 259 Using DaemonSet to distribute Cassandra......Page 260 Summary......Page 261 Horizontal pod autoscaling......Page 262 Declaring horizontal pod autoscaler......Page 263 Custom metrics......Page 265 Autoscaling with kubectl......Page 266 Performing rolling updates with autoscaling......Page 269 Handling scarce resources with limits and quotas......Page 270 Resource quota types......Page 271 Storage resource quota......Page 272 Object count quota......Page 273 Quota scopes......Page 274 Creating quotas......Page 275 Using limit ranges for default compute quotas......Page 279 Choosing your node types......Page 280 Trading off cost and response time......Page 281 Benefiting from elastic cloud resources......Page 282 Mind your cloud quotas......Page 283 Considering Hyper.sh (and AWS Fargate)......Page 284 Improving the performance and scalability of Kubernetes......Page 285 The pod life cycle event generator......Page 286 etcd3......Page 287 Measuring the performance and scalability of Kubernetes......Page 288 Measuring API responsiveness......Page 289 Measuring end-to-end pod startup time......Page 292 Testing Kubernetes at scale......Page 293 Comparing a Kubemark cluster to a real-world cluster......Page 294 Summary......Page 295 Chapter 10: Advanced Kubernetes Networking......Page 296 Inter-pod communication (pod to pod)......Page 297 External access......Page 298 Kubernetes networking versus Docker networking......Page 299 Lookup and discovery......Page 300 Services and endpoints......Page 301 Loosely coupled connectivity with data stores......Page 302 Network namespaces......Page 303 Maximum transmission unit......Page 304 Requirements......Page 305 Container Networking Interface (CNI)......Page 306 CNI plugin......Page 307 Contiv......Page 310 Open vSwitch......Page 311 Canal......Page 313 Flannel......Page 314 Romana......Page 316 Weave net......Page 317 Configuring network policies......Page 318 Implementing network policies......Page 319 External load balancer......Page 320 Configuring an external load balancer......Page 321 Finding the load balancer IP addresses......Page 322 Specifying original client IP address preservation......Page 323 Service load balancer......Page 324 Ingress......Page 325 HAProxy......Page 326 Running HAProxy Inside the Kubernetes cluster......Page 327 Træfic......Page 328 First look at the loopback plugin......Page 329 Building on the CNI plugin skeleton......Page 331 Reviewing the bridge plugin......Page 332 Summary......Page 334 Understanding cluster federation......Page 335 Important use cases for cluster federation......Page 336 Sensitive workloads......Page 337 The federation control plane......Page 338 Federation API server......Page 339 Federated ConfigMap......Page 340 Deleting a federated ConfigMap......Page 341 Federated Events......Page 342 Federated Horizontal Pod Scaling......Page 343 Federated ingress......Page 344 Handling failures with federated ingress......Page 345 Federated ReplicaSet......Page 346 The hard parts......Page 347 Strictly-coupled......Page 348 Uniformly-spread......Page 349 Federated auto-scaling......Page 350 Setting up cluster federation from the ground up......Page 351 Using the official Hyperkube image......Page 352 Registering Kubernetes clusters with the federation......Page 353 Updating KubeDNS......Page 354 Getting Kubefed......Page 355 Deploying a federation control plane......Page 356 Naming rules and customization......Page 357 Shutting down the federation......Page 358 Load balancing across multiple clusters......Page 359 Failing over across multiple clusters......Page 360 Federated migration......Page 361 Creating a federated service......Page 362 Adding backend pods......Page 363 Verifying public DNS records......Page 364 Discovering a federated service......Page 365 DNS expansion......Page 366 Handling failures of backend pods and whole clusters......Page 367 Federated service is created successfully but no service is created in the underlying clusters......Page 368 Summary......Page 369 Working with the Kubernetes API......Page 370 Exploring the Kubernetes API directly......Page 371 Using Postman to explore the Kubernetes API......Page 373 Filtering the output with httpie and jq......Page 374 Creating a pod via the Kubernetes API......Page 375 Accessing the Kubernetes API via the Python client......Page 376 Dissecting the CoreV1API group......Page 377 Listing objects......Page 378 Creating objects......Page 379 Invoking Kubectl programmatically......Page 380 Using Python subprocess to run Kubectl......Page 381 Extending the Kubernetes API......Page 382 Understanding the structure of a custom resource......Page 383 Developing custom resource definitions......Page 384 Integrating custom resources......Page 385 Finalizing custom resources......Page 386 Understanding API server aggregation......Page 387 Utilizing the service catalog......Page 388 Writing a custom scheduler plugin......Page 389 The scheduler......Page 390 Configuring the scheduler......Page 391 Packaging the scheduler......Page 392 Deploying the custom scheduler......Page 393 Assigning pods to the custom scheduler......Page 394 Employing access control webhooks......Page 395 Using an authentication webhook......Page 396 Using an authorization webhook......Page 398 Using an admission control webhook......Page 399 Providing custom metrics for horizontal pod autoscaling......Page 400 Extending Kubernetes with custom storage......Page 401 Benefitting from CSI......Page 402 Summary......Page 403 Understanding Helm......Page 404 Helm components......Page 405 Installing Helm......Page 406 Installing Tiller in-cluster......Page 407 Using Alternative Storage Backend......Page 408 Finding charts......Page 409 Installing packages......Page 411 Customizing a chart......Page 413 Upgrading and rolling back a release......Page 415 Deleting a release......Page 416 Working with repositories......Page 417 Taking advantage of starter packs......Page 418 The Chart.yaml file......Page 419 Deprecating charts......Page 420 Managing dependencies with requirements.yaml......Page 421 Using special fields in requirements.yaml......Page 422 Writing template files......Page 424 Using pipelines and functions......Page 425 Feeding values from a file......Page 426 Scope, dependencies, and values......Page 427 Summary......Page 428 The road ahead......Page 429 Kubernetes releases and milestones......Page 430 The value of bundling......Page 431 Cloud platforms......Page 432 Azure......Page 433 GitHub......Page 434 Mindshare......Page 435 OpenStack......Page 436 Education and training......Page 437 Modularization and out-of-tree plugins......Page 438 Service meshes......Page 439 Summary......Page 440 Other Books You May Enjoy......Page 441 Index......Page 444 Exploit design, deployment, and management of large-scale containersKey FeaturesExplore the latest features available in Kubernetes 1.10Ensure that your clusters are always available, scalable, and up to dateMaster the skills of designing and deploying large clusters on various cloud platformsBook DescriptionKubernetes is an open source system that is used to automate the deployment, scaling, and management of containerized applications. If you are running more containers or want automated management of your containers, you need Kubernetes at your disposal. To put things into perspective, Mastering Kubernetes walks you through the advanced management of Kubernetes clusters. To start with, you will learn the fundamentals of both Kubernetes architecture and Kubernetes design in detail. You will discover how to run complex stateful microservices on Kubernetes including advanced features such as horizontal pod autoscaling, rolling updates, resource quotas, and persistent storage backend. Using real-world use cases, you will explore the options for network configuration, and understand how to set up, operate, and troubleshoot various Kubernetes networking plugins. In addition to this, you will get to grips with custom resource development and utilization in automation and maintenance workflows. To scale up your knowledge of Kubernetes, you will encounter some additional concepts based on the Kubernetes 1.10 release, such as Promethus, Role-based access control, API aggregation, and more. By the end of this book, you'll know everything you need to graduate from intermediate to advanced level of understanding Kubernetes. What you will learnArchitect a robust Kubernetes cluster for long-time operationDiscover the advantages of running Kubernetes on GCE, AWS, Azure, and bare metalUnderstand the identity model of Kubernetes, along with the options for cluster federationMonitor and troubleshoot Kubernetes clusters and run a highly available KubernetesCreate and configure custom Kubernetes resources and use third-party resources in your automation workflowsEnjoy the art of running complex stateful applications in your container environmentDeliver applications as standard packagesWho this book is forMastering Kubernetes is for you if you are a system administrator or a developer who has an intermediate understanding of Kubernetes and wish to master its advanced features. Basic knowledge of networking would also be helpful. In all, this advanced-level book provides a smooth pathway to mastering Kubernetes. Cover -- Title Page -- Copyright and Credits -- Packt Upsell -- Contributors -- Table of Contents -- Preface -- Chapter 1: Understanding Kubernetes Architecture -- What is Kubernetes? -- What Kubernetes is not -- Understanding container orchestration -- Physical machines, virtual machines, and containers -- The benefits of containers -- Containers in the cloud -- Cattle versus pets -- Kubernetes concepts -- Cluster -- Node -- Master -- Pod -- Label -- Annotations -- Label selectors -- Replication controllers and replica sets -- Services -- Volume -- StatefulSet -- Secrets -- Names -- Namespaces -- Diving into Kubernetes architecture in-depth -- Distributed systems design patterns -- Sidecar pattern -- Ambassador pattern -- Adapter pattern -- Multinode patterns -- The Kubernetes APIs -- Resource categories -- Workloads API -- Discovery and load balancing -- Config and storage -- Metadata -- Cluster -- Kubernetes components -- Master components -- API server -- Etcd -- Kube controller manager -- Cloud controller manager -- Kube-scheduler -- DNS -- Node components -- Proxy -- Kubelet -- Kubernetes runtimes -- The Container Runtime Interface (CRI) -- Docker -- Rkt -- App container -- Cri-O -- Rktnetes -- Is rkt ready for use in production? -- Hyper containers -- Stackube -- Continuous integration and deployment -- What is a CI/CD pipeline? -- Designing a CI/CD pipeline for Kubernetes -- Summary -- Chapter 2: Creating Kubernetes Clusters -- A quick single-node cluster with Minikube -- Getting ready -- On Windows -- On macOS -- Creating the cluster -- Troubleshooting -- Checking out the cluster -- Doing work -- Examining the cluster with the dashboard -- Creating a multinode cluster using kubeadm -- Setting expectations -- Getting ready -- Preparing a cluster of vagrant VMs -- Installing the required software -- The host file -- The vars.yml file