122 lines
4.8 KiB
Markdown
122 lines
4.8 KiB
Markdown
---
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title: Using Helm and Pulumi to define cloud native infrastructure
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h1: "Using Helm and Pulumi to define cloud native infrastructure as code"
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authors: ["alex-clemmer"]
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tags: ["Kubernetes","Azure"]
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date: "2018-10-31"
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meta_desc: "In this post, we run a Pulumi program that manages both Azure and Kubernetes resources and dependencies, and deploys a Node.js Helm chart."
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meta_image: "helm-pulumi-deploy.png"
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---
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The Helm community is one of the brightest spots in the infrastructure
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ecosystem: collectively, it has accumulated person-decades of
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operational expertise to produce Kubernetes manifests that "just work."
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But for many users, it is not feasible to run *everything* in
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Kubernetes, and the community is just starting to develop answers to
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questions like: what happens when a Helm Chart needs to interface with,
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for example, a managed database like AWS RDS or Azure CosmosDB?
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Pulumi is a cloud native development platform designed to be able to
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express any cloud native infrastructure as code in a natural,
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intentional manner using familiar languages. The most natural way to solve
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this challenge would be to stand up an instance of AWS RDS, populate a
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Kubernetes Secret with the connection details, and then simply let my
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application use these newly available resources. Pulumi gives users the
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primitives they need in order to achieve tasks like this most
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effectively.
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<!--more-->
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## How to connect a Kubernetes app with CosmosDB
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In the following Pulumi program, we can manage both Azure and Kubernetes
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resources, including the interconnected dependencies between the two.
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Specifically, we:
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- Create an AKS cluster,
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- Create a MongoDB-flavored instance of Azure's CosmosDB,
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- Create a Kubernetes Secret from the connection string exported by
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CosmosDB
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- Deploy a Node.js Helm Chart that references it.
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If you have the Azure command line, try [running the example](https://github.com/pulumi/examples/tree/master/classic-azure-ts-aks-mean)
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with `pulumi up`!
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{{< highlight javascript >}}
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import * as k8s from "@pulumi/kubernetes";
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import * as azure from "@pulumi/azure";
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import * as mongoHelpers from "./mongoHelpers";
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import * as config from "./config";
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// Create an AKS cluster.
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import { k8sCluster, k8sProvider } from "./cluster";
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// Create a MongoDB-flavored instance of CosmosDB.
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const cosmosdb = new azure.cosmosdb.Account("cosmosDb", {
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kind: "MongoDB",
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resourceGroupName: config.resourceGroup.name,
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location: config.location,
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consistencyPolicy: {
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consistencyLevel: "BoundedStaleness",
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maxIntervalInSeconds: 10,
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maxStalenessPrefix: 200
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},
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offerType: "Standard",
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enableAutomaticFailover: true,
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geoLocations: [
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{ location: config.location, failoverPriority: 0 },
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{ location: config.failoverLocation, failoverPriority: 1 }
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]);
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// Create secret from MongoDB connection string.
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const mongoConnStrings = new k8s.core.v1.Secret(
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"mongo-secrets",
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{ data: mongoHelpers.parseConnString(cosmosdb.connectionStrings) },
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{ provider: k8sProvider }
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);
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// Boot up nodejs Helm chart example using CosmosDB in place of in-cluster MongoDB.
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const node = new k8s.helm.v2.Chart(
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"node",
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{
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repo: "bitnami",
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chart: "node",
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version: "4.0.1",
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values: {
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serviceType: "LoadBalancer",
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mongodb: { install: false },
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externaldb: { ssl: true, secretName: mongoConnStrings.metadata.apply(m => m.name) }
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}
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},
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{ providers: { kubernetes: k8sProvider }, dependsOn: mongoConnStrings }
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);
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{{< /highlight >}}
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Pulumi supports deploying resources to all the major cloud vendors, as
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well as Kubernetes. Using the Pulumi programming model, it is possible
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to define and deploy apps and infrastructure with an arbitrary mix of
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resources from any combination of cloud providers. And, because Pulumi
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uses normal `$KUBECONFIG` files, it is compatible anywhere you would use
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Helm or `kubectl`.
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The Pulumi CLI provides rich insight into the progress a deployment
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makes. When you run `pulumi up`, the CLI will provide detailed
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information about the progress we're making as we try to deploy the
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Chart. To get a sense of what this looks like, take a look at the
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progress reported as we deploy the Wordpress Chart:
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## Toward Cloud Native Infrastructure as Code
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As cloud native architectures mature, Pulumi can reduce the complexity
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in choosing and using the available services from cloud vendors, and
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combine those choices using a single, consistent programming model. This
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can make the best use of existing tools such as Helm, and also reduce
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the friction caused by multiple deployment tools and models across
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complex architectures.
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- Find out more about our [Azure](/azure/) and
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[Kubernetes](/kubernetes/) support
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- Join the Slack community at <https://slack.pulumi.com>
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