feat: experimental blue-green deployment

Introduce the ability to specify different deployment-strategies.
Implement blue-green deployments.
Adds "experimental" meta field to joi schemas.
Introduce "Experimental feature" warning message.

docs/reference/providers/kubernetes.md

@@ -86,6 +86,19 @@ Set a default username (used for namespacing within a cluster).
 | -------- | -------- |
 | `string` | No       |
 
+### `providers[].deploymentStrategy`
+
+[providers](#providers) > deploymentStrategy
+> ⚠️ **Experimental**: this is an experimental feature and the API might change in the future.  
+
+Defines the strategy for deploying the project services.
+Default is "rolling update" and there is experimental support for "blue/green" deployment.
+The feature only supports modules of type `container`: other types will just deploy using the default strategy.
+
+| Type     | Required | Default     |
+| -------- | -------- | ----------- |
+| `string` | No       | `"rolling"` |
+
 ### `providers[].forceSsl`
 
 [providers](#providers) > forceSsl
@@ -892,6 +905,7 @@ providers:
     buildMode: local-docker
     defaultHostname:
     defaultUsername:
+    deploymentStrategy: rolling
     forceSsl: false
     imagePullSecrets:
       - name:

docs/reference/providers/local-kubernetes.md

@@ -86,6 +86,19 @@ Set a default username (used for namespacing within a cluster).
 | -------- | -------- |
 | `string` | No       |
 
+### `providers[].deploymentStrategy`
+
+[providers](#providers) > deploymentStrategy
+> ⚠️ **Experimental**: this is an experimental feature and the API might change in the future.  
+
+Defines the strategy for deploying the project services.
+Default is "rolling update" and there is experimental support for "blue/green" deployment.
+The feature only supports modules of type `container`: other types will just deploy using the default strategy.
+
+| Type     | Required | Default     |
+| -------- | -------- | ----------- |
+| `string` | No       | `"rolling"` |
+
 ### `providers[].forceSsl`
 
 [providers](#providers) > forceSsl
@@ -793,6 +806,7 @@ providers:
     buildMode: local-docker
     defaultHostname:
     defaultUsername:
+    deploymentStrategy: rolling
     forceSsl: false
     imagePullSecrets:
       - name:

examples/deployment-strategies/README.md

@@ -0,0 +1,33 @@
+# Deployment strategies example
+
+A basic demo project showing different deployment strategies.
+
+It is based on the [examples/demo-project](https://github.com/garden-io/garden/tree/master/examples/demo-project) and it's meant to show how to configure the deployment strategies.
+
+> NOTE: the "Deployment Strategies feature" is still in the experimental phase. This means there might be changes to the properties names/values or to the behaviour in the future. Please be aware of this when using the feature.
+
+
+## Usage
+
+This project doesn't require any specific set up and can be deployed (in your local cluster) in a single step with the `deploy` command:
+
+```sh
+garden deploy --env=local-blue-green
+```
+
+The first deploy on a fresh cluster will always be a normal `rolling-update` deploy. After making some changes to any of the module you will be able to see the Blue/Green strategy in action.
+
+### Example of configuration
+
+For more detailed configuration please check out the `garden.yml` file.
+
+```yaml
+kind: Project
+name: My Project
+environments:
+  # Blue-green deployment strategy on local-kubernetes.
+  - name: local-blue-green
+    providers:
+      - name: local-kubernetes
+        deploymentStrategy: blue-green
+```

examples/deployment-strategies/backend/.dockerignore

@@ -0,0 +1,4 @@
+node_modules
+Dockerfile
+garden.yml
+app.yaml

examples/deployment-strategies/backend/.gitignore

@@ -0,0 +1,27 @@
+# Compiled Object files, Static and Dynamic libs (Shared Objects)
+*.o
+*.a
+*.so
+
+# Folders
+_obj
+_test
+
+# Architecture specific extensions/prefixes
+*.[568vq]
+[568vq].out
+
+*.cgo1.go
+*.cgo2.c
+_cgo_defun.c
+_cgo_gotypes.go
+_cgo_export.*
+
+_testmain.go
+
+*.exe
+*.test
+*.prof
+
+.vscode/settings.json
+webserver/*server*

examples/deployment-strategies/backend/Dockerfile

@@ -0,0 +1,14 @@
+FROM golang:1.8.3-alpine
+MAINTAINER Aurelien PERRIER <a.perrier89@gmail.com>
+
+ENV webserver_path /go/src/github.com/perriea/webserver/
+ENV PATH $PATH:$webserver_path
+
+WORKDIR $webserver_path
+COPY webserver/ .
+
+RUN go build .
+
+ENTRYPOINT ./webserver
+
+EXPOSE 8080

examples/deployment-strategies/backend/garden.yml

@@ -0,0 +1,14 @@
+kind: Module
+name: backend
+description: Backend service container
+type: container
+services:
+  - name: backend
+    ports:
+      - name: http
+        containerPort: 8080
+        # Maps service:80 -> container:8080
+        servicePort: 80
+    ingresses:
+      - path: /hello-backend
+        port: http

examples/deployment-strategies/backend/webserver/main.go

@@ -0,0 +1,17 @@
+package main
+
+import (
+	"fmt"
+	"net/http"
+)
+
+func handler(w http.ResponseWriter, r *http.Request) {
+	fmt.Fprint(w, "Hello from Go!")
+}
+
+func main() {
+	http.HandleFunc("/hello-backend", handler)
+	fmt.Println("Server running...")
+
+	http.ListenAndServe(":8080", nil)
+}

examples/deployment-strategies/frontend/.dockerignore

@@ -0,0 +1,4 @@
+node_modules
+Dockerfile
+garden.yml
+app.yaml

examples/deployment-strategies/frontend/Dockerfile

@@ -0,0 +1,12 @@
+FROM node:9-alpine
+
+ENV PORT=8080
+EXPOSE ${PORT}
+WORKDIR /app
+
+ADD package.json /app
+RUN npm install
+
+ADD . /app
+
+CMD ["npm", "start"]

examples/deployment-strategies/frontend/app.js

@@ -0,0 +1,27 @@
+const express = require('express');
+const request = require('request-promise')
+const app = express();
+
+const backendServiceEndpoint = `http://backend/hello-backend`
+
+app.get('/hello-frontend', (req, res) => res.send('Hello from the frontend!'));
+
+app.get('/call-backend', (req, res) => {
+  // Query the backend and return the response
+  request.get(backendServiceEndpoint)
+    .then(message => {
+      message = `Backend says: '${message}'`
+      res.json({
+        message,
+      })
+    })
+    .catch(err => {
+      res.statusCode = 500
+      res.json({
+        error: err,
+        message: "Unable to reach service at " + backendServiceEndpoint,
+      })
+    });
+});
+
+module.exports = { app }

examples/deployment-strategies/frontend/garden.yml

@@ -0,0 +1,27 @@
+kind: Module
+name: frontend
+description: Frontend service container
+type: container
+services:
+  - name: frontend
+    ports:
+      - name: http
+        containerPort: 8080
+    healthCheck:
+      httpGet:
+        path: /hello-frontend
+        port: http
+    ingresses:
+      - path: /hello-frontend
+        port: http
+      - path: /call-backend
+        port: http
+    dependencies:
+      - backend
+tests:
+  - name: unit
+    args: [npm, test]
+  - name: integ
+    args: [npm, run, integ]
+    dependencies:
+      - frontend

examples/deployment-strategies/frontend/main.js

@@ -0,0 +1,3 @@
+const { app } = require('./app');
+
+app.listen(process.env.PORT, '0.0.0.0', () => console.log('Frontend service started'));

examples/deployment-strategies/frontend/package.json

@@ -0,0 +1,22 @@
+{
+  "name": "frontend",
+  "version": "1.0.0",
+  "description": "Simple Node.js docker service",
+  "main": "main.js",
+  "scripts": {
+    "start": "node main.js",
+    "test": "echo OK",
+    "integ": "node_modules/mocha/bin/mocha test/integ.js"
+  },
+  "author": "garden.io <info@garden.io>",
+  "license": "ISC",
+  "dependencies": {
+    "express": "^4.16.2",
+    "request": "^2.83.0",
+    "request-promise": "^4.2.2"
+  },
+  "devDependencies": {
+    "mocha": "^5.1.1",
+    "supertest": "^3.0.0"
+  }
+}

examples/deployment-strategies/frontend/test/integ.js

@@ -0,0 +1,17 @@
+const supertest = require("supertest")
+const { app } = require("../app")
+
+describe('GET /call-backend', () => {
+  const agent = supertest.agent(app)
+
+  it('should respond with a message from the backend service', (done) => {
+    agent
+      .get("/call-backend")
+      .expect(200, { message: "Backend says: 'Hello from Go!'" })
+      .end((err) => {
+        if (err) return done(err)
+        done()
+      })
+  })
+})
+

examples/deployment-strategies/garden.yml

@@ -0,0 +1,28 @@
+kind: Project
+name: deployment-strategies
+environments:
+  # Default deployment strategy
+  - name: local
+    providers:
+      - name: local-kubernetes
+  # Default deployment strategy.
+  # Same as above but explicit
+  - name: local-default
+    providers:
+      - name: local-kubernetes
+        deploymentStrategy: rolling
+  # Blue-green deployment strategy.
+  - name: local-blue-green
+    providers:
+      - name: local-kubernetes
+        deploymentStrategy: blue-green
+  # Testing environment
+  - name: testing
+    providers:
+      - name: kubernetes
+        context: gke_garden-dev-200012_europe-west1-b_garden-dev-1
+        namespace: deployment-strategies-testing-${local.env.CIRCLE_BUILD_NUM || local.username}
+        defaultHostname: deployment-strategies-testing.dev-1.sys.garden
+        buildMode: cluster-docker
+        deploymentStrategy: blue-green
+

garden-service/src/config/common.ts

@@ -47,6 +47,7 @@ interface MetadataKeys {
   internal?: boolean
   deprecated?: boolean
   extendable?: boolean
+  experimental?: boolean
 }
 
 // Unfortunately we need to explicitly extend each type (just extending the AnySchema doesn't work).

garden-service/src/docs/config.ts

@@ -13,8 +13,8 @@ import linewrap from "linewrap"
 import titleize from "titleize"
 import humanize from "humanize-string"
 import { resolve } from "path"
-import { get, flatten, startCase, uniq } from "lodash"
 import { projectSchema, environmentSchema } from "../config/project"
+import { get, flatten, startCase, uniq, find } from "lodash"
 import { baseModuleSpecSchema } from "../config/module"
 import handlebars = require("handlebars")
 import { joiArray, joi } from "../config/common"
@@ -228,6 +228,10 @@ function renderMarkdownLink(description: NormalizedDescription) {
 
 function makeMarkdownDescription(description: NormalizedDescription, titlePrefix = "") {
   const { formattedType, required, allowedValues, defaultValue } = description
+  let experimentalFeature = false
+  if (description.meta) {
+    experimentalFeature = find(description.meta, attr => attr.experimental) || false
+  }
 
   const parentDescriptions = getParentDescriptions(description)
   const title = renderMarkdownTitle(description, titlePrefix)
@@ -256,6 +260,7 @@ function makeMarkdownDescription(description: NormalizedDescription, titlePrefix
   return {
     ...description,
     breadCrumbs,
+    experimentalFeature,
     formattedExample,
     title,
     table,

garden-service/src/docs/templates/config-partial.hbs

@@ -5,6 +5,9 @@
 
 {{{breadCrumbs}}}
 {{/if}}
+{{#if experimentalFeature}}
+> ⚠️ **Experimental**: this is an experimental feature and the API might change in the future.  
+{{/if}}
 {{#if description}}
 
 {{{description}}}

garden-service/src/plugins/kubernetes/config.ts

@@ -57,11 +57,15 @@ interface KubernetesStorage {
 
 export type ContainerBuildMode = "local-docker" | "cluster-docker" | "kaniko"
 
+export type DefaultDeploymentStrategy = "rolling"
+export type DeploymentStrategy = DefaultDeploymentStrategy | "blue-green"
+
 export interface KubernetesBaseConfig extends ProviderConfig {
   buildMode: ContainerBuildMode
   context: string
   defaultHostname?: string
   defaultUsername?: string
+  deploymentStrategy?: DeploymentStrategy
   forceSsl: boolean
   imagePullSecrets: ProviderSecretRef[]
   ingressHttpPort: number
@@ -249,6 +253,17 @@ export const kubernetesConfigBase = providerConfigBaseSchema
       .example("api.mydomain.com"),
     defaultUsername: joiIdentifier()
       .description("Set a default username (used for namespacing within a cluster)."),
+    deploymentStrategy: joi.string()
+      .default("rolling")
+      .allow("rolling", "blue-green")
+      .description(dedent`
+        Defines the strategy for deploying the project services.
+        Default is "rolling update" and there is experimental support for "blue/green" deployment.
+        The feature only supports modules of type \`container\`: other types will just deploy using the default strategy.
+      `)
+      .meta({
+        experimental: true,
+      }),
     forceSsl: joi.boolean()
       .default(false)
       .description(