Decide on a builder that contains buildpacks that support this application.
pack set-default-builder cloudfoundry/cnb:bionic
Auto-detect this application against the builder's buildpacks:
pack build starkandwayne/sample-app-nodejs --path .
The output will show that the NodeJS and Yarn buildpacks are used to create the runnable Docker image:
===> DETECTING
[detector] Trying group 1 out of 12 with 14 buildpacks...
[detector] ======== Results ========
[detector] skip: Cloud Foundry Archive Expanding Buildpack
[detector] pass: Cloud Foundry OpenJDK Buildpack
[detector] skip: Cloud Foundry Build System Buildpack
[detector] fail: Cloud Foundry JVM Application Buildpack
[detector] skip: Cloud Foundry Spring Boot Buildpack
[detector] skip: Cloud Foundry Apache Tomcat Buildpack
[detector] skip: Cloud Foundry DistZip Buildpack
[detector] skip: Cloud Foundry Procfile Buildpack
[detector] skip: Cloud Foundry Azure Application Insights Buildpack
[detector] skip: Cloud Foundry Debug Buildpack
[detector] skip: Cloud Foundry Google Stackdriver Buildpack
[detector] skip: Cloud Foundry JDBC Buildpack
[detector] skip: Cloud Foundry JMX Buildpack
[detector] pass: Cloud Foundry Spring Auto-reconfiguration Buildpack
[detector] Trying group 2 out of 12 with 2 buildpacks...
[detector] ======== Results ========
[detector] pass: Node Engine Buildpack
[detector] pass: Yarn Buildpack
These two buildpacks are then applied in sequence against the application:
===> BUILDING
[builder] -----> Node Engine Buildpack 0.0.26
[builder] Node Engine 10.16.2: Contributing to layer
[builder] Downloading from https://buildpacks.cloudfoundry.org/dependencies/node/node-10.16.2-linux-x64-cflinuxfs3-9d21a165.tgz
[builder] Verifying checksum
[builder] Expanding to /layers/org.cloudfoundry.node-engine/node
[builder] Writing NODE_HOME to shared
[builder] Writing NODE_ENV to shared
[builder] Writing NODE_MODULES_CACHE to shared
[builder] Writing NODE_VERBOSE to shared
[builder] Writing NPM_CONFIG_PRODUCTION to shared
[builder] Writing NPM_CONFIG_LOGLEVEL to shared
[builder] Writing WEB_MEMORY to shared
[builder] Writing WEB_CONCURRENCY to shared
[builder] Writing .profile.d/0_memory_available.sh
[builder] -----> Yarn Buildpack 0.0.18
[builder] Yarn 1.17.3: Contributing to layer
[builder] Downloading from https://buildpacks.cloudfoundry.org/dependencies/yarn/yarn-1.17.3-any-stack-e3835194.tar.gz
[builder] Verifying checksum
[builder] NODE_HOME Value /layers/org.cloudfoundry.node-engine/node
[builder] Expanding to /layers/org.cloudfoundry.yarn/yarn
[builder] Node Dependencies 0560d3380dc3613e4e8359b4a62121acae182faa262ec51a55b6540b9ad4468e: Contributing to layer
[builder] NODE HOME VALUE /layers/org.cloudfoundry.node-engine/node
[builder]
[builder] Running yarn in online mode
[builder] yarn install v1.17.3
[builder] [1/4] Resolving packages...
[builder] [2/4] Fetching packages...
[builder] [3/4] Linking dependencies...
[builder] [4/4] Building fresh packages...
[builder] Done in 2.23s.
[builder] yarn.lock and package.json match
[builder] Writing NODE_PATH to shared
[builder] Writing PATH to shared
[builder] Writing npm_config_nodedir to shared
[builder] Process types:
[builder] web: yarn start
Running pack build a second time will be faster as it reuses cached layers:
===> BUILDING
[builder] -----> Node Engine Buildpack 0.0.26
[builder] Node Engine 10.16.2: Reusing cached layer
[builder] -----> Yarn Buildpack 0.0.18
[builder] Yarn 1.17.3: Reusing cached layer
[builder] Node Dependencies 0560d3380dc3613e4e8359b4a62121acae182faa262ec51a55b6540b9ad4468e: Reusing cached layer
[builder] Process types:
[builder] web: yarn start
[builder] Removing unused layers
[builder] modules_cache
kubectl apply -f pod.yaml
kubectl get pods
kubectl delete -f pod.yaml
kubectl apply -f deployment.yaml
kubectl get all
curl <LB>
In one terminal:
watch "curl -sS <LB>"
In another, watch pod changes:
kubectl get pods -w
In another, create :0.0.2 image and deploy:
- Edit
server.js pack build starkandwayne/sample-app-nodejs:0.0.2 --no-pull --publish- Edit
deployment.yamlto use:0.0.2 kubectl apply -f deployment.yaml
kubectl delete -f deployment.yaml
Kpack is an alternate approach to Cloud Native Buildpack lifecycle management. Rather than run pack on local machine, kpack is a system running atop your Kubernetes cluster that continuously monitors Git repositories and generates updated OCI images for any new commits.
kpack does not wrap pack, rather they both share the CNB lifecycle project to perform the same sequence for discovery and applying buildpacks to source code.
The kpack-image.yaml assumes you have a service account service-account setup, and a CNB builder resource named cflinuxfs3-builder. Any builder can be used, as long as it can support this NodeJS application.
$ kubectl get serviceaccounts,builder.build.pivotal.io
NAME SECRETS AGE
serviceaccount/default 1 5m10s
serviceaccount/service-account 3 4m47s
NAME AGE
builder.build.pivotal.io/cflinuxfs3-builder 4m
To initiate the first kpack build of this Git repository into an OCI/docker image:
kubectl apply -f kpack-image.yaml
This image resource initiates an initial build:
$ kubectl get images,builds
NAME LATESTIMAGE READY
image.build.pivotal.io/sample-app-nodejs Unknown
NAME IMAGE SUCCEEDED
build.build.pivotal.io/sample-app-nodejs-build-1-zd2ht Unknown
You can stream the in-progress CNB lifecycle with kpack's logs CLI:
logs -image sample-app-nodejs
The initial build may take a minute whilst it initially clones the Git repo, etc.
The image and build are now updated with the resulting OCI ID for the target registry:
$ kubectl get images,builds
NAME LATESTIMAGE READY
image.build.pivotal.io/sample-app-nodejs index.docker.io/starkandwayne/sample-app-nodejs@sha256:bf7ccdbb7c4790748c8613e9f7aac11de529bcb9cbb84ceea56f52045dbfe485 True
NAME IMAGE SUCCEEDED
build.build.pivotal.io/sample-app-nodejs-build-1-zd2ht index.docker.io/starkandwayne/sample-app-nodejs@sha256:bf7ccdbb7c4790748c8613e9f7aac11de529bcb9cbb84ceea56f52045dbfe485 True
We can now deploy our application to Kubernetes with this new OCI by editing deployment.yaml and replacing the image: index.docker.io... line with the full image ID index.docker.io/starkandwayne/sample-app-nodejs@sha256:bf7ccdbb7c4790748c8613e9f7aac11de529bcb9cbb84ceea56f52045dbfe485 from the example above.
$ kubectl apply -f deployment.yaml
deployment.apps/sample-app-nodejs created
service/sample-app-nodejs created
We can watch for the deployment's service to be allocated its load balancer:
$ kubectl get services -w
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.99.0.1 <none> 443/TCP 12m
sample-app-nodejs LoadBalancer 10.99.12.88 <pending> 80:30653/TCP 16s
sample-app-nodejs LoadBalancer 10.99.12.88 35.189.19.51 80:30653/TCP 61s
The application can now be reached via the LoadBalancer's IP:
$ curl 35.189.19.51
Hello World!
In another terminal, poll this endpoint to observe the future change:
$ watch curl -sS 35.189.19.51
If in server.js, I change Hello World! to Hello kpack, save, commit, and push, then kpack will discover the new commit and start a new build:
$ git commit -m "test hello kpack"
$ git push
$ kubectl get builds -w
NAME AGE
sample-app-nodejs-build-1-zd2ht 11m
sample-app-nodejs-build-2-gqljg 0s
Once the new build-2 has been created, we can switch to logs and stream its output:
logs -image sample-app-nodejs
The build sequence is much faster this time.
We now have one image, but two builds:
$ kubectl get images,builds
NAME LATESTIMAGE READY
image.build.pivotal.io/sample-app-nodejs index.docker.io/starkandwayne/sample-app-nodejs@sha256:a2fd6417143a37cd27467f9bf38c42b8d9faaf031b2769e63ea5d8fa10180a4c True
NAME IMAGE SUCCEEDED
build.build.pivotal.io/sample-app-nodejs-build-1-zd2ht index.docker.io/starkandwayne/sample-app-nodejs@sha256:bf7ccdbb7c4790748c8613e9f7aac11de529bcb9cbb84ceea56f52045dbfe485 True
build.build.pivotal.io/sample-app-nodejs-build-2-gqljg index.docker.io/starkandwayne/sample-app-nodejs@sha256:a2fd6417143a37cd27467f9bf38c42b8d9faaf031b2769e63ea5d8fa10180a4c True
As before, update deployment.yaml image: index.docker.io... with the new OCI ID:
spec:
containers:
- name: sample-app-nodejs
image: index.docker.io/starkandwayne/sample-app-nodejs@sha256:a2fd6417143a37cd27467f9bf38c42b8d9faaf031b2769e63ea5d8fa10180a4cAnd apply the updated deployment:
$ kubectl apply -f deployment.yaml
deployment.apps/sample-app-nodejs configured
service/sample-app-nodejs unchanged
The curl terminal will intermittently show both Hello World! and Hello kpack! until all containers are replaced with the new image:
$ kubectl get pods -w
NAME READY STATUS RESTARTS AGE
sample-app-nodejs-64f94f848d-4r94q 1/1 Terminating 0 8m4s
sample-app-nodejs-64f94f848d-5sp5q 1/1 Running 0 8m4s
sample-app-nodejs-9c58f6897-5wnss 1/1 Running 0 23s
sample-app-nodejs-9c58f6897-qkh4b 0/1 ContainerCreating 0 1s
sample-app-nodejs-9c58f6897-xqbm5 1/1 Running 0 12s
sample-app-nodejs-build-1-zd2ht-build-pod 0/1 Completed 0 14m
sample-app-nodejs-build-2-gqljg-build-pod 0/1 Completed 0 3m12s
sample-app-nodejs-64f94f848d-4r94q 0/1 Terminating 0 8m4s
sample-app-nodejs-64f94f848d-4r94q 0/1 Terminating 0 8m5s
sample-app-nodejs-64f94f848d-4r94q 0/1 Terminating 0 8m5s
$ kubectl get pods
NAME READY STATUS RESTARTS AGE
sample-app-nodejs-9c58f6897-5wnss 1/1 Running 0 85s
sample-app-nodejs-9c58f6897-qkh4b 1/1 Running 0 63s
sample-app-nodejs-9c58f6897-xqbm5 1/1 Running 0 74s
sample-app-nodejs-build-1-zd2ht-build-pod 0/1 Completed 0 15m
sample-app-nodejs-build-2-gqljg-build-pod 0/1 Completed 0 4m14s