Kubernetes tutorial
6. Deploy microservices with Skaffold
Skaffold allows us to have a seamless development workflow with Kubernetes.
To continue you must have defined the environment variable SKAFFOLD_DEFAULT_REPO and logged in with Docker to your created ACR as described in previous section.
Skaffold workflow
Skaffold uses a workflow to keep your source in sync with the Kubernetes cluster:
- Collects and watches your source code for changes
- Syncs files directly to pods when user marks them as syncable
- Builds artifacts from the source code
- Tests the built artifacts using container-structure-tests
- Tags the artifacts
- Pushes the artifacts to the ACR
- Deploys the artifacts from the ACR to the AKS cluster
- Monitors the deployed artifacts
- Cleans up deployed artifacts on exit (Ctrl+C)
Running the microservices application
The microservices-demo project has everything else we need for using Skaffold. We can just change to its directory to proceed.
$ cd ..
$ cd microservices-demo
$ skaffold run --tail
Generating tags...
- systestacr.azurecr.io/emailservice -> systestacr.azurecr.io/emailservice:v0.1.2-2-g2177813
- systestacr.azurecr.io/productcatalogservice -> systestacr.azurecr.io/productcatalogservice:v0.1.2-2-g2177813
- systestacr.azurecr.io/recommendationservice -> systestacr.azurecr.io/recommendationservice:v0.1.2-2-g2177813
- systestacr.azurecr.io/shippingservice -> systestacr.azurecr.io/shippingservice:v0.1.2-2-g2177813
- systestacr.azurecr.io/checkoutservice -> systestacr.azurecr.io/checkoutservice:v0.1.2-2-g2177813
- systestacr.azurecr.io/paymentservice -> systestacr.azurecr.io/paymentservice:v0.1.2-2-g2177813
- systestacr.azurecr.io/currencyservice -> systestacr.azurecr.io/currencyservice:v0.1.2-2-g2177813
- systestacr.azurecr.io/cartservice -> systestacr.azurecr.io/cartservice:v0.1.2-2-g2177813
- systestacr.azurecr.io/frontend -> systestacr.azurecr.io/frontend:v0.1.2-2-g2177813
- systestacr.azurecr.io/loadgenerator -> systestacr.azurecr.io/loadgenerator:v0.1.2-2-g2177813
- systestacr.azurecr.io/adservice -> systestacr.azurecr.io/adservice:v0.1.2-2-g2177813
Tags generated in 16.110141ms
Checking cache...
- systestacr.azurecr.io/emailservice: Found. Pushing
The push refers to repository [systestacr.azurecr.io/emailservice]
Skaffold will start its workflow, using the src files as sources for the microservices, and the files from kubermentes-manifest to deploy the Kubernetes associated resources.
Using the --tail switch, you will start to see messages in the console like these:
[cartservice-558bdc457b-g4bmt server] Checking CartService Health
[frontend-677bf4649b-78qq4 server] {"http.req.id":"c1c195cb-5ab4-46af-958b-9b43b70f854d","http.req.method":"GET","http.req.path":"/_healthz","http.resp.bytes":2,"http.resp.status":200,"http.resp.took_ms":0,"message":"request complete","session":"x-readiness-probe","severity":"debug","timestamp":"2019-10-22T03:55:32.234309421Z"}
[emailservice-54ffc447b8-q9md2 server] [SpanData(name='Recv.grpc.health.v1.Health.Check', context=SpanContext(trace_id=ac3badfd1dc14226b960f7189d85a926, span_id=None, trace_options=TraceOptions(enabled=True), tracestate=None), span_id='c76d223f1b5a4440', parent_span_id=None, attributes={'component': 'grpc'}, start_time='2019-10-22T03:55:32.329961Z', end_time='2019-10-22T03:55:32.330053Z', child_span_count=0, stack_trace=None, time_events=[<opencensus.trace.time_event.TimeEvent object at 0x7f20c823ccd0>, <opencensus.trace.time_event.TimeEvent object at 0x7f20c823e550>], links=[], status=None, same_process_as_parent_span=None, span_kind=1)]
The Hipster Shop demo uses a Stackdriver log monitor that is specific to Google Cloud, and its driver will try to connect several times and then give up. See the official documentation for more information.
When using the “run” command, you can press Ctrl+C to exit and the microservices application will continue to run. Also, changes to sources will not be synced to the cluster.
Browsing the shop’s website
Locate the IP that the load balancer is using, execute:
$ kubectl get service frontend-external
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
frontend-external LoadBalancer 10.0.200.147 13.73.227.79 80:31971/TCP 12m
Then open the http URL using “EXTERNAL-IP” address to see the shop’s web page, in this example: http://13.73.227.79.
If it shows <pending>, you have to wait till the external IP has been provisioned. Sometimes it can take more than 5 minutes for it to be available.
Developing and Skaffold
If you want to develop code for the microservices and have Skaffold execute its workflow to automatically publish it to the Kubernetes cluster whenever it detects a change, use:
$ skaffold dev
The “dev” command, when interrupted with Ctrl+C, will delete all resources created in the cluster when the microservices where deployed.
While it is running, if you change any of the source files of src folder, you will automatically trigger the workflow that deploys the change to the corresponding container in the cluster.
If you are deploying to a local Kubernetes installation with Minikube and a standard profile, or Docker for desktop, pushing images to the registry is automatically skipped. To do the same in other cases, see the official documentation here.
Optional: Check the status of the cluster
To get all the nodes on the default namespace in the cluster, use:
$ kubectl get nodes
Check pods from all namespaces with:
$ kubectl get pods --all-namespaces
Improvement: With the default configuration, Skaffold doesn’t use your provisioned public IP. Change it to use that.
Improvement: You could set up a CI/CD pipeline in Azure Devops portal linked to a git repository to automatically deploy the cluster when a commit to master branch is done.
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