addressing comments on PR knative#99 (knative#99)

docs/workflows.md

@@ -1 +1,105 @@
-TODO
+# Workflows
+
+The purpose of this section of the Kn documentation is to list common workflows or use-cases for the Knative CLI. This is a live document, meant to be updated as we learn more about good ways to use `kn`.
+
+## Basic
+
+In this basic worflow we show the CRUD (create, read, update, delete) operations on a service. We use a well known [simple Hello World service](https://github.com/knative/docs/tree/master/docs/serving/samples/hello-world/helloworld-go) that reads the environment variable `TARGET` and prints it as output.
+
+* Create a service from image in `default` namespace
+
+```bash
+$ kn service create hello --image gcr.io/knative-samples/helloworld-go --env TARGET=Knative
+```
+
+* Curl service endpoint
+
+```bash
+curl '-sS' '-H' 'Host: hello.default.example.com' 'http://xxx.xx.xxx.xx   '
+Hello Knative!
+```
+
+Where `http://xxx.xx.xxx.xx` is your Knative installation ingress.
+
+* List service
+
+```bash
+$ kn service list
+$ hello
+```
+
+* Update service
+
+```bash
+$ kn service update hello --env TARGET=Kn
+```
+
+The service's environment variable `TARGET` is now set to `Kn`
+
+<!-- TODO: include when `service get` is merged
+* Get service
+
+```bash
+$ kn service get hello
+#TODO ouput
+```
+
+TODO: observation(s) if any
+-->
+
+* Describe service
+
+```bash
+$ kn service describe hello
+apiVersion: knative.dev/v1alpha1
+kind: Service
+metadata:
+  creationTimestamp: "2019-05-09T21:14:41Z"
+  generation: 1
+  name: hello
+  namespace: default
+  resourceVersion: "28795267"
+  selfLink: /apis/serving.knative.dev/v1alpha1/namespaces/default/services/hello
+  uid: 760e1b9a-729f-11e9-9180-9ae5104abc98
+spec:
+  generation: 2
+  runLatest:
+    configuration:
+      revisionTemplate:
+        metadata:
+          creationTimestamp: null
+        spec:
+          concurrencyModel: Multi
+          container:
+            env:
+            - name: TARGET
+              value: Kn
+            name: ""
+            resources: {}
+status:
+  conditions:
+  - lastTransitionTime: "2019-05-09T21:14:52Z"
+    status: "True"
+    type: RoutesReady
+  - lastTransitionTime: "2019-05-09T21:26:42Z"
+    status: "True"
+    type: ConfigurationsReady
+  domain: hello.default.example.com
+  domainInternal: hello.default.svc.cluster.local
+  latestCreatedRevisionName: hello-00002
+  latestReadyRevisionName: hello-00001
+  observedGeneration: 2
+  traffic:
+  - configurationName: hello
+    percent: 100
+    revisionName: hello-00001
+```
+
+* Delete service
+
+```bash
+$ kn service delete hello
+$ Deleted 'hello' in 'default' namespace.
+```
+
+You can then issue the same `$ kn service list` command to verify that the service was deleted.