Update k8gb curl demo to be usable for real deployments (#506)

* Update k8gb curl demo to be usable for real deployments

* Make demo script https ready with optional verbose mode
* Simple docker build targets
* Paramterize hosts under test in main Makefile
* Simplify demo targets and make them single parametrized `demo`

Useful to survive end-to-end presentations when your local dns
got slammed just before the demo

Signed-off-by: Yury Tsarev <yury.tsarev@absa.africa>

* Implement PR suggestions

Signed-off-by: Yury Tsarev <yury.tsarev@absa.africa>

CONTRIBUTING.md

@@ -217,5 +217,42 @@ These instructions will help you to set up and use local website authoring and t
 - Open the `http://localhost:4000/` page in your browser.
 - Website will automatically rebuild and refresh in the browser to accommodate the related code changes.
 
+## End-to-end demo helper
+
+The demo helper is designed to work with `podinfo` that was deployed by
+
+```sh
+make deploy-test-apps
+```
+
+It will configure `podinfo` to expose geotag as part of an HTTP response.
+
+To test and/or demonstrate continuous query to GSLB enabled endpoint execute
+
+```sh
+make demo DEMO_URL=https://failover.test.exampledns.tk
+```
+
+The happy path will look like:
+
+```sh
+[Thu May 27 15:35:26 UTC 2021] ...
+
+200  "message": "eu-west-1",
+
+[Thu May 27 15:35:31 UTC 2021] ...
+
+200
+  "message": "eu-west-1",
+[Thu May 27 15:35:36 UTC 2021] ...
+```
+
+The sources for demo helper images can be found [here](deploy/test-apps/curldemo/)
+
+To enable verbose debug output declare `DEMO_DEBUG=1` like
+```sh
+make demo DEMO_URL=https://failover.test.exampledns.tk DEMO_DEBUG=1
+```
+
 ---
 Thanks for contributing!

Makefile

@@ -44,6 +44,8 @@ EXT_GSLB_CLUSTERS_GEO_TAGS ?= us
 EDGE_DNS_SERVER ?= 1.1.1.1
 EDGE_DNS_ZONE ?= example.com
 DNS_ZONE ?= cloud.example.com
+DEMO_URL ?= http://failover.cloud.example.com
+DEMO_DEBUG ?=0
 
 ifndef NO_COLOR
 YELLOW=\033[0;33m
@@ -102,14 +104,9 @@ debug-idea: export WATCH_NAMESPACE=test-gslb
 debug-idea:
 	$(call debug,debug --headless --listen=:2345 --api-version=2)
 
-.PHONY: demo-roundrobin
-demo-roundrobin: ## Execute round-robin demo
-	@$(call demo-host, "roundrobin.cloud.example.com")
-
-.PHONY: demo-failover
-demo-failover: ## Execute failover demo
-	@$(call demo-host, "failover.cloud.example.com")
-
+.PHONY: demo
+demo: ## Execute end-to-end demo
+	@$(call demo-host, $(DEMO_URL))
 
 # spin-up local environment
 .PHONY: deploy-full-local-setup
@@ -436,7 +433,7 @@ define testapp-set-replicas
 endef
 
 define demo-host
-	kubectl run -it --rm k8gbdemo --restart=Never --image=absaoss/k8gbdemocurl  \
+	kubectl run -it --rm k8gb-demo --restart=Never --image=absaoss/k8gb-demo-curl --env="DEBUG=$(DEMO_DEBUG)" \
 	"`$(K8GB_COREDNS_IP)`" $1
 endef
 

deploy/test-apps/curldemo/Makefile

@@ -0,0 +1,22 @@
+# Copyright 2021 The k8gb Contributors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# Generated by GoLic, for more details see: https://github.com/AbsaOSS/golic
+.PHONY: docker-build
+docker-build:
+	docker build . -t absaoss/k8gb-demo-curl
+
+.PHONY: docker-push
+docker-push:
+	docker push absaoss/k8gb-demo-curl

deploy/test-apps/curldemo/k8gbcurl.sh

@@ -4,16 +4,21 @@
 # $1 - nameserver to use usually k8gb-coredns service ip
 # $2 - test fqdn to resolve in demo loops
 
+if [ "$DEBUG" == 1 ]
+then
+   set -x
+fi
+
 if [ "$1" != '--local' ]
 then
     echo "nameserver $1" > /etc/resolv.conf
 fi
 
-fqdn="$2"
+url="$2"
 
 while true
 do
-  curl -k -s -w "%{stderr}\n%{http_code}\n" --location --request GET "${fqdn}" |grep message
+  curl -k -s -w "%{stderr}\n%{http_code}\n" --location --request GET "${url}" |grep message
   sleep 5
   echo "[`date`] ..."
 done