Accessing ElasticSearch in TestContainer

During the Unit test or Integration test, it may need to verify if a document having been persisted successfully.  

Using UI tool

Using command

docker ps to list all containers, and find out elastic container port(exposure port) number

ac8dec5773de   docker.elastic.co/elasticsearch/elasticsearch:8.1.3   "/bin/tini -- /usr/l…"   4 days ago       Up 4 days       0.0.0.0:64595->9200/tcp, 0.0.0.0:64596->9300/tcp   vigilant_pike

List all index                                

curl localhost:62864/_cat/indices -u elastic:test_password 

-u user:pasword                                

curl localhost:62864/solution-build/_search -u elastic:test_password

solution-build: ref. to a specified index

Kubernetes

Terms

Cluster: a set of nodes.

Node:  a virtual machine(VM) or physical machine. 

Master node: managing working workers.

Worker node: running applications.

Pod: a pod is the smallest deployable unit in K8s and not containers. A pod enclose containers and volumes(used for sharing data among containers). A pod has a unique IP address. 

Run K8 locally

Minikube:  installing docker + minikube

Kubectl

K8 command line tool,  providing commands to gain your cluster residing in the minikube

then we may deploy, inspect, edit resources, debug, and view logs.

minikube start > start the k8

kubectl get nodes> showing all nodes running in the k8

kubectl get pods -A > showing all pods in all namespaces

creating k8 deployment.yml VC.

kubectl apply -f deployment.yml

kubectl get svc>  get service(defined in deployment YAML file service section)

minikube service myapp : access service port

start tunnel for service myapp via URL

Thread Resources

 A Java thread uses 20M memory space and needs about 10ms to launch it. 

So for a laptop having 16G memory, it can host about 800 threads.