Unable to connect to micro service through ZUUL api gateway in docker - spring-boot

I've following services and working fine when they are deployed in localhost (through eclipse). But unable to invoke the rest service when deployed as separate docker containers.
I'm new docker and attended the tutorials to have knowledge on how this works.
Following services are running in separate docker containers and configured as follows (local environment)
Eureka
Docker IP : 172.17.0.3
Docker port mapping : 8761:8761
spring.application.name=naming-server
server.port=8761
Zuul API gate way
Docker IP : 172.17.0.4
Docker port mapping : 8765:8765
spring.application.name=gateway-server
server.port=8765
User service
Docker IP : 172.17.0.5
Docker port mapping : 8101:8101
spring.application.name=user-service
server.port=8101
Registered services info in Eureka
Application AMIs Availability Zones Status
USER-SERVICE n/a (1) (1) UP (1) - de4396a354ea:user-service:8101
API-GATEWAY n/a (1) (1) UP (1) - e5dd509065cd:api-gateway:8765
When tried to invoke the service in "User service" through gateway, it's throwing exception
com.netflix.zuul.exception.ZuulException: Forwarding error
at org.springframework.cloud.netflix.zuul.filters.route.RibbonRoutingFilter.handleException(RibbonRoutingFilter.java:198) ~[spring-cloud-netflix-zuul-2.2.0.RELEASE.jar!/:2.2.0.RELEASE]
at org.springframework.cloud.netflix.zuul.filters.route.RibbonRoutingFilter.forward(RibbonRoutingFilter.java:173) ~[spring-cloud-netflix-zuul-2.2.0.RELEASE.jar!/:2.2.0.RELEASE]
Caused by: java.net.UnknownHostException: de4396a354ea: Name or service not known
at java.base/java.net.Inet4AddressImpl.lookupAllHostAddr(Native Method) ~[na:na]
at java.base/java.net.InetAddress$PlatformNameService.lookupAllHostAddr(InetAddress.java:929) ~[na:na]
at java.base/java.net.InetAddress.getAddressesFromNameService(InetAddress.java:1515) ~[na:na]
Note: "de4396a354ea" is the container id for "User service"
Please guide on how to resolve this issue and also provide any links where I can get more info regarding deploying microservices in docker containers.

Able to resolve this by adding "eureka.instance.hostname=" property.

Related

kubernetes nodeport external ip not accessible

I have been trying to deploy the Spring Boot application on kubernetes cluseter. But somehow I can not access the rest end point from outside the cluster.
Here are the steps which i performed
Setup the kubernetes cluster using kubespray following the guide - Kubernetes Cluster setup using Kubespray
Pushed the spring boot docker image to docker hub
Created kubernetes deployment
vagrant#node1:~/spring-boot$ kubectl create deployment demo --image=rahulwagh17/kubernetes:jhooq-k8s-springboot
deployment.apps/demo created
Exposed the deployment with external IP = 1.1.1.1
kubectl expose deployment demo --type=LoadBalancer --name=demo-service --external-ip=1.1.1.1 --port=8080
service/demo-service exposed
This is how my deployment is looking
vagrant#node1:~/spring-boot$ kubectl get deployment
NAME READY UP-TO-DATE AVAILABLE AGE
demo 1/1 1 1 24s
This is how my services are looking
vagrant#node1:~/spring-boot$ kubectl get service
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
demo-service LoadBalancer 10.233.31.159 1.1.1.1 8080:30099/TCP 13s
kubernetes ClusterIP 10.233.0.1 <none> 443/TCP 23h
I can curl the rest end point within the cluster without a problem
vagrant#node1:~/spring-boot$ curl 10.233.31.159:8080/hello
Hello - Jhooq-k8s
Problem I am facing - When i am trying to curl the rest point from outside the cluster, i can not do
$ curl http://1.1.1.1:30099/hello
curl: (7) Failed to connect to 1.1.1.1 port 30099: Operation timed out
I am little new to kubernetes, so any leads or suggestions are highly appreciated
Please try via below approach:
Via Node Port:- Which means NodeIP:NodePort and in this case, please get any node-ip and then run a command
curl http://$NODE_IP:30099/hello
and you should be able to access your service.

Eureka Client: Eureka Registry server address alternative to 'localhost'

Eureka-server(MediaStoreEurekaServer): bootstrap.properties
spring.application.name=MediaStoreEurekaServer
server.port=9091
eureka.client.serviceUrl.defaultZone=http://localhost:9091/eureka}
eureka.client.register-with-eureka=false
eureka.client.fetch-registry=false
Eureka-client(Config-Server): bootstrap.properties
spring.application.name=Config-Server
server.port=9093
user.home=${HOME}
spring.cloud.config.server.native.search-locations=file://${user.home}/IdeaProjects/MediaStore/centralProperties
spring.profiles.active=native
eureka.client.serviceUrl.defaultZone=http://localhost:9091/eureka
With above 2 properties (services running on same machine), Config-Server is able to register with MediaStoreEurekaServer eureka registry server when using http://localhost:9091/eureka.
I don't want to use localhost. When I use http://MediaStoreEurekaServer:9091/eureka , Config-Server is not able to register.
Can we use something other than localhost for eureka client to find the eureka server like service or instance name? when services are running on same host
Edit 1:
This is what eureka client spring logs give when in eureka client properties file i set
eureka.client.serviceUrl.defaultZone=http://MediaStoreEurekaServer:9091/eureka
Error:
2020-05-22 20:01:02.137 ERROR 22846 --- [nfoReplicator-0] c.n.d.s.t.d.RedirectingEurekaHttpClient : Request execution error. endpoint=DefaultEndpoint{ serviceUrl='http://MediaStoreEurekaServer:9091/eureka/}
com.sun.jersey.api.client.ClientHandlerException: java.net.UnknownHostException: MediaStoreEurekaServer```

java.net.UnknownHostException - Zuul and Eureka not working inside Docker

I´ve been trying to validade my microservices on a Docker structure, where i connect everything through linking containers but i´m not having success when trying to pass through an API Gateway with Zuul.
Basically i have theses microservices:
config-server
boutique-eureka-server
api-gateway
product-service
All of these start with success but i can´t acess the product-service behing the api-gateway.
My code is all at:
https://github.com/kalilmvp/myboutique/
along with the docker commands that i´ve used.
The error usually is:
com.netflix.zuul.exception.ZuulException: Forwarding error
In my later tests i´ve been also having this error:
Caused by: java.lang.RuntimeException: java.net.UnknownHostException: product-service
You can check it on the branch docker
Docker advises not to use --link option to link the containers and therefore this switch of docker run is deprecated.
There are many problems creating end-to-end links, like for example environment variables are being shared between 2 linked containers (imagine different values of JAVA_HOME for example).
Instead try coordinating your services using docker compose or define network using docker:
$ docker network create my-net
$ docker create --name my-eureka --network my-net --publish 8888:80 eureka:latest
...
$ docker network disconnect my-net my-eureka
Find more info in the docker docs

Unable to load consul config

I'm trying to build sample microservice app using this tutorial Tutorial. jhipster v5.2.1 So I've created a gateway and an armory started consul using this command:
docker-compose -f src/main/docker/consul.yml up
While I've pointed into the armory folder writing this command :
./gradlew
I got this error :
2018-09-03 13:20:11.235 WARN 7224 --- [ restartedMain] o.s.c.c.c.ConsulPropertySourceLocator : Unable to load consul config from config/armory-swagger/
com.ecwid.consul.transport.TransportException: org.apache.http.conn.HttpHostConnectException: Connect to localhost:8600 [localhost/127.0.0.1, localhost/0:0:0:0:0:0:0:1] failed: Connection refused: connect
Could you please help me
If you are using the toolbox you have to replace localhost by the IP of your Docker machine vm. You will have to ajust the bootstrap.yml properties to point to this adress.
You should also be able to apply this trick : https://www.jhipster.tech/tips/020_tip_using_docker_containers_as_localhost_on_mac_and_windows.html
I just changed fail-fast to false in bootstrap-prod.yml
You can disable Spring Cloud Config this way.
fail-fast: false
Otherwise you have to provide proper configuration as stated above.
Or you can run this command if you have already installed consul on your development machine.
consul agent -dev

Kubernetes networking, How to transfer a variable to container

I have a K8s, currently running in single node (master+kubelet,172.16.100.81). I have an config server image which I will run it in pod. The image is talking to another pod named eureka server. Both two images are spring boot application. And eureka server's http address and port is defined by me. I need to transfer eureka server's http address and port to config pod so that it could talk to eureka server.
I start eureka server: ( pesudo code)
kubectl run eureka-server --image=eureka-server-image --port=8761
kubectl expose deployment eureka-server --type NodePort:31000
Then I use command "docker pull" to download config server image and run it as below:
kubectl run config-server --image=config-server-image --port=8888
kubectl expose deployment config-server --type NodePort:31001
With these steps, I did not find the way to transfer eureka-server http
server (master IP address 172.16.100.81:31000) to config server, are there
methods I could transer variable eureka-server=172.16.100.81:31000 to Pod config server? I know I shall use ingress in K8s networking, but currently I use NodePort.
Generally, you don't need nodePort when you want two pods to communicate with each other. A simpler clusterIP is enough.
Whenever you are exposing a deployment with a service, it will be internally discoverable from the DNS. Both of your exposed services can be accessed using:
http://config-server.default:31001 and http://eureka-server.default:31000. default is the namespace here.
172.16.100.81:31000 will make it accessible from outside the cluster.

Resources