I have configured mysql cluster service and I am using the that service instead of hostname in jdbc url in my application.properties. It is not resolving. But when I use the minikube URL, it is connecting correctly. Shouldn't DNS resolution happen for jdbc url as well in application.properties for a java project ?
Just as #sfgroups mentioned, it is highly likely that the service has not been properly registered. Maybe you are using a different namespace or simply the service is not available. In order to check that:
Run kubectl get svc and kubectl get endpoints to check if the service is registered and the mysql pods selected. It may sound silly but I advise you to check if the service name you are using is correct.
If it is registered, try kubectl get pods, get the ID of your jdbc pod and launch kubectl exec -ti <ID> nslookup <servicename>. This will give you a hint if the dns resolution is working or not.
If it is not resolving, then check in minikube addons list that dns is enabled. If it is disabled, enable it (you will need to wait a little bit) and try again.
Related
I'm running Docker Desktop 3.6.0 on Windows 10 with WSL2.
When I try to enable Kubernetes I only see "Failed to start" within the Docker Desktop UI.
Docker itself works fine. Not sure how I can get any further logs.
Here the output from kubectl version:
kubectl version
Client Version: version.Info{Major:"1", Minor:"21", GitVersion:"v1.21.3", GitCommit:"ca643a4d1f7bfe34773c74f79527be4afd95bf39", GitTreeState:"clean", BuildDate:"2021-07-15T21:04:39Z", GoVersion:"go1.16.6", Compiler:"gc", Platform:"windows/amd64"}
Error from server (InternalError): an error on the server ("") has prevented the request from succeeding
From other posts it seems that and internet connections is required for initial setup:
https://stackoverflow.com/a/52765732/1100559
https://stackoverflow.com/a/63318739/1100559
Direct internet connection is not possible on my work environment, I can only manually copy required images on my pc.
I also do not have admin access.
Is there a way to manually setup Kubernetes on Docker Desktop or somehow indicate where the required images can be found?
I have a nexus Docker repository where I can push required images to.
I have changed the ~\.docker\daemon.json and added my docker repository in insecure-registries. After first login docker is able to pull images from there and run them.
Already tried to reset or enable and disable Kubernetes. Also deleting ~/.kube/config did not work.
High level answer...
Get a docker registry
If you work for an old skool cool enterprise; use JFrog Artifactory
If you just want to get it to work; use Harbor
GitHub and GitLab (depending on license) have registries available too...
Edit the docker daemon on the kubernetes nodes (your workstation) to only pull from these registries.
if redhat; /etc/containers/registries.conf
if debain; /etc/docker/daemon.json
you might be able to hack a /etc/hosts entry too...
Populate the new registry
Run kubernetes and yoiu should be good to go. Depending on the configuration you choose you may need to add a registry credential secret.
I am trying to deploy spring boot docker image stored at Docker Registry to Cloud Run.
However, when I deployed the image, I got the error;
Cloud Run error: Container failed to start. Failed to start and then listen on the port defined by the PORT environment variable. Logs for this revision might contain more information.
I understand this could be caused by port and address setting, so I fixed these parts referring the official doc, though still experiencing the same error. Concretely, I set these things as below, on application.yml.
server:
port: ${PORT:8080}
address: ${ADDRESS:localhost}
I understand PORT variable would be passed by Cloud Run(in my case, port num is set to 8080 on Cloud Run). And also ADDRESS will be passed to by myself(the value is 0.0.0.0, referring the official doc).
For reference, the below is my Dockerfile building spring boot docker image;
# Stage1 - execute build process
FROM openjdk:14-jdk-alpine as build_process
WORKDIR /back_end
COPY . .
RUN ./gradlew build -x test
# Stage2 - boot app with the build output above
FROM openjdk:14-jdk-alpine
EXPOSE ${PORT}
COPY --from=build_process /back_end/build/libs/back_end-0.0.1-SNAPSHOT.jar ./app.jar
RUN adduser -D user
USER user
ENTRYPOINT ["sh","-c","java -jar app.jar"]
Any help would be really appreciated. Thank you so much for reading!
I figured it out why my docker image had failed Cloud Run's health check. After all, it is not about Port and IP address, but about the timing when the health check process executes.
The health check process seems to start immediately once the image is deployed, though my case it took almost 30 secs to launch spring boot tomcat server after deploying to Cloud Run.
That led to the failure of the health check process, so I fixed settings to launch tomcat server immediately too, which solved the issue I posted.
I have developed Spring Boot applications. I have setup admin and RabbitMQ as well as spring cloud bus. When i refresh the end points of applications, it refreshes the properties for application.
Can anyone please help me how to setup RabbitMQ in kubernetes now? I did research to an extent and found in few articles that it needs to be deployed as "Statefulset" rather than "Deployment" https://notallaboutcode.blogspot.de/2017/09/rabbitmq-on-kubernetes-container.html. I could not get why this needs to be done exactly. Also any useful link on deploying RabbitMQ in kubernetes would help.
It depends on what you're looking to do and what tools you have available. I guess your current setup is much like that described in http://www.baeldung.com/spring-cloud-bus. One approach to porting that to kubernetes might be to try to get your setup working with docker-compose first and then you could port that docker-compose to kubernetes deployment descriptors.
A simple way to deploy rabbitmq in k8s would be to set up a Deployment using a rabbitmq docker image. An example of this is https://github.com/Activiti/activiti-cloud-examples/blob/fe732096b5a19de0ad44879a399053f6ae02b095/kubernetes/kubectl/infrastructure.yml#L17. (Notice that file isn't radically different from a docker-compose file so you could port from one to the other.) But that won't be persisting data outside of the Pods so if the cluster were to go down or the Pod/s were to go down then you'd lose message data. The persistence is ephemeral.
So to have non-ephemeral persistence you could instead use a StatefulSet as in the example you point to. Another example is https://wesmorgan.svbtle.com/rabbitmq-cluster-on-kubernetes-with-statefulsets
If you are using helm (or can use helm) then you could use the rabbitmq helm chart, which uses a StatefulSet.
But if your only reason for needing the bus is to trigger refreshes when property changes happen then there are alternative paths available with Kubernetes. I'm guessing you need the hot reloads so you could look at using https://github.com/fabric8io/spring-cloud-kubernetes#propertysource-reload Or if you need the config to come from git specifically then you could look at http://fabric8.io/guide/develop/configuration.html (If you didn't need the hot reloads or git then you could consider versioning your configmaps and upgrading them with your application upgrades like in https://dzone.com/articles/configuring-java-apps-with-kubernetes-configmaps-a )
If you have installed helm in your cluster
helm install stable/rabbitmq
This will install rabbitmqserver on your cluster, the following commands are for obtaining the password and erlang cookie, replace prodding-wombat-rabbitmq for w/e kubernetes decides to name the pod.
kubectl get secret --namespace default prodding-wombat-rabbitmq -o jsonpath="{.data.rabbitmq-password}" | base64 --decode
kubectl get secret --namespace default prodding-wombat-rabbitmq -o jsonpath="{.data.rabbitmq-erlang-cookie}" | base64 --decode
To connect to the pod:
export POD_NAME=$(kubectl get pods --namespace default -l "app=prodding-wombat-rabbitmq" -o jsonpath="{.items[0].metadata.name}")
Then prorxy to localhost so you can connect in your browswer
kubectl port-forward $POD_NAME 5672:5672 15672:15672
I'm developing a POC over IBM HyperLedger Blockchain. I have a business network developed and deployed in IBM Cloud. I can generate a working local API REST, but cannot make it work on cloud, on the deployed IP.
I'm following this guide:
https://ibm-blockchain.github.io/interacting/
You just have to execute the following command:
./create/create_composer-rest-server.sh --business-network-card MY_BIZNET_CARD_NAME
But it doesn't deploy anything, and get the following (more related to kubernetes than blockchain).
Preparing yaml file for create composer-rest-server
Creating composer-rest-server pod
Running: kubectl create -f /Users/sm/jsblock/ibm-container-service/cs-offerings/scripts/../kube-configs/composer-rest-server.yaml
The connection to the server localhost:8080 was refused - did you specify the right host or port?
the server doesn't have a resource type "svc"
Creating composer-rest-server service
Running: kubectl create -f /Users/sm/jsblock/ibm-container-service/cs-offerings/scripts/../kube-configs/composer-rest-server-services-free.yaml
The connection to the server localhost:8080 was refused - did you specify the right host or port?
Composer rest server created successfully
Any ideas? Thanks too much.
You need to ensure you have a correct kube config setup. Step 10 in https://ibm-blockchain.github.io/setup/ provides the details to set up KUBECONFIG as the error suggests that either it is not configured or not configured correctly.
The document you refer to https://ibm-blockchain.github.io/interacting/ is being updated and should be available soon.
When you run the command ./create/create_composer-rest-server.sh --business-network-card MY_BIZNET_CARD_NAME - should be the name of the Network Admin for the network you deployed, NOT the PeerAdmin card so it will be something like ./create/create_composer-rest-server.sh --business-network-card admin#perishable-network
Look like it's an issue of acceess control. You should make sure again you are running with Local Admin configuration.it will help you to run queries
I am trying to set up a redis sentinel as a windows service on a Azure VM (IaaS).
I am using the MS OpenTech port of Redis for Windows and running the following command...
redis-server --service-install --service-name rdsent redis.sentinel.conf --sentinel
This command installs the service on my system but when I try to start this service either through the services control panel or through the following command...
redis-server --service-run --service-name rdsent redis.sentinel.conf --sentinel
Then the service fails to start with the following error...
HandleServiceCommands: system error caught. error code=1063, message = StartServiceCtrlDispatcherA failed: unknown error
Am I missing something here?
Please someone help me start this service make it work properly.
I had the same problem, and mine was related to my sentinel config. A number of articles I have found have some incorrect examples, so my service install would not work until the configuration was correct. Anyway, here is what you need at a minimum for your sentinel config (for Windows Redis 2.8.17):
sentinel monitor <name of redis cache> <server IP> <port> 2
sentinel down-after-milliseconds <name of redis cache> 4000
sentinel failover-timeout <name of redis cache> 180000
sentinel parallel-syncs <name of redis cache> 1
Once you have that setup, the original Redis service command above will work.
According to MSOpenTech, the following command should install Redis Sentinel as a service:
redis-server --service-install --service-name Sentinel1 sentinel.1.conf --sentinel
But when I used that command the installed service wouldn't start: it would immediately fail with error 1067, "The process terminated unexpectedly." Looking at service entry I'm guessing the problem is that the --service-name parameter isn't being filtered and ends up as part of the service executable path.
What I did find to work is installing the service manually with the SC command:
SC CREATE Sentinel1 binpath= "\"C:\Program Files\Redis\redis-server.exe\" --service-run sentinel.1.conf --sentinel"
Don't forget the required space after "binpath=", and obviously that path will have to reflect where you've installed redis-server.exe. Also after the service installed I edited the service entry so Redis Sentinel would run under the Network Service account.
I am using v3.0.501 and ran into the two issues below. While present it caused the service to fail on start without an error written to either the file log or the Event Log.
The configuration file must be the last parameter of the command line. If another parameter was last, such as --service-name, it would run fine when invoked the command line but would consistently fail went started as a service.
Since the service installs a Network Service by default, ensure that it has access to the directory where the log file will be written.
Once these two items were accounted for the redis as a service run smooth as silk.
Recently, I have found a way how to setup windows service for Redis and Sentinel.
During my setup, I encountered similar problem. I finally figured it out: it was caused by the configuration file path.
I have put all my configuration into my github project: https://github.com/dingyuliang/Windows-Redis-Sentinel-Config