to reproduce this case, i follow those tutorials first:
DOCKER - part
part 1
part 2
part 3
part 4
( ... All those parts was done on a ubuntu 18 virtual machine ... )
After those tutorials, this is the result:
Here you can see all the step in order to make it works on my local machine (mac os - Mojave)
KUBERNETES - part
I follow this tutorial:
part 1
And you will see the error on the next image:
All those steps are don on my local machine (mac os - Mojave)
I don't know what is the problem.
I don't know how to solve this
Can somebody help me with this, please?
I really want to understand this
Really thanks
You want to pull it from local repo which is not https, add configuration to allow pull from insecure repository. find docker.conf file which for me is in this path /etc/systemd/system/docker.service.d/docker.conf and add below line
[Service]
ExecStart=/usr/bin/dockerd -H fd:// --insecure-egistry=<repo-address>:<port>
I think that issue is caused because your did not add your dockerserver as secure registry.
You should add your registry to daemon.json file.
You have to create or modify /etc/docker/daemon.json on the machine.
$ sudo vi /etc/docker/daemon.json (you can use nano or other text editor)
Inside the file you have to add your repository. It should looks like
{
"insecure-registries" : ["mydockerserver.com:5000"]
}
After this change you must restart docker daemon using
$ sudo service docker restart
Also in your yaml you should use:
...
image: mydockerserver.com:5000/test-julie-image:latest
...
Please let me know if that helped.
This may be a bit old but I ran into this post searching for the same solutions. The link below is what worked for me:
https://kind.sigs.k8s.io/docs/user/local-registry/
When reading the script pay close attention to the code below:
# create a cluster with the local registry enabled in containerd
cat <<EOF | kind create cluster --config=-
kind: Cluster
apiVersion: kind.x-k8s.io/v1alpha4
containerdConfigPatches:
- |-
[plugins."io.containerd.grpc.v1.cri".registry.mirrors."localhost:${reg_port}"]
endpoint = ["http://${reg_name}:${reg_port}"]
EOF
AND
# Document the local registry
# https://github.com/kubernetes/enhancements/tree/master/keps/sig-cluster-lifecycle/generic/1755-communicating-a-local-registry
cat <<EOF | kubectl apply -f -
apiVersion: v1
kind: ConfigMap
metadata:
name: local-registry-hosting
namespace: kube-public
data:
localRegistryHosting.v1: |
host: "localhost:${reg_port}"
help: "https://kind.sigs.k8s.io/docs/user/local-registry/"
EOF
Even if you aren't using "kind," and you have installed a local custom solutions this code above should provide some insights or guidance.
Related
I'm using Window and learning Kubernetes, I'm trying to install ingress-nginx by running this command
kubectl apply -f https://raw.githubusercontent.com/kubernetes/ingress-nginx/controller-v0.35.0/deploy/static/provider/cloud/deploy.yaml.
It didn't work at 1st, so I copied the yaml file locally and run "kubectl apply -f" on that local file but then I got this
unable to recognize "ingress.yaml": Get https://kubernetes.docker.internal:6443/api?timeout=32s: dial tcp 127.0.0.1:6443: connectex: No connection could be made because the target machine actively refused it.
Please help me (I don't use minikube)
This is the issue with kubectl itself that doesn't see your ~/.kube/config.
Most probably you will see nothing if run
kubectl config view
apiVersion: v1
clusters: []
contexts: []
current-context: ""
kind: Config
preferences: {}
users: []
Make sure KUBECONFIG looks to your config file(~/.kube/config)
You mat also want to visit Trouble installing applications in Kubernetes github issue for more information
I am trying to change my existing deployment logic/switch to kubernetes (My server is in gcp and till now I used docker-compose to run my server.) So I decided to start by using kompose and generating services/deployments using my existing docker-compose file. After running
kompose --file docker-compose.yml convert
#I got warnings indicating Volume mount on the host "mypath" isn't supported - ignoring path on the host
After a little research I decided to use the command below to "fix" the issue
kompose convert --volumes hostPath
And what this command achieved is -> It replaced the persistent volume claims that were generated with the first command to the code below.
volumeMounts:
- mountPath: /path
name: certbot-hostpath0
- mountPath: /somepath
name: certbot-hostpath1
- mountPath: /someotherpath
name: certbot-hostpath2
- hostPath:
path: /path/certbot
name: certbot-hostpath0
- hostPath:
path: /path/cert_challenge
name: certbot-hostpath1
- hostPath:
path: /path/certs
name: certbot-hostpath2
But since I am working in my local machine
kubectl apply -f <output file>
results in The connection to the server localhost:8080 was refused - did you specify the right host or port?
I didn't want to connect my local env with gcp just to generate the necessary files, is this a must? Or can I move this to startup-gcp etc
I feel like I am in the right direction but I need a confirmation that I am not messing something up.
1)I have only one compute engine(VM instance) and lots of data in my prod db. "How do I"/"do I need to" make sure I don't lose any data in db by doing something?
2)In startup-gcp after doing everything else (pruning docker images etc) I had a docker run command that makes use of docker/compose 1.13.0 up -d. How should I change it to switch to kubernetes?
3)Should I change anything in nginx.conf as it referenced to 2 different services in my docker-compose (I don't think I should since same services also exist in kubernetes generated yamls)
You should consider using Persistent Volume Claims (PVCs). If your cluster is managed, in most cases it can automatically create the PersistentVolumes for you.
One way to create the Persistent Volume Claims corresponding to your docker compose files is using Move2Kube(https://github.com/konveyor/move2kube). You can download the release and place it in path and run :
move2kube translate -s <path to your docker compose files>
It will then interactively allow you configure PVCs.
If you had a specific cluster you are targeting, you can get the specific storage classes supported by that cluster using the below command in a terminal where you have set your kubernetes cluster as context for kubectl.
move2kube collect
Once you do collect, you will have a m2k_collect folder, which you can then place it in the folder where your docker compose files are. And when you run move2kube translate it will automatically ask you whether to target this specific cluster, and also option to choose the storage class from that cluster.
1)I have only one compute engine(VM instance) and lots of data in my
prod db. "How do I"/"do I need to" make sure I don't lose any data in
db by doing something?
Once the PVC is provisioned you can copy the data to the PVC by using kubectl cp command into a pod where the pvc is mounted.
2)In startup-gcp after doing everything else (pruning docker images
etc) I had a docker run command that makes use of docker/compose
1.13.0 up -d. How should I change it to switch to kubernetes?
You can potentially change it to use helm chart. Move2Kube, during the interactive session, can help you create helm chart too. Once you have the helm chart, all you have to do is "helm upgrade -i
3)Should I change anything in nginx.conf as it referenced to 2
different services in my docker-compose (I don't think I should since
same services also exist in kubernetes generated yamls)
If the services names are name in most cases it should work.
I've been following tutorial videos and trying to understand to build a small minimalistic application. The videos I followed are pulling containers from the registries while I'm trying to test, build and deploy everything locally at the moment if possible. Here's my setup.
I've the latest docker installed with Kubernetes enabled on mac OS.
A helloworld NodeJS application running with Docker and Docker Compose
TODO: I'd like to be able to start my instances, let's say 3 in the kubernetes cluster
Dockerfile
FROM node:alpine
COPY package.json package.json
RUN npm install
COPY . .
CMD ["npm", "start"]
docker-compose.yml
version: '3'
services:
user:
container_name: users
build:
context: ./user
dockerfile: Dockerfile
Creating a deployment file with the help of this tutorial and it may have problems since I'm merging information both from youtube as well as the web link.
Creating a miminalistic yml file for to be able to get up and running, will study other aspects like readiness and liveness later.
apiVersion: v1
kind: Service
metadata:
name: user
spec:
selector:
app: user
ports:
- port: 8080
type: NodePort
Please review the above yml file for correctness, so the question is what do I do next?
The snippets you provide are regrettably insufficient but you have the basics.
I had a Google for you for a tutorial and -- unfortunately -- nothing obvious jumped out. That doesn't mean that there isn't one, just that I didn't find it.
You've got the right idea and there are quite a few levels of technology to understand but, I commend your approach and think we can get you there.
Let's start with a helloworld Node.JS tutorial
https://nodejs.org/en/docs/guides/getting-started-guide/
Then you want to containerize this
https://nodejs.org/de/docs/guides/nodejs-docker-webapp/
For #3 below, the last step here is:
docker build --tag=<your username>/node-web-app .
But, because you're using Kubernetes, you'll want to push this image to a public repo. This is so that, regardless of where your cluster runs, it will be able to access the container image.
Since the example uses DockerHub, let's continue using that:
docker push <your username>/node-web-app
NB There's an implicit https://docker.io/<your username>/node-web-app:latest here
Then you'll need a Kubernetes cluster into which you can deploy your app
I think microk8s is excellent
I'm a former Googler but Kubernetes Engine is the benchmark (requires $$$)
Big fan of DigitalOcean too and it has Kubernetes (also $$$)
My advice is (except microk8s and minikube) don't ever run your own Kubernetes clusters; leave it to a cloud provider.
Now that you have all the pieces, I recommend you just:
kubectl run yourapp \
--image=<your username>/node-web-app:latest \
--port=8080 \
--replicas=1
I believe kubectl run is deprecated but use it anyway. It will create a Kubernetes Deployment (!) for you with 1 Pod (==replica). Feel free to adjust that value (perhaps --replicas=2) if you wish.
Once you've created a Deployment, you'll want to create a Service to make your app accessible (top of my head) this command is:
kubectl expose deployment/yourapp --type=NodePort
Now you can query the service:
kubectl get services/yourapp
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
yourapp NodePort 10.152.183.27 <none> 80:32261/TCP 7s
NB The NodePort that's been assigned (in this case!) is :32261 and so I can then interact with the app using curl http://localhost:32261 (localhost because I'm using microk8s).
kubectl is powerful. Another way to determine the NodePort is:
kubectl get service/yourapp \
--output=jsonpath="{.spec.ports[0].nodePort}"
The advantage of the approach of starting from kubectl run is you can then easily determine the Kubernetes configuration that is needed to recreate this Deployment|Service by:
kubectl get deployment/yourapp \
--format=yaml \
> ./yourapp.deployment.yaml
kubectl get service/yourapp \
--format=yaml \
> ./yourapp.service.yaml
These commands will interrogate the cluster, retrieve the configuration for you and pump it into the files. It will include some instance data too but the gist of it shows you what you would need to recreate the deployment. You will need to edit this file.
But, you can test this by first deleting the deployment and the service and then recreating it from the configuration:
kubectl delete deployment/yourapp
kubectl delete service/yourapp
kubectl apply --filename=./yourapp.deployment.yaml
kubectl apply --filename=./yourapp.service.yaml
NB You'll often see multiple resource configurations merged into a single YAML file. This is perfectly valid YAML but you only ever see it used by Kubernetes. The format is:
...
some: yaml
---
...
some: yaml
---
Using this you could merge the yourapp.deployment.yaml and yourapp.service.yaml into a single Kubernetes configuration.
What is the best way to change the source code of my application running as Kubernetes pod without creating a new version of image so I can avoid time taken for pushing and pulling image from repository?
You may enter the container using bash if it installed on the image and modify it using -
docker exec -it <CONTAINERID> /bin/bash
However, this isn’t advisable solution. If your modifications succeed, you should update the Dockerfile accordingly or else you risk losing your work and ability to share it with others.
Have the container pull from git on creation?
Setup CI/CD?
Another way to achieve a similar result is to leave the application source outside of the container and mount the application source folder in the container.
This is especially useful when developing web applications in environments such as PHP: your container is setup with your Apache/PHP stack and /var/www/html is configured to mount your local filesystem.
If you are using minikube, it already mounts a host folder within the minikube VM. You can find the exact paths mounted, depending on your setup, here:
https://kubernetes.io/docs/getting-started-guides/minikube/#mounted-host-folders
Putting it all together, this is what a nginx deployment would look like on kubernetes, mounting a local folder containing the web site being displayed:
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx-deployment
spec:
selector:
matchLabels:
app: nginx
replicas: 1
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: nginx:1.7.9
ports:
- containerPort: 80
volumeMounts:
- mountPath: /var/www/html/
name: sources
readOnly: true
volumes:
- name: sources
hostPath:
path: /Users/<username>/<source_folder>
type: Directory
Finally we have resolved the issue. Here, we changed our image repository from docker hub to aws ecr in the same region where we are running kubernetes cluster. Now, it is taking very lesstime for pushing/pulling images.
This is definitely not recommended for production.
But if your intention is local development with kubernetes, take a look at these tools:
Telepresence
Telepresence is an open source tool that lets you run a single service
locally, while connecting that service to a remote Kubernetes cluster.
Kubectl warp
Warp is a kubectl plugin that allows you to execute your local code
directly in Kubernetes without slow image build process.
The kubectl warp command runs your command inside a container, the same
way as kubectl run does, but before executing the command, it
synchronizes all your files into the container.
I think it should be taken as process to create new images for each deployment.
Few benefits:
immutable images: no intervention in running instance this will ensure image run in any environment
rollback: if you encounter issues in new version, rollback to previous version
dependencies: new versions may have new dependencies
In my company we use GitLab as a source control and also use GitLab's Docker registry.
Each repository contains a Dockerfile for building an image and Kubernetes yaml's for defining the Pod/Service/Deployment/etc of that project.
The problem is that in the yaml's the image references the GitLab registry by its url
(Example from the Redis repository)
I don't like it for two reasons
It would make switching to another registry provider really hard since you'll have to go over your entire code base and change all the Kubernetes yaml files.
If a developer wants to test his app via minikube, he has to make sure that the image is stored and up to date in the registry. In our company, pushing to the registry is something that is done as part of the CI pipeline.
Is there a way to avoid storing the registry url in the repository?
Logging in to the docker registry beforehand doesn't solve it, you still have to provide the full image name with the url.
You can use an environment variable with shell scripts.
Here is the working example.
1) Create an environment variable
export IMAGE_URL=node:7-alpine
2) Create a 1 line shell script. This script purpose is replacing your env value in .yaml file with your actual environment variable.
echo sed 's/\$IMAGE_URL'"/$IMAGE_URL/g" > image_url.sh
3) Create sample yaml for example mypod.yaml.tmpl
cat > mypod.yaml.tmpl << EOL
apiVersion: v1
kind: Pod
metadata:
name: mypod
spec:
containers:
- name: mypod
image: $IMAGE_URL
# Just spin & wait forever
command: [ "/bin/ash", "-c", "--" ]
args: [ "while true; do sleep 30; done;" ]
EOL
4) Run kubectl apply
cat mypod.yaml.tmpl | sh image_url.sh | kubectl apply -f -