See here for a Hello World example using Codefresh.
Otherwise proceed to:
https://medium.com/containers-101/fully-automated-canary-deployments-in-kubernetes-70a671105273
This webinar also shows with / without Istio and using Helm for deployments: https://codefresh.io/webinars/istio-canary-deployment-with-helm-and-codefresh/
See
1. start local Kubernetes v1.10.0 cluster…
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minikube start --kubernetes-version v1.10.0 --memory 8192 --cpus 2 |
Errors:
If it hangs on:
Starting cluster components...
You can see what’s going on with:
minikube logs
which spits out thousands of lines of logs.
Annoyingly minikube logs -f does not work even though it’s implemented internally: https://github.com/kubernetes/dashboard/issues/1083
See Installing Kubernetes: Minikube for a solution.
2. helm init
3. Install Prometheus
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helm install \ --namespace=monitoring \ --name=prometheus \ --version=7.0.0 \ stable/prometheus |
which outputs
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NAME: prometheus LAST DEPLOYED: Thu Nov 1 13:22:45 2018 NAMESPACE: monitoring STATUS: DEPLOYED RESOURCES: ==> v1/PersistentVolumeClaim NAME AGE prometheus-alertmanager 1s prometheus-server 1s ==> v1beta1/ClusterRoleBinding prometheus-kube-state-metrics 1s prometheus-server 1s ==> v1beta1/DaemonSet prometheus-node-exporter 1s ==> v1/ConfigMap prometheus-alertmanager 1s prometheus-server 1s ==> v1/ServiceAccount prometheus-alertmanager 1s prometheus-kube-state-metrics 1s prometheus-node-exporter 1s prometheus-pushgateway 1s prometheus-server 1s ==> v1beta1/ClusterRole prometheus-kube-state-metrics 1s prometheus-server 1s ==> v1/Service prometheus-alertmanager 1s prometheus-kube-state-metrics 1s prometheus-node-exporter 1s prometheus-pushgateway 1s prometheus-server 1s ==> v1beta1/Deployment prometheus-alertmanager 1s prometheus-kube-state-metrics 1s prometheus-pushgateway 0s prometheus-server 0s ==> v1/Pod(related) NAME READY STATUS RESTARTS AGE prometheus-node-exporter-mfgcj 0/1 ContainerCreating 0 1s prometheus-alertmanager-99f6bfbcc-b8hkc 0/2 ContainerCreating 0 0s prometheus-kube-state-metrics-6584885ccf-fkkxc 0/1 ContainerCreating 0 0s prometheus-pushgateway-d5fdc4f5b-m7kzj 0/1 ContainerCreating 0 0s prometheus-server-86887bb56b-sjwhq 0/2 Pending 0 0s NOTES: The Prometheus server can be accessed via port 80 on the following DNS name from within your cluster: prometheus-server.monitoring.svc.cluster.local Get the Prometheus server URL by running these commands in the same shell: export POD_NAME=$(kubectl get pods --namespace monitoring -l "app=prometheus,component=server" -o jsonpath="{.items[0].metadata.name}") kubectl --namespace monitoring port-forward $POD_NAME 9090 The Prometheus alertmanager can be accessed via port 80 on the following DNS name from within your cluster: prometheus-alertmanager.monitoring.svc.cluster.local Get the Alertmanager URL by running these commands in the same shell: export POD_NAME=$(kubectl get pods --namespace monitoring -l "app=prometheus,component=alertmanager" -o jsonpath="{.items[0].metadata.name}") kubectl --namespace monitoring port-forward $POD_NAME 9093 The Prometheus PushGateway can be accessed via port 9091 on the following DNS name from within your cluster: prometheus-pushgateway.monitoring.svc.cluster.local Get the PushGateway URL by running these commands in the same shell: export POD_NAME=$(kubectl get pods --namespace monitoring -l "app=prometheus,component=pushgateway" -o jsonpath="{.items[0].metadata.name}") kubectl --namespace monitoring port-forward $POD_NAME 9091 For more information on running Prometheus, visit: https://prometheus.io/ |
Note: it mentions ContainerCreating – you can check on the current status with:
helm list
This shows you the state of the pod you’ve just created:
prometheus 1 Thu Nov 1 13:22:45 2018 DEPLOYED prometheus-7.0.0 2.3.2 monitoring
which had those 4 containers:
prometheus-node-exporter-mfgcj 0/1 ContainerCreating 0 1s prometheus-alertmanager-99f6bfbcc-b8hkc 0/2 ContainerCreating 0 0s prometheus-kube-state-metrics-6584885ccf-fkkxc 0/1 ContainerCreating 0 0s prometheus-pushgateway-d5fdc4f5b-m7kzj 0/1 ContainerCreating 0 0s prometheus-server-86887bb56b-sjwhq 0/2 Pending 0 0s
Source: https://github.com/ContainerSolutions/k8s-deployment-strategies
Charts describe a set of Kubernetes resources – e.g. a full web app stack with HTTP servers, databases, caches, etc.
requirements.yamldefines dependencies using:
Tags: like Ansible
Condition: enabled / disabled – always override tags.
See https://github.com/helm/helm/blob/master/docs/charts.md
Manage charts with helm:
Getting started with Helm:
1. check kubectl config – i.e. using local minikube
kubectl config view | grep current
2. start helm
helm init
Running helm install stable/mysql
(which uses: https://github.com/helm/charts/tree/master/stable/mysql )
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helm install stable/mysql NAME: queenly-seahorse LAST DEPLOYED: Mon Nov 5 11:22:13 2018 NAMESPACE: default STATUS: DEPLOYED RESOURCES: ==> v1/Secret NAME AGE queenly-seahorse-mysql 0s ==> v1/ConfigMap queenly-seahorse-mysql-test 0s ==> v1/PersistentVolumeClaim queenly-seahorse-mysql 0s ==> v1/Service queenly-seahorse-mysql 0s ==> v1beta1/Deployment queenly-seahorse-mysql 0s ==> v1/Pod(related) NAME READY STATUS RESTARTS AGE queenly-seahorse-mysql-6dc964999c-h4w54 0/1 Pending 0 0s NOTES: MySQL can be accessed via port 3306 on the following DNS name from within your cluster: queenly-seahorse-mysql.default.svc.cluster.local To get your root password run: MYSQL_ROOT_PASSWORD=$(kubectl get secret --namespace default queenly-seahorse-mysql -o jsonpath="{.data.mysql-root-password}" | base64 --decode; echo) To connect to your database: 1. Run an Ubuntu pod that you can use as a client: kubectl run -i --tty ubuntu --image=ubuntu:16.04 --restart=Never -- bash -il 2. Install the mysql client: $ apt-get update && apt-get install mysql-client -y 3. Connect using the mysql cli, then provide your password: $ mysql -h queenly-seahorse-mysql -p To connect to your database directly from outside the K8s cluster: MYSQL_HOST=127.0.0.1 MYSQL_PORT=3306 # Execute the following command to route the connection: kubectl port-forward svc/queenly-seahorse-mysql 3306 mysql -h ${MYSQL_HOST} -P${MYSQL_PORT} -u root -p${MYSQL_ROOT_PASSWORD} |
Let’s test we can connect to MySQL.
From the output, let’s get the MySQL password:
kubectl get secret --namespace default queenly-seahorse-mysql -o jsonpath="{.data.mysql-root-password}" | base64 --decode; echo
Copy.
Note: you could have got the pod name with:
kubectl get pods
Now exec into MySQL with:
kubectl exec -it queenly-seahorse-mysql-6dc964999c-h4w54 bash
Install MySQL client:
apt-get update && apt-get install mysql-client -y --force-yes
and connect with:
mysql -h localhost -p
More on:
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<span class="pl-s1">helm install --name my-release stable/wordpress</span> |
List with
helm list
and delete with
helm delete my-release
https://github.com/helm/charts/tree/master/stable/wordpress
Error: no available release name found
https://github.com/helm/helm/issues/3055
also
https://stackoverflow.com/questions/43499971/helm-error-no-available-release-name-found/43513182
Error: Get https://10.96.0.1:443/api/v1/namespaces/kube-system/configmaps?labelSelector=OWNER%!D(MISSING)TILLER: dial tcp 10.96.0.1:443: i/o timeout
When you do a helm list
From https://github.com/helm/helm/issues/3055#issuecomment-385371327
suggests
kubectl delete the tiller service and deployment.)
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$ kubectl create serviceaccount --namespace kube-system tiller $ kubectl create clusterrolebinding tiller-cluster-rule --clusterrole=cluster-admin --serviceaccount=kube-system:tiller $ helm init --service-account tiller |
So: kubectl delete tiller-deploy-6fd8d857bc-fp5s2
error: resource(s) were provided, but no name, label selector, or –all flag specified
kubectl list
Error: unknown command “list” for “kubectl”
This suggests deleting tiller using
helm reset
but this gives:
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helm reset Error: Get https://10.96.0.1:443/api/v1/namespaces/kube-system/configmaps?labelSelector=OWNER%!D(MISSING)TILLER: dial tcp 10.96.0.1:443: i/o timeout |
https://stackoverflow.com/questions/47583821/how-to-delete-tiller-from-kubernetes-cluster
and helm ls
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Error: Get https://10.96.0.1:443/api/v1/namespaces/kube-system/configmaps?labelSelector=OWNER%!D(MISSING)TILLER: dial tcp 10.96.0.1:443: i/o timeout |
Another, not very helpful, issue on why you can’t delete tiller:
https://github.com/helm/helm/issues/3536
Checking tiller:
kubectl get deploy -n kube-system
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NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE coredns 1 1 1 1 12d kube-dns 1 1 1 0 71d kubernetes-dashboard 1 1 1 0 71d tiller-deploy 1 1 1 1 8d |
To see pods in kube-system
kubectl get pods –namespace kube-system
e.g.
tiller-deploy-6fd8d857bc-fp5s2 1/1 Running 7 8d
Namespaces are for different environments. E.g. production, staging.
https://medium.com/@amimahloof/how-to-setup-helm-and-tiller-with-rbac-and-namespaces-34bf27f7d3c3
RBAC and Service Accounts:
https://docs.helm.sh/using_helm/#securing-your-helm-installation
Use ksonnet to generate Kubernetes configurations from Helm Charts
Install with brew install kubernetes-helm
https://github.com/helm/helm/blob/master/README.md
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helm init Creating /Users/snowcrash/.helm Creating /Users/snowcrash/.helm/repository Creating /Users/snowcrash/.helm/repository/cache Creating /Users/snowcrash/.helm/repository/local Creating /Users/snowcrash/.helm/plugins Creating /Users/snowcrash/.helm/starters Creating /Users/snowcrash/.helm/cache/archive Creating /Users/snowcrash/.helm/repository/repositories.yaml Adding stable repo with URL: https://kubernetes-charts.storage.googleapis.com Adding local repo with URL: http://127.0.0.1:8879/charts $HELM_HOME has been configured at /Users/snowcrash/.helm. Tiller (the Helm server-side component) has been installed into your Kubernetes Cluster. Please note: by default, Tiller is deployed with an insecure 'allow unauthenticated users' policy. To prevent this, run `helm init` with the --tiller-tls-verify flag. For more information on securing your installation see: https://docs.helm.sh/using_helm/#securing-your-helm-installation Happy Helming! |
Main concepts:
1. Chart: Helm package – contains all the resource definitions to run an application in a Kubernetes cluster.
See Helm Charts for examples of using Helm
2. Repository: where charts are stored
3. Release: an instance of a chart in a Kubernetes cluster. E.g. with a MySQL chart, you can have 2 databases running in a cluster by installing the chart twice. Each is its own release with its own release name.
Helm has two parts: the client (helm) and the server (tiller).
Tiller runs inside the Kubernetes cluster
Commands:
helm – outputs commands available
helm version – outputs client / server version.
helm init – runs helm.
helm init --upgrade– to upgrade Tiller.
Errors
Error: Get https://192.168.64.5:8443/api/v1/namespaces/kube-system/pods?labelSelector=app%3Dhelm%2Cname%3Dtiller: dial tcp 192.168.64.5:8443: connect: connection refused
it’s probably ‘cos you need to start Kubernetes. E.g. with minikube use:
minikube start
Error: could not find a ready tiller pod
if you run kubectl -n kube-system get po, check you see a tiller-deploy pod available there. Then, given the pod `tiller-deploy-6fd8d857bc-fp5s2
kubectl logs tiller-deploy-6fd8d857bc-fp5s2
Error from server (NotFound): pods "tiller-deploy-6fd8d857bc-fp5s2" not found
Solution to this is to use
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--namespace kube-system |
i.e.
kubectl logs --namespace kube-system tiller-deploy-6fd8d857bc-fp5s2
which says:
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[main] 2018/10/31 11:39:02 Starting Tiller v2.11.0 (tls=false) [main] 2018/10/31 11:39:02 GRPC listening on :44134 [main] 2018/10/31 11:39:02 Probes listening on :44135 [main] 2018/10/31 11:39:02 Storage driver is ConfigMap [main] 2018/10/31 11:39:02 Max history per release is 0 |
https://github.com/helm/helm/issues/2064
https://github.com/helm/helm/issues/2295
version is now working. But unsure if it was down to the earlier command I ran:
minikube addons enable registry-creds
Error: could not find tiller
Need to run helm init.
https://stackoverflow.com/questions/51646957/helm-could-not-find-tiller
For more on Helm Charts see: Helm Charts