A Technical I.T./DevOps Blog
Problem scenario
You want to configure the maximum number of Kubernetes readiness probe failures. How do you set this amount?
Solution
Use the failureThreshold setting.
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Continue reading “How Do You Configure the Kubernetes readiness Probe Max Failure Limit?”
Problem scenario
You want to back up many different emails from a web-based email. You cannot select several and print them all at once. What should you do?
Solution
Prerequisite
This assumes your web-based email can be configured to work with a desktop email client (such as Outlook).
Procedures
Install and configure Thunderbird, Outlook or an email client.
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Continue reading “How Do You Back Up Many Emails from a Web-based Email Quickly?”
Problem scenario
Your Kubernetes cluster is not working. The nodes are not ready. You see your Kubernetes nodes are not ready (with kubectl get nodes). You also see this error from a kubectl describe node foobar command:
runtime network not ready: NetworkReady=false reason:NetworkPluginNotReady message:docker: network plugin is not ready: cni config uninitialized
What should you do?
(If you get a different error, see this posting How Do You Troubleshoot a Kubernetes Cluster That is Not Working at the Node Level?
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Continue reading “How Do You Get Kubernetes Nodes to Be Ready?”
Problem scenario
You want to know what CNI plugin your Kubernetes cluster is using (e.g., Flannel, Calico, Weave Net, Romana or another one). What do you do?
Possible solution
“You can install only one Pod network per cluster.” taken from Kubernetes.io.
Go to a worker node and run these commands and look at the output:
ls -lh /etc/cni/net.d
ls -lh /opt/cni/bin | grep -i flannel
ls -lh /opt/cni/bin | grep -i calico
Use the sudo find / -name command to search for Romana or Weavenet vestiges.
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Problem scenario
You want to do some pre-testing on the .yaml file(s) you will use with kubectl. How do you validate a .yaml file has correct syntax for Kubernetes?
Possible Solution #1
Try this command:
kubectl apply –validate=true –dry-run=true –filename=nameofyourfile.yaml
Possible Solution #2
Try this website:
https://www.kubeyaml.com/
Possible Solution #3
Try kubeval: https://www.kubeval.com/
Possible Solution #4
Use Copper: http://copper.sh/
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Continue reading “How Do You Tell If the .yaml File for a kubectl Command Will Work?”
One of the following apply:
Problem scenario #1
You are using EKS and you have no config file in the .kube directory. You want to run some kubectl commands.
Problem scenario #2
You are using EKS and run a kubectl command, but you get this error: “The connection to the server localhost:8080 was refused – did you specify the right host or port?”
Solution
Run a command like this (but replace “us-west-1” with your region and replace “foobar” with the cluster_name):
aws eks –region us-west-1 update-kubeconfig –name foobar
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Continue reading “How Do You Create a .kube/config File with a “aws eks” Command?”
Problem scenario
You are running an aws ssm command. You receive a message about an error when parsing amazon-cloudwatch-agent.toml that also says ‘”/usr/share/collectd/types.db” no such file or directory’. What do you do?
Solution
Install collectd. If you are using a RedHat derivative of Linux (e.g., Fedora or CentOS), run this: sudo yum -y install collectd
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Problem scenario
Presto will not run because of an error about the JVM.
You get a message like this:
“Java version has an unknown format: 15” (from “C” below)
“Presto requires an Oracle or OpenJDK JVM (found Ubuntu)” (associated with the Java version shown in B or D below)
“Presto requires an Oracle or OpenJDK JVM (found Private Build)” (associated with the Java version in E below)
“Presto requires an Oracle or OpenJDK JVM (found IcedTea)” (associated with the Java version shown in F below)
Solution
For detailed background information,
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Problem scenario
You want to create EC-2 instances (nodes) for Kubernetes in AWS using EKS. You want to be able to connect to them or log into them for the sake of troubleshooting. You want to configure the Kubernetes nodes to use a .pem or .ppk file for SSHing into them. You analyzed the create node group documentation on the internet, but found a vague reference to a –remote-access flag and a ec2Sshkey pointing to a string.
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Continue reading “How Do You Create Nodes for EKS That Are Accessible to Log in?”
One of the following scenarios apply:
Problem scenario #1
You want to run a command like this:
aws iam put-role-policy –role-name contintdelete-role –policy-name DELETEPOLICY –policy-document file://adminPolicy.json
But you do not know the syntax of the adminPolicy.json.
Problem scenario #2
You are trying to use the –policy-document flag with the command “aws iam put-role-policy”. But you get this error:
An error occurred (MalformedPolicyDocument) when calling the PutRolePolicy operation: Syntax errors in policy.
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