A Technical I.T./DevOps Blog
Problem scenario
You have some JSON files like this:
$cat first.json
{“bird”: {“name”: “singy”, “species”: “sparrow”, “amount”: “45”}}
$ cat second.json
{“bird”: {“name”: “flighty”, “species”: “seagull”, “amount”: “21”}}
Within the “bird” key there are other keys. How do you create a tuple with the species values?
Solution
Place first.json, second.json and the Python program below (called reader.py) in the same directory.
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Problem scenario
The book Expert Python Programming (page 278) says 12 Factor app recommends that the application should not be aware of the format of the logs. JSON format for logs can be beneficial for various purposes. You want Nginx’s access logs — but not error logs — to be in JSON format. What do you do?
Solution
Use a file like this for your nginx.conf.
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Continue reading “How Do You Get Nginx Logs to be in JSON format?”
Problem scenario
You are not sure if you have valid JSON or not. You have converted raw logs of an application to be in JSON format. There is a flat file receiving what you believe to be valid JSON. How do you know for sure?
Solution
Put the JSON in here https://jsonformatter.curiousconcept.com/ and click “Process”.
The JSON should start with an opening brace { and end with a closing brace }.
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Continue reading “How Do You Know if Your Logging is Truly in JSON Format or Not?”
Problem scenario
You want to list the namespaces for a given user in Linux. You want the output to be in JSON. What should you do?
Solution
Run this command: lsns -J
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Continue reading “How Do You List Namespaces in Linux in JSON Format?”
Problem scenario
You want to run an Ansible playbook to push configuration changes down (e.g., transfer files to managed nodes). How do you do this?
Solution
Prerequisites
This assumes that you have set up Ansible. If you need directions for deploying an Ansible control server, see this posting. If you need directions for deploying a managed node after the central Ansible server has been set up,
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Problem scenario
How do you use the yum module in an Ansible playbook to install a yum package?
Solution
Prerequisites
This assumes you have installed Ansible and configured a managed node to work with it. If you need assistance with this, see this posting.
Procedures
1.
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Continue reading “How Do You Write an Ansible Playbook to Install a Yum Package?”
Problem scenario
You want to create a resource in a Kubernetes cluster. What should you do?
Solution
You should install Kubernetes. You will need a proper .yaml file in a directory on a server with kubectl installed and configured. You would then run a “kubectl create” command. See this posting for more information.
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Continue reading “How Do You Create a Resource in Kubernetes?”
Problem scenario
You want to use Helm to manage Kubernetes applications. Helm helps you with packages for changes to Kubernetes (in ways that are similar to yum or apt). Helm uses what are call Charts (.yaml files) that enable you to do more with Kubernetes with less trouble. Helm consists of these two things: a CLI tool and a server component that runs as a pod in a Kubernetes cluster (page 531 of Kubernetes in Action by Luksa).
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Continue reading “How Do You Know if You Have Helm Installed and what Version You Are Using?”
Problem scenario
The primary purposes of logging include troubleshooting (root cause analysis of poor performance, debugging unintended behavior, or resolving catastrophic failures). In some cases logging is used for monitoring of resource utilization and planning of changes. What patterns or characteristics of a good logging system (consistent with what some may phrase as “best practices”)?
Solution
Here are 13 traits of good logging.
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Continue reading “What Are the Recommended Practices of Logging?”
Problem scenario
You want to use Helm to manage Kubernetes applications. Helm helps you with packages for changes to Kubernetes (in ways that are similar to yum or apt). Helm uses what are call Charts (.yaml files) that enable you to do more with Kubernetes with less trouble. Helm consists of these two things: a CLI tool and a server component that runs as a pod in a Kubernetes cluster (page 531 of Kubernetes in Action by Luksa).
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