Question
How would a DevOps engineer define operational readiness or what is operational readiness in I.T.?
Answer
“All things are ready, if our mind be so.” –William Shakespeare
While some people would say it is more of a state*, others may say it is more of a journey**. Operational readiness is having sufficient staff and automation to maintain the minimum level of service that the business requires for a given product or service.
Question
What is an Ingress resource in Kubernetes?
Answer
It is a Kubernetes technique of exposing services via an individual IP address (page 135 of Kubernetes in Action by Luksa). In TCP/IP networking, the Ingress port allows inbound traffic to route somewhere. Kubernetes supports other IP address to service mapping methods (e.g., NodePort or LoadBalancer). NodePort operates on layer 4 of the OSI seven-layer model (according to this posting).
Problem scenario
You want to run Splunk from a Docker container. What do you do?
Solution
Prerequisites
Install Docker. If you need assistance, see this posting.
Procedures
1. Run this command: docker pull splunk/splunk:latest
2. Run this command, but replace “simpleword” with the password that you want the administrator account for the web UI to have:
docker run -d -p 8000:8000 -e ‘SPLUNK_START_ARGS=–accept-license’ -e ‘SPLUNK_PASSWORD=simpleword’ splunk/splunk:latest
3.
Problem scenario
You want to know how dictionaries perform as iterables in Python. In Python for printing the values of every key-value pair in a dictionary, is it faster or slower than printing every item in a list? How does it compare to a tuple?
Solution
For this example we use integer keys in the dictionary. Keys can be strings or other objects.
Question
What is a deployment in Kubernetes?
Answer
A deployment is a resource that is designed for “deploying applications and updating them declaratively” (page 261 of Kubernetes in Action by Luksa). You may hear the phrase “Deployment controller.” As far as we know this is a reference to the process that runs in the Kubernetes Control Plane (page 262 of Kubernetes in Action by Luksa).
Problem scenario
You want to test out the Angular CLI on a Linux server. What should you do?
Solution
Prerequisite
Install node and npm. If you nsee assistance, see this posting How Do You Install node and npm on Any Distribution of Linux Server?.
Procedure
Run this command: sudo npm install -g @angular/cli
Question
In the context of computers, what is telemetry?
Answer
Telemetry in I.T. is the logged system data transmitted from other servers.
A more detailed definition of telemetry is the utilization of a centralized system to automatically ingest log data from other sources to enable one or more of the following: redundant storage of critical log data, monitoring, data visualization, anomaly detection,
Question
You have read about high/low level or higher-level (or lower-level) resources and constructs in the context of Kubernetes. What does this designation mean?
Answer
From a high level to a low level we may see a data center, filled with racks, which hold physical servers. Similarly from a high level to a low level we may see Kubernetes nodes supporting pods that have individual Docker containers.
Problem scenario
You are using Python 2.7.12 on Ubuntu 16. You want to upgrade to Python 3.x You are having problems. You tried several things as follows:
sudo apt-get -y install python 3.7
But you see this:
python is already the newest version (2.7.12-1~16.04).
python set to manually installed.
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
Problem scenario
You ran a Hadoop command but you receive this error:
Error: Could not create the Java Virtual Machine.
Error: A fatal exception has occurred. Program will exit.
What do you do?
Solution
Run hadoop help. This error can happen when you have an incorrect flag.