WEBVTT

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Hello and welcome to this lecture. In this lecture

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we will talk about various Logging mechanisms in kubernetes. Let us start with logging in Docker. I run

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a docker container called event-simulator and all that it does is generate random events simulating a web

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server.

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These are events streamed to the standard output by the application.

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Now, if I were to run the docker container in the background, in a detached mode using the –d option,

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I wouldn't see the logs if I wanted to view the logs.

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I could use the docker logs command followed by the container ID. The –f option helps us see the

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live log trail.

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Now back to Kubernetes. We create a pod with the same docker image using the pod definition file.

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Once it’s the pod is running, we can view the logs using the kubectl logs command with the pod name.

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Use the –f option to stream  the logs live just like the docker command.

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Now these logs are specific to the container running inside the pod.

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As we learned before, Kubernetes PODs can have multiple docker containers in them.

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In this case I modify my pod definition file to include an additional container called image-processor.

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If you ran the kubectl logs command

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now with the pod name, which container’s log would it show? If there are multiple containers within a

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pod.

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You must specify the name of the container explicitly in the command.

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Otherwise it would fail asking you to specify a name.

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In this case I will specify the name of the first container event-simulator and that prints the relevant

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log messages.

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Now, that is the simple logging functionality implemented within Kubernetes.

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And that is all that an application developer really needs to know to get started with Kubernetes.

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And that is all you really need to know as part of the certification program.

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However in the next lecture we will see more about some advanced logging configuration and third party

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support for logging in Kubernetes.

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We also have a nice demo that shows how a popular logging framework is integrated with kubernetes.

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Well that's it for this lecture.

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Head over to the coding exercises section and practice working with logs thank you.