- Practice with docker engine
- Understand the most important instructions used in a dockerfile
- Know hot to build a container image from a dockerfile
- Learn how to save a container image to a file and how to load a container
from a file
- Practice command for creating, edit, inspecting and interacting with a Pod
k run allows for fast creation of pod- Understand diff life cycles to be able to quickly diagnose error conditions
- The actual job is executed in pods.
- Understand the different operational types (parallel, completion) for jobs
can be tricky.
- Force yourself into setting up all possible scenarios and inspect their
runtime behaviour.
- Know how to configure and inspect the retained job history.
- Understand different use cases for wanting to use ephemeral or persistent.
- Practice the most common volume types. (
emptyDir, hostPath).
- Go to the process of dynamic and static binding.
- static, you need to create the pv
- dynamic, automatically created the pv
- The attributes that can be assigned to an
initContainers section are the
same as the containers section
- Design patterns (Sidecar, Ambassador, etc). When to use and how to implement.
- Some primitives, Deployment, Service and Network Policy, use label selection
heavily.
- Annotations are not made for querying, some reserved annotations may
influence runtime behaviour.
- When creating a deployment make sure label selection match with the pod
template.
- Practice how to scale the number of replicas manually
--replicas or via
hpa for thresholds.
- be aware of the
k rollout undo.
- know how to apply the deployment strategies.
- Just know that helm is an open source tool for installing a set of
yaml
manifests.
- Practice discovering and installing existing charts, using the helm
executable.
kubectl will show a message if an api will be deprecated- Check the migration guide
- Understand the purpose of readiness, startup and liveness probes.
- Easy to just copy-paste the k8s docs
- Try to induce failure conditions to see the runtime effects
- You wont have to install the metric server
- Understand the purpose of the metric server, and which other objects use it.
- practice relevant
k command to diagnose issues.
- proactively expose yourself to failing pods
- You are not expected to implement a CRD schema.
- You only need to know how to discover them and use them.
- To study, you can install an open source CRD
- RBAC defines permissions for permitted operations on specific API resources
- Role and RoleBinding define permissions for objects in a namespace.
- ClusterRole and ClusterRoleBinding define permissions for objects across
all namespaces.
- We can use the ServiceAccount object to run services against the k8s
cluster itself. It will auth with RBAC also.
- 3 aspects,
- how to define min and max resources for a container.
- resource quota to limit the aggregate resource consumption or limit the
overall objects created in a namespace
- limit range, constrains of defaults the resources alloc for an specific
object type.
- Understand the purpose for a configmap against a secret
- Secrets are meant to represent sensitive data. They are not encrypted
- How to define those configmaps and secret objects. How to interact with them.
- The security context lest you provide privilege and access control to
containers.
- You can define it to the whole pod or to individual containers.
- Know where to find the security attributes. (k8s docs)