This is a Kubernetes deployment manifest written in YAML. It describes a deployment of a Tomcat container using the tomcat:8-alpine image.
Let’s go through it step by step:
- apiVersion: apps/v1 - This specifies the API version used for this deployment. In this case, it is version 1 of the apps API.
- kind: Deployment - This specifies the type of Kubernetes object being created. In this case, it is a Deployment.
- metadata: name - This specifies the name of the Deployment, which is “tomcat-deployment”.
- spec: replicas - This specifies that there should be one replica of the Tomcat container running.
- selector: matchLabels - This selects Pods with labels that match those specified in app: tomcatv1.
- template: metadata - This defines the Pod template that will be used to create new Pods when needed.
- labels: app - This sets the label for all Pods created by this template to “tomcatv1”.
- containers: name - This defines a single container named “tomcat” within each Pod created from this template.
- image - This specifies which Docker image should be used for this container (in this case, tomcat:8-alpine).
- volumeMounts - This mounts a volume named “tomcat-vm” at /usr/local/tomcat/conf within the container.
- ports - This exposes port 8080 within each container created from this template.
- volumes: name - This creates a volume named “tomcat-vm” that is backed by a ConfigMap named “tomcat-config”.
Overall, this manifest creates a single replica of a Tomcat container with its configuration stored in a ConfigMap and mounted as a volume. The pod created from this deployment listens on port 8080 for incoming traffic.
