# Bookstore — Part 02 ch.02 "Services": stable virtual IPs + DNS for every tier.
#
# A Pod IP is ephemeral; a Service is a STABLE name + ClusterIP that
# load-balances across the current Ready Pods selected by label. One
# ClusterIP Service per addressable tier. selectors are a SUBSET of each
# workload's pod template labels (verified against 10-/11-/12-/13-/14-/19-):
#   catalog         -> app: catalog         (10-catalog-deploy.yaml pods)
#   storefront      -> app: storefront      (11-storefront-deploy.yaml pods)
#   orders          -> app: orders          (14-orders-deploy.yaml pods)
#   redis           -> app: redis           (12-redis.yaml pods)
#   rabbitmq        -> app: rabbitmq        (13-rabbitmq.yaml pods)
#   payments-worker -> app: payments-worker (19-payments-worker-deploy pods)
#
# Part 06 ch.04 increment: a HEADLESS (clusterIP: None) Service for
# payments-worker. The worker has NO inbound request traffic — it is a queue
# consumer — so this Service exists ONLY to give Prometheus a stable set of
# scrape endpoints (the ServiceMonitor 80- selects it). clusterIP: None means
# no virtual IP / no kube-proxy load-balancing (there is nothing to balance);
# EndpointSlices still list every Ready Pod's IP, which is exactly what the
# Prometheus Operator turns into per-Pod scrape targets.
#
# `port` is the Service's stable port; `targetPort` is the container port it
# forwards to (here the NAMED port `http`/`redis`/`amqp`, so the container
# can move ports without touching the Service). No `type:` => ClusterIP
# (in-cluster only); external exposure is the Ingress (50-) / Gateway (51-).
#
# COEXISTENCE NOTE — the `catalog` Service:
#   30-catalog-canary.yaml ALSO defines a Service named `catalog` (the manual
#   canary teaching variant, Part 01 ch.08). This file defines the CANONICAL
#   `catalog` Service for the canonical Deployment (10-catalog-deploy.yaml).
#   Same name+namespace, and both select `app: catalog`, so they are
#   compatible (last-applied wins on a whole-dir apply; selector identical).
#   They pair with MUTUALLY EXCLUSIVE backends: run EITHER the canonical
#   catalog (10- + this) OR the canary stack (30-), never both (Part 01 ch.08
#   lineage note). A whole-dir dry-run is valid either way.
#
# Requires (the workloads these select):
#   kubectl apply -f examples/bookstore/raw-manifests/00-namespace.yaml
#   kubectl apply -f examples/bookstore/raw-manifests/10-catalog-deploy.yaml
#   kubectl apply -f examples/bookstore/raw-manifests/11-storefront-deploy.yaml
#   kubectl apply -f examples/bookstore/raw-manifests/12-redis.yaml
#   kubectl apply -f examples/bookstore/raw-manifests/13-rabbitmq.yaml
#   kubectl apply -f examples/bookstore/raw-manifests/14-orders-deploy.yaml
# Apply:
#   kubectl apply -f examples/bookstore/raw-manifests/40-services.yaml
#   kubectl get svc,endpointslices -n bookstore
apiVersion: v1
kind: Service
metadata:
  name: catalog
  namespace: bookstore
  labels:
    app: catalog
    app.kubernetes.io/part-of: bookstore
spec:
  type: ClusterIP                   # default: in-cluster virtual IP only
  selector:
    app: catalog                    # subset of 10-catalog-deploy pod labels
  ports:
    - name: http
      port: 80                      # stable Service port (catalog.bookstore:80)
      targetPort: http              # -> container's named port 8080
---
apiVersion: v1
kind: Service
metadata:
  name: storefront
  namespace: bookstore
  labels:
    app: storefront
    app.kubernetes.io/part-of: bookstore
spec:
  type: ClusterIP
  selector:
    app: storefront                 # subset of 11-storefront-deploy pod labels
  ports:
    - name: http
      port: 80
      targetPort: http              # -> container's named port 8080
---
apiVersion: v1
kind: Service
metadata:
  name: orders
  namespace: bookstore
  labels:
    app: orders
    app.kubernetes.io/part-of: bookstore
spec:
  type: ClusterIP
  selector:
    app: orders                     # subset of 14-orders-deploy pod labels
  ports:
    - name: http
      port: 80
      targetPort: http              # -> container's named port 8080
---
apiVersion: v1
kind: Service
metadata:
  name: redis
  namespace: bookstore
  labels:
    app: redis
    app.kubernetes.io/part-of: bookstore
spec:
  type: ClusterIP
  selector:
    app: redis                      # subset of 12-redis pod labels
  ports:
    - name: redis
      port: 6379
      targetPort: redis             # -> container's named port 6379
---
apiVersion: v1
kind: Service
metadata:
  name: rabbitmq
  namespace: bookstore
  labels:
    app: rabbitmq
    app.kubernetes.io/part-of: bookstore
spec:
  type: ClusterIP
  selector:
    app: rabbitmq                   # subset of 13-rabbitmq pod labels
  ports:
    - name: amqp
      port: 5672
      targetPort: amqp              # -> container's named port 5672
    - name: management
      port: 15672
      targetPort: management        # mgmt UI (port-forward target in hands-on)
---
# Part 06 ch.04: HEADLESS metrics-only Service for payments-worker (19-).
# clusterIP: None — the worker is a RabbitMQ consumer with NO inbound request
# traffic, so there is nothing to virtual-IP / load-balance. The Service
# exists purely so the Prometheus Operator's ServiceMonitor (80-) has a
# selectable Endpoints/EndpointSlice object listing each worker Pod's
# :8080 /metrics. selector is a subset of 19-'s pod labels.
apiVersion: v1
kind: Service
metadata:
  name: payments-worker
  namespace: bookstore
  labels:
    app: payments-worker
    app.kubernetes.io/part-of: bookstore
spec:
  clusterIP: None                   # headless: no VIP, no kube-proxy LB
  selector:
    app: payments-worker            # subset of 19-payments-worker-deploy pod labels
  ports:
    - name: metrics
      port: 8080
      targetPort: metrics           # -> container's named port 8080 (/metrics)