create multiple similar kubernetes deployments and services

deployment.yaml.in

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-$SHARD
spec:
  selector:
    matchLabels:
      app: nginx-$SHARD
  replicas: 250
  template:
    metadata:
      labels:
        app: nginx-$SHARD
    spec:
      containers:
      - name: nginx
        image: nginx:1.7.9
        ports:
        - containerPort: 80
        resources:
          requests:
            cpu: 10m

kubectl-create.sh

#!/bin/sh

# envsubst is in Debian package gettext-base 

set -e

SHARDS="a b c d e f g h i j"

export PORT=31000
export SHARD

rm -f deployments.yaml services.yaml

for SHARD in $SHARDS
do
  echo $SEPARATOR >> deployments.yaml
  echo $SEPARATOR >> services.yaml
  SEPARATOR="---"
  cat deployment.yaml.in | envsubst >> deployments.yaml
  cat service.yaml.in | envsubst >> services.yaml
  PORT=$(expr 1 + $PORT)
done

service.yaml.in

kind: Service
apiVersion: v1
metadata:
  name: service-$SHARD
spec:
  selector:
    app: nginx-$SHARD
  ports:
  - protocol: TCP
    port: 80
    nodePort: $PORT
    targetPort: 80
  type: NodePort