create custom self signed ECE certificates

generate_ece_cert.sh

export ELASTICSEARCH_IMG=docker.elastic.co/elasticsearch/elasticsearch:7.8.0
export DOMAIN="ece.internal"

docker run --rm -v "$(pwd)":/tmp/certs -w /tmp/certs $ELASTICSEARCH_IMG /usr/share/elasticsearch/bin/elasticsearch-certutil  ca \
  --pem \
  --out /tmp/certs/ca.zip

unzip ca.zip

docker run --rm -v "$(pwd)":/tmp/certs -w /tmp/certs $ELASTICSEARCH_IMG /usr/share/elasticsearch/bin/elasticsearch-certutil cert \
  --pem \
  --name server \
  --dns "${DOMAIN},*.${DOMAIN}" \
  --out /tmp/certs/server.zip \
  --ca-cert /tmp/certs/ca/ca.crt \
  --ca-key /tmp/certs/ca/ca.key

unzip server.zip

cat server/server.key server/server.crt ca/ca.crt > ece.cert.bundle