import RDS certificates to java keystore on alpine / osx

import-rds-certs.sh

#!/bin/zsh
set -euo pipefail
IFS=$'\n\t'

# i tried it and working like charm just have to note make the file .sh chmod +x and you may need sudo to run with permission but be carefull with sudo
# be sure the $JAVA_HOME is configure correctly or make it static as commentedline 7 below
OLDDIR="${PWD}"
CACERTS_FILE=$(/usr/libexec/java_home -v 1.8)/jre/lib/security/cacerts

mkdir /tmp/rds-ca && cd /tmp/rds-ca

echo "Downloading RDS certificates..."

curl https://s3.amazonaws.com/rds-downloads/rds-combined-ca-bundle.pem > rds-combined-ca-bundle.pem

csplit -sk rds-combined-ca-bundle.pem "/-BEGIN CERTIFICATE-/" "{$(grep -c 'BEGIN CERTIFICATE' rds-combined-ca-bundle.pem | awk '{print $1 - 2}')}"

for CERT in xx*; do
    # extract a human-readable alias from the cert
    ALIAS=$(openssl x509 -noout -text -in "${CERT}" |
                   perl -ne 'next unless /Subject:/; s/.*CN=//; print')
    echo "importing ${ALIAS}"
    # delete existing
#    keytool -delete -alias "${ALIAS}" \
#            -keystore  "${CACERTS_FILE}" \
#            -storepass changeit -noprompt
    # import the cert into the default java keystore
    keytool -import \
            -keystore  "${CACERTS_FILE}" \
            -storepass changeit -noprompt \
            -alias "${ALIAS}" -file "${CERT}"
done

cd "${OLDDIR}"

rm -r /tmp/rds-ca