Resolve "Include scripts to create client certificates in docker image"

Related to #35 (closed)

docker/certmanager/create-ca.sh

 #!/bin/bash
+# Caciano Machado/Juliano Zatta - 16/10/2017
 
 cd /certmanager
 
 . config
-openssl genpkey -algorithm RSA -out certificates/rootCA.key -pkeyopt rsa_keygen_bits:2048
-openssl req -x509 -new -nodes -key certificates/rootCA.key -sha256 -days 3650 -out certificates/rootCA.pem -subj "/C=BR/ST=$STATE/L=$CITY/O=$ORG/OU=$UNIT/CN=$HOST" -set_serial "0x$(openssl rand -hex 8)"
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+
+cd certificates
+
+if [ -a ${CERTNAME}.pem ]; then
+    echo "WARNING: Certificate with name $CERTNAME already exists."
+    echo "WARNING: If you really want to delete it then do it manually."
+else
+    ROOTCA_SERIAL=`openssl rand -hex 8`
+    openssl genrsa -out ${CERTNAME}.key $KEYSIZE
+    openssl req  -subj "/C=BR/ST=$STATE/L=$CITY/O=$ORG/OU=$UNIT/CN=Root\ Certificate" -x509 -new -nodes -key ${CERTNAME}.key -sha256 -days $ROOTEXP -out ${CERTNAME}.pem -set_serial "0x$ROOTCA_SERIAL"
+    echo $ROOTCA_SERIAL > rootCA.srl
+fi
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