Illegal Base64 Data Error When Exporting Logs from Fluentd

Issue

• We currently have Openshift's EFK (logging) stack running, and are trying to configure the internal fluentd to send logs to an external fluentd process
• The certificate and key that we've obtained were generated from the command:

# openssl genrsa -des3 -out fluentca.key 4096
# openssl req -newkey rsa:2048 -nodes -keyout fluentca.key -x509 -out fluentca.crt

• The documentation mentions patching the logging-fluentd secrets using the oc patch command. We attempted to run the first one for the certificate using the keys generated above as follows:

# oc patch secrets/logging-fluentd --type=json \
  --patch "[{'op':'add','path':'/data/fluentca.crt','value':'$(base64 /etc/fluent/keys/fluentca.crt)'}]"

But we get the error:

Error from server: [pos 7039]: json: error decoding base64 binary '---long-key-string-snipped---': illegal base64 data at input byte 76