Monday, June 15, 2020

Seq - ERR_SSL_PROTOCOL_ERROR

Structured logging is the future and tools like ElasticSearch and Seq can help you manage and search through this structured log data.

While testing Seq, a colleague told me that he couldn’t access Seq. Instead his browser returned the following error:

ERR_SSL_PROTOCOL_ERROR

The problem was that he tried to access the Seq server using HTTPS although this was not activated. By default Seq runs as a windows service and listens only on HTTP.

To enable HTTPS some extra work needs to be done:

  • First make sure you have a valid SSL certificate installed in either the Local Machine or Personal certificate store of your Seq server.
  • Open the certificate manager on the server, browse to the certificate and read out the thumbprint value.
  • Now open a command prompt on the server and execute the following commands:
    • seq bind-ssl --thumbprint="THUMBPRINT HERE --port=9001
    • seq config -k api.listenUris -v https://YOURSERVER:9001
    • seq restart

Remark: The ‘--port’ parameter is only necessary when you are not listening on the standard HTTPS port(443).

More information: https://docs.datalust.co/docs/ssl