On Wednesday, March 1, the RDA website will change to serving all content and services over secure HTTP. The are multiple benefits to doing this and if you want to learn more, do a web search for "HTTP Everywhere" or "Securing the Web", for example.
For most users, this change will be barely noticeable. When you request an insecure URL (e.g. - http://rda.ucar.edu), your browser will receive a redirect message, and then the browser will initiate a new connection over HTTPS. You will see a padlock in the URL bar and the URL will begin with https, but otherwise all content will be the same and all services will perform as they currently do.
The RDA web server will also enable HTTP Strict Transport Security (HSTS) by sending an HSTS header message that tells your browser to only connect over secure HTTP in the future. If you have an HSTS-aware browser, then even if you type http://rda.ucar.edu into the URL bar, the browser will convert it to https://rda.ucar.edu for you before initiating the connection.
The main impact will be to users who are downloading data files via scripts that use curl. We have found that curl does not automatically follow a redirect - that will only happen if the "-L" flag is included with the curl command. Without the "-L" flag, users requesting a data file over http will receive a file that doesn't actually contain data - it will contain HTML that explains that the file has moved permanently. For curl scripts generated by the RDA server, we will begin including the "-L" flag as well as writing URLs beginning with https. If you have an older script generated by our server, or you have written your own script using curl, you will need to make the change yourself. We have found that wget (at least newer versions of it) will automatically follow the redirect.
If you run into any trouble after the change-over, please let us know right away at firstname.lastname@example.org.
UPDATE (Mar 15): We discovered another issue - POST requests, even if the client follows the redirect, will not work because they get resubmitted as GET requests. This issue will affect both curl and wget. You will need to change URLs to https to get around this problem.