Customising HTTP requests

.rsconnect_profile

When deploying content from the RStudio IDE, the rsconnect package’s deployment methods are executed in a vanilla R session that doesn’t execute startup scripts. This can make it challenging to ensure options are set properly prior to push-button deployment, so the rsconnect package has a parallel set of “startup” scripts it runs prior to deploying.

The following are run in order, if they exist, prior to deployment:

• $R_HOME/etc/rsconnect.site: Like Rprofile.site for site-wide pre-flight and options. This is typically used by system administrators.

• ~/.rsconnect_profile, like .Rprofile; this will affect all apps that you deploy.

• .rsconnect_profile, like .Rprofile; this will affect the current app. Unlike .Rprofile, if ~/.rsconnect_profile, is present, it will also be run.

HTTP Proxy Environment Variable

The most straightforward way to specify a proxy is to set the HTTPS_PROXY environment variable. For example, you could add the following code to your .rsconnect_profile:

Sys.setenv(https_proxy = "https://proxy.example.com")

Proxy settings can include a host-name, port, and username/password if necessary. The following are all valid values for the http_proxy environment variable:

• http://proxy.example.com/
• http://proxy.example.com:1080/
• http://username:[email protected]:1080/

Custom headers and cookies

If you need to supply additional headers or cookies, you can use the options rsconnect.http.headers and rsconnect.http.cookies respectively. rsconnect.http.headers needs a named vector of header names and values:

options(
  rsconnect.http.headers = c(
    "CustomHeader1" = "CustomValue", "CustomHeader2" = "CustomValue2"
  )
)

While rsconnect.http.cookies expects cookies formatted the same way that a webserver expects them:

options(
  rsconnect.http.headers = c("cookie1=value1", "cookie2=value2")
)

And you can supply other cookie parameters if needed:

options(
  rsconnect.http.headers = "cookie1=value1; Expires=Thu, 31 Oct 2021 07:28:00 GMT; Secure"
)

The custom headers are set first, so will be overridden by the headers that rsconnect needs to correctly operate. Similarly, cookies will be set prior to the first request, and will be overriden by anything returned by the server.

Other custom options

Finally, you can supply any additional options supported by curl::curl_options() with rsconnect.libcurl.options, e.g.

options(rsconnect.libcurl.options = list(proxy = "http://proxy.example.com")

Run curl::curl_options() to see a list of options.