Internal GitHub downloader doesn't configure proxy

[mmarchetti]

We saw this issue in a Connect customer environment.

They have a proxy for internet access. http_proxy and https_proxy environment variables are set when packrat is invoked. Packrat has no trouble installing packages from CRAN.

What we saw is:

• Connect configures download.file.method to be curl, and sets some curl options.
• Packrat, with devtools and httr installed, uses its internal GitHub downloader which uses httr.
• The internal downloader doesn't configure httr's proxy settings based on http_proxy and https_proxy.
• Consequently, package downloads from GitHub failed.

Some ideas for fixes include always using the configured downloader, or configuring httr's proxy settings based on the standard proxy environment variables.

[mmarchetti]

We worked around this by removing devtools from the R installations being used in Connect.

[kevinushey]

See also:

packrat/R/github.R

Lines 9 to 25 in 6dd9d59

	githubDownload <- function(url, destfile, ...) {
	onError(1, {
	github_pat <- yoink("devtools", "github_pat")
	authenticate <- yoink("httr", "authenticate")
	GET <- yoink("httr", "GET")
	content <- yoink("httr", "content")
	token <- github_pat(quiet = TRUE)
	auth <- if (!is.null(token))
	authenticate(token, "x-oauth-basic", "basic")
	else
	list()
	request <- GET(url, auth)
	writeBin(content(request, "raw"), destfile)
	if (file.exists(destfile)) 0 else 1
	})
	}

packrat/R/gitlab.R

Lines 9 to 11 in 6dd9d59

	gitlabDownload <- function(url, destfile, ...) {
	onError(1, gitlabDownloadImpl(url, destfile, ...))
	}

We could provide some mechanism for overriding the default Packrat behaviors here.