Configure a connection to an HTC submit server

htc_config() creates or reads an htc.cfg file that stores the connection details needed by htc_stage(), htc_submit(), htc_status(), and htc_fetch_results(). On first use it prompts interactively for your username and server address, writes htc.cfg to path, and adds it to .gitignore. Subsequent calls read the existing file.

Usage

htc_config(username = NULL, server = NULL, path = ".", overwrite = FALSE)

Arguments

username: A character string. Your HTC username (NetID), e.g. "erwin.lares". If NULL and no htc.cfg exists, the function prompts interactively.
server: A character string. The HTC submit server hostname. Defaults to "ap2002.chtc.wisc.edu". If NULL and no htc.cfg exists, the function prompts interactively.
path: A character string. Directory where htc.cfg will be read from or written to. Defaults to "." (current working directory).
overwrite: Logical. If TRUE, recreates htc.cfg even if one already exists. Defaults to FALSE.

Value

A named list with elements username and server, returned invisibly.

SSH connection reuse

Each call to htc_stage(), htc_submit(), htc_status(), or htc_fetch_results() opens a new SSH connection to the submit server, which triggers a Duo MFA prompt each time. You can avoid this by configuring SSH connection reuse (ControlMaster) in your ~/.ssh/config file. Add the following block:

Host *.chtc.wisc.edu
  ControlMaster auto
  ControlPersist 2h
  ControlPath ~/.ssh/connections/%r@%h:%p

Then create the connections directory:

mkdir -p ~/.ssh/connections

After this, only the first connection in a two-hour window will require Duo authentication. Full documentation: https://chtc.cs.wisc.edu/uw-research-computing/configure-ssh

Security

htc.cfg contains your username and server address. Neither is sensitive on its own, but htc_config() adds htc.cfg to .gitignore on creation to avoid accidentally committing institutional account details to a public repository.

Examples

# \donttest{
# Preview what htc_config() would return without writing any files
cfg <- list(username = "netid", server = "ap2002.chtc.wisc.edu")
str(cfg)
#> List of 2
#>  $ username: chr "netid"
#>  $ server  : chr "ap2002.chtc.wisc.edu"
# }

if (FALSE) { # \dontrun{
# Interactive first-time setup
cfg <- htc_config()

# Non-interactive setup (for scripts)
cfg <- htc_config(
  username = "erwin.lares",
  server   = "ap2002.chtc.wisc.edu"
)

# Force recreation of htc.cfg
cfg <- htc_config(overwrite = TRUE)

# Use in other functions
htc_upload(files = c("job.sub", "job.sh"), config = cfg)
} # }