credential_helpers: Helpers for supplying SMTP credentials

Description

These helper functions, the credential helpers, are used to supply SMTP configuration and authorization information for the smtp_send() function. The creds_file(), creds_anonymous(), creds_key(), and creds() functions are to be used expressly with the credentials argument of smtp_send().

Usage

creds(user = NULL, provider = NULL, host = NULL, port = NULL, use_ssl = TRUE)
creds_anonymous(provider = NULL, host = NULL, port = NULL, use_ssl = TRUE)
creds_envvar(
  user = NULL,
  pass_envvar = "SMTP_PASSWORD",
  provider = NULL,
  host = NULL,
  port = NULL,
  use_ssl = TRUE
)
creds_key(id)
creds_file(file)

Value

A credentials list object.

Arguments

user: The username for the email account. Typically, this is the email address associated with the account.
provider: An optional email provider shortname for autocompleting SMTP configuration details (the host, port, use_ssl options). Options currently include gmail, outlook, and office365. If nothing is provided then values for host, port, and use_ssl are expected.
host, port, use_ssl: Configuration info for the SMTP server. The host and port parameters are the address and port for the SMTP server; use_ssl is an option as to whether to use SSL: supply a TRUE or FALSE value.
pass_envvar: The name of the environment variable that holds the value for an email account password. This is only used in the creds_envvar() credential helper function.
id: When using the creds_key() credential helper, the ID value of the key (in the system key-value store) needs to be given here. This was explicitly provided when using the create_smtp_creds_key() function (with its own id argument). To get an information table with all available blastula keys in the key-value store, we can use the view_credential_keys() function.
file: When using the creds_file() credential helper, we need to specify the location of the credential file, and, this is where that is done. The credential file was ideally generated by the create_smtp_creds_file() function.

Details

The creds() credential helper allows for manual specification of SMTP configuration and authentication.

The creds_anonymous() credential helper is similar to creds() but provides convenient defaults for authenticating anonymously with an SMTP server.

The creds_key() credential helper gets credentials stored in the system-wide key-value store. We can set that key and the credentials data using the create_smtp_creds_key() function.

The creds_file() credential helper is used to obtain credentials from a file stored on disk. We can create that file using the create_smtp_creds_file() function.

The creds_envvar() credential helper reads the password from the SMTP_PASSWORD environment variable (or an environment variable name that you specify). If using environment variables for other parameters, call Sys.getenv() manually (e.g. user = Sys.getenv("SMTP_USER")).