R/AWSRootCredentials.R

In AlonzoBarnett/RcurlAWS: Interface for R to AWS focused on credential management and generic API requests.

#'@title getCredentials
#'@description Worker function to find credentials in multiple search locations.
#'@param AWS_ACCESS_KEY_ID Your AWS root account access id
#'@param AWS_SECRET_ACCESS_KEY Your AWS root account secret key
#'@param sourceFile Location of credentials file ex. ~/.aws/.credential
#'@param profileName Name of the profile you wish to invoke
#'    'defualt' is used unless otherwise explicitly declared
#'@param .silent Doesn't do anything but is reserved to warning suppression or verbosity setting
#'
#'@details
#'The initializer function of AWSRootCredentials object.
#'@family credential management functions
#'
getCredentials <- function(
    AWS_ACCESS_KEY_ID = NULL,
    AWS_SECRET_ACCESS_KEY = NULL,
    profileName = NULL, #"default"
    credentialPrefix = NULL,
    credentialFileName = NULL,
    configFileName = NULL
) {
    
    #If explicit credentials passed, just use those.
    if (!is.null(AWS_ACCESS_KEY_ID) & !is.null(AWS_SECRET_ACCESS_KEY)) {
        self$AWS_ACCESS_KEY_ID <- AWS_ACCESS_KEY_ID
        self$AWS_SECRET_ACCESS_KEY <- AWS_SECRET_ACCESS_KEY
        return(NULL)
    }
    
    #If Profile provided, look for it...
    if (!is.null(profileName)) {
        awsProfiles <- getProfiles(credentialPrefix, credentialFileName, configFileName, profileName)
        if (is.null(awsProfiles)){
            stop(sprintf('Profile %s not found.'), profileName)
        }
        self$profile <- profileName
        self$profileSettings <- awsProfiles[[profileName]]
        self$AWS_ACCESS_KEY_ID <- awsProfiles[[profileName]][['AWS_ACCESS_KEY_ID']]
        self$AWS_SECRET_ACCESS_KEY <- awsProfiles[[profileName]][['AWS_SECRET_ACCESS_KEY']]
        return(NULL)
    }
    
    #If no arg so far, try env.
    creds <- Sys.getenv(x = c("AWS_ACCESS_KEY_ID", "AWS_SECRET_ACCESS_KEY"))
    if (any(creds == "")) {
        creds <- NULL
    }else{
        self$AWS_ACCESS_KEY_ID <- creds$AWS_ACCESS_KEY_ID
        self$AWS_SECRET_ACCESS_KEY <- creds$AWS_SECRET_ACCESS_KEY
        return(NULL)
    }
    
    #Finally, nothing passed and no env hit, so try default profile lookup.
    profileName <- 'default'
    awsProfiles <- getProfiles(credentialPrefix, credentialFileName, configFileName, profileName)
    if (is.null(awsProfiles)){
        stop('Credential search failed and no default profile found.')
    }
    
    self$profile <- profileName
    self$profileSettings <- awsProfiles[[profileName]]
    self$AWS_ACCESS_KEY_ID <- awsProfiles[[profileName]][['AWS_ACCESS_KEY_ID']]
    self$AWS_SECRET_ACCESS_KEY <- awsProfiles[[profileName]][['AWS_SECRET_ACCESS_KEY']]
    return(NULL)
}

#'@title AWS Root Credential Manager
#'@description R6 implementation of AWS Root credential searches and management
#'
#'\code{AWSRootCredentials$new(AWS_ACCESS_KEY_ID = NULL,
#'                           AWS_SECRET_ACCESS_KEY = NULL,
#'                           sourceFile = NULL,
#'                           profileName = "default",
#'                           .silent = T)
#'}
#'
#'\code{AWSRootCredentials$print()}
#'
#'@param AWS_ACCESS_KEY_ID Your AWS root account access id
#'@param AWS_SECRET_ACCESS_KEY Your AWS root account secret key
#'@param sourceFile Location of credentials file ex. ~/.aws/.credential
#'@param profileName Name of the profile you wish to invoke
#'    'defualt' is used unless otherwise explicitly declared
#'
#'@details
#' On initialization if you pass an access and secret key,  
#'     the search is skipped and the keys you passed are used.  
#'     Print method, prints only *s to protect your keys.  
#'  
#' You can use $ to force print of an attribute if you really want to have
#'     it hanging around on your screen.
#'  
#' If no arguments are provided, credential priority... not search order
#'     but what will be returned if found... is loosely based on typical SDK fashion:
#'       \enumerate{
#'           \item Environment variables "AWS_ACCESS_KEY_ID", "AWS_SECRET_ACCESS_KEY"
#'           \item Credentials file
#'       }
#'  
#' It is assumed your credentials file follows the guidelines at:  
#'     \url{https://docs.aws.amazon.com/cli/latest/userguide/cli-config-files.html}{AWS CLI Configuration and Credential Files}  
#'  
#' If you have multiple profiles in the credentials file,  
#'     a profile labeled "default" will be searched for UNLESS you explicitly  
#'     declare the profile name to return.  
#'
#' \strong{Differences from SDK Implementations}  
#'     \enumerate{
#'       \item If Credentials file pointed to explicitly, then this is the only location checked. This is a more intuative behavior; if I tell you where to look, don't give me results from some other location.
#'       \item Instance MetaData is not searched; this is done with AWSTemporaryCredentials$new().
#' }
#'
#' AWSRootCredentials are a simpler class of credentials (only access and secret keys are necessary.  
#' AWSTemporaryCredentials, which are Role based, are generated by STS.  
#' I opted to treat root and temporary credentials as distinct class references. This seems less confusing for an end-user then trying to track what will be returned by a single class when referencing the two different credential sources.
#'
#'@family credential management functions
#'@examples
#Will try to find credentials if you don't provide any information.
#'\dontrun{rootCreds <- AWSRootCredentials$new()}
#Is probably best to tell it where to look.
#
#Windows ex:
#'\dontrun{rootCreds <- AWSRootCredentials$new(credentialPrefix = "/i/hide/my/files")}
#'Provide filenames if not using 'config' & 'credentials'
#'\dontrun{rootCreds <- AWSRootCredentials$new(
#'    credentialPrefix = "/i/hide/my/files")}
#'    credentialFileName = 'myCreds',
#'    configFileName = 'myConfig'
#')
#Explicitly pass access and secret:
#'\dontrun{rootCreds <- AWSRootCredentials$new(AWS_ACCESS_KEY_ID = "blahblah", AWS_SECRET_ACCESS_KEY = "blahblah")}
#Print method obscures your access and secret for safety
#'\dontrun{rootCreds}
#You can force print if you really want ...
#'\dontrun{rootCreds$AWS_ACCESS_KEY_ID}
#'\dontrun{rootCreds$AWS_SECRET_ACCESS_KEY}
#The 'profileSettings' attribute containes the combination of credentials & config for the profile discovered.
#'rootCreds$profileSettings
#'
#' @export
AWSRootCredentials <- R6::R6Class(
    "AWSRootCredentials",
    public = list(
        profile = NULL,
        profileSettings = NULL,
        AWS_ACCESS_KEY_ID = NULL,
        AWS_SECRET_ACCESS_KEY = NULL,
        initialize = getCredentials,
        print = function(...) {
            cat(
                "<AWSRootCredentials>\n\tAWS_ACCESS_KEY_ID = ",
                paste(rep("*", nchar(self$AWS_ACCESS_KEY_ID)), collapse = ""),
                "\n\tAWS_SECRET_ACCESS_KEY = ",
                paste(rep("*", nchar(self$AWS_SECRET_ACCESS_KEY)), collapse = ""),
                "\n",
                sep = ""
            )
            invisible(self)
        }
    )
)