version 0.1.4

DESCRIPTION

@@ -1,8 +1,8 @@
 Package: aws.ec2metadata
 Type: Package
 Title: Get EC2 Instance Metadata
-Version: 0.1.2
-Date: 2017-06-29
+Version: 0.1.4
+Date: 2018-04-02
 Authors@R: c(person("Thomas J.", "Leeper", role = c("aut", "cre"),
                     email = "thosjleeper@gmail.com"))
 Description: Retrieve Amazon EC2 instance metadata from within the running instance.
@@ -12,8 +12,8 @@ BugReports: https://github.com/cloudyr/aws.ec2metadata/issues
 Imports: curl, jsonlite
 RoxygenNote: 6.0.1
 NeedsCompilation: no
-Packaged: 2017-06-30 14:49:15 UTC; THOMAS
+Packaged: 2018-04-02 21:28:34 UTC; THOMAS
 Author: Thomas J. Leeper [aut, cre]
 Maintainer: Thomas J. Leeper <thosjleeper@gmail.com>
 Repository: CRAN
-Date/Publication: 2017-06-30 17:19:40 UTC
+Date/Publication: 2018-04-03 07:45:54 UTC

MD5

@@ -1,7 +1,8 @@
-405fa5c4d5831b9e3f1c074985a9ada2 *DESCRIPTION
-0cc685d45f8c103eebeeaa5d1e4d38de *NAMESPACE
-41471f25499eda464b3689dd9031e1b4 *NEWS.md
-3b050e4089b783294477b8b411afcbd5 *R/aws.ec2metadata-package.R
+89967f5aaff82da28c57cc10611f4a04 *DESCRIPTION
+f7dbef91aec243ba9698c68a0b3d50ea *NAMESPACE
+a49099f9da864516507033d50558ca58 *NEWS.md
+d041ec247bb6db1602649aeca1bca2d0 *R/aws.ec2metadata-package.R
+58bf6f90e895e7155df5e50c99bba326 *R/onLoad.R
 d4e152223ef91d1cb33445013f7c03ef *README.md
 eab6c62029e39bae5d6faa9981a8d2d5 *inst/CITATION
-6ad437f305e7b8be192c797eab30b042 *man/ec2metadata.Rd
+1ab2168f083054ef4f57c4a68bd1ca82 *man/ec2metadata.Rd

NAMESPACE

@@ -1,5 +1,6 @@
 # Generated by roxygen2: do not edit by hand
 
+export(instance_document)
 export(is_ec2)
 export(metadata)
 importFrom(curl,curl_fetch_memory)

NEWS.md

@@ -1,7 +1,16 @@
-# CHANGES TO aws.ec2metadata 0.1.2
+# aws.ec2metadata 0.1.4
+
+* Previous `.onLoad()` functionality added in 0.1.3 is now moved to `.onAttach()` to comply with CRAN policy.
+
+# aws.ec2metadata 0.1.3
+
+* Added a function `instance_document()` that returns a list of the ["instance identity document"](http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/instance-identity-documents.html) information. This is useful for identifying the region an instance is running in.
+* When the package is loaded on an EC2 instance (as identified by `is_ec2()` during package load), the package attempts to set the `AWS_DEFAULT_REGION` environment variable if it has not already been specified. This helps handle request signing.
+
+# aws.ec2metadata 0.1.2
 
 * Added a function `is_ec2()` that returns a logical based on whether metadata is retrievable.
 
-# CHANGES TO aws.ec2metadata 0.1.1
+# aws.ec2metadata 0.1.1
 
 * Initial release.

R/aws.ec2metadata-package.R

@@ -47,19 +47,30 @@ is_ec2 <- function() {
     }
 }
 
+#' @rdname ec2metadata
+#' @importFrom jsonlite fromJSON
+#' @export
+instance_document <- function() {
+    jsonlite::fromJSON(get_instance_metadata(item = "dynamic/instance-identity/document"))
+}
+
 #' @rdname ec2metadata
 #' @details \code{is_ec2} returns a logical for whether the current R session appears to be running in an EC2 instance.
 #' 
+#' \code{instance_document} returns a list containing values from the \href{http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/instance-identity-documents.html}{Instance Identity Document}, including the instance ID, AMI ID, region, availability zone, etc.
+#' 
 #' \code{metadata} is a list of functions to return various metadata values for the currently running EC2 instance. These are only meant to be called from an EC2 instance; no guarantees are made about behavior on other platforms. Two functions: \code{versions()} and \code{meta_data_items()} return the versions of the metadata, and the set of top-level metadata items, respectively.
 #' 
 #' The function \code{item()} retrieves a particular metadata item specified by its full path.
 #'
-#' The remaining functions in the list are aliases for potentially commonly needed metadata items
-#' @details Generally, this will return a character string containing the requested information, otherwise a \code{NULL} if the response is empty. The \code{iam_role()} function returns a list. An error will occur if, for some reason, the request otherwise fails.
+#' The remaining functions in the list are aliases for potentially commonly needed metadata items.
+#' 
+#' @return \code{is_ec2} returns a logical. Generally, all other functions will return a character string containing the requested information, otherwise a \code{NULL} if the response is empty. The \code{iam_role()} function returns a list. An error will occur if, for some reason, the request otherwise fails.
 #' @examples
 #' names(metadata)
 #' 
 #' \dontrun{
+#' if (is_ec2()) {
 #'   metadata$versions()
 #'   metadata$items()
 #' 
@@ -74,6 +85,10 @@ is_ec2 <- function() {
 #' 
 #'   # get an arbitrary metadata item
 #'   metadata$item("meta-data/placement/availability-zone")
+#'   
+#'   # get region from instance identity document
+#'   instance_document()$region
+#' }
 #' }
 #' @references \href{http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-instance-metadata.html}{Metadata Documentation}
 #' @importFrom jsonlite fromJSON
@@ -129,7 +144,7 @@ metadata <- list(
         get_instance_metadata(item = "meta-data/local-ipv4", ...)
     },
     availability_zone = function(...) {
-        get_instance_metadata(item = "placement/availability-zone", ...)
+        get_instance_metadata(item = "meta-data/placement/availability-zone", ...)
     },
     public_hostname = function(...) {
         get_instance_metadata(item = "meta-data/public-hostname", ...)

R/onLoad.R

@@ -0,0 +1,9 @@
+.onAttach <- function(libname, pkgname) {
+    if (is_ec2() && Sys.getenv("AWS_DEFAULT_REGION") == "") {
+        reg <- try(instance_document()$region, silent = TRUE)
+        if (!inherits(reg, "try-error")) {
+            Sys.setenv("AWS_DEFAULT_REGION" = reg)
+            packageStartupMessage(sprintf("Setting environment variable AWS_DEFAULT_REGION to '%s'", reg))
+        }
+    }
+}