fetchs3: init simple S3 downloader

1 files changed, 29 insertions, 0 deletions

diff --git a/pkgs/build-support/fetchs3/default.nix b/pkgs/build-support/fetchs3/default.nix
new file mode 100644
index 000000000000..a5cdbd150b8b
--- /dev/null
+++ b/pkgs/build-support/fetchs3/default.nix
@@ -0,0 +1,29 @@
+{ stdenv, runCommand, awscli }:
+
+{ s3url
+, sha256
+, region ? "us-east-1"
+, credentials ? null # Default to looking at local EC2 metadata service
+, executable ? false
+, recursiveHash ? false
+, postFetch ? null
+}:
+
+let
+  credentialAttrs = stdenv.lib.optionalAttrs (credentials != null) {
+    AWS_ACCESS_KEY_ID = credentials.access_key_id;
+    AWS_SECRET_ACCESS_KEY = credentials.secret_access_key;
+    AWS_SESSION_TOKEN = credentials.session_token ? null;
+  };
+in runCommand "foo" ({
+  buildInputs = [ awscli ];
+  outputHashAlgo = "sha256";
+  outputHash = sha256;
+  outputHashMode = if recursiveHash then "recursive" else "flat";
+} // credentialAttrs) (if postFetch != null then ''
+  downloadedFile="$(mktemp)"
+  aws s3 cp ${s3url} $downloadedFile
+  ${postFetch}
+'' else  ''
+  aws s3 cp ${s3url} $out
+'')