Support AWS Lambda custom runtime (#305)

* environment variable to disable handling of SIGPIPE

* rename env variable to BABASHKA_DISABLE_PIPE_HANDLER

README.md

@@ -1104,6 +1104,10 @@ $ docker run --rm script 1 2 3
 Your command line args: (1 2 3)
 ```
 
+## Package babashka script as a AWS Lambda
+
+AWS Lambda runtime doesn't support signals, therefore babashka has to disable handling of the SIGPIPE. This can be done by setting `BABASHKA_DISABLE_PIPE_HANDLER` to `true`.
+
 ## Thanks
 
 - [adgoji](https://www.adgoji.com/) for financial support

src/babashka/main.clj

@@ -289,7 +289,8 @@ Everything after that is bound to *command-line-args*."))
 
 (defn main
   [& args]
-  (handle-pipe!)
+  (when-not (Boolean/valueOf ^String (System/getenv "BABASHKA_DISABLE_PIPE_HANDLER"))
+    (handle-pipe!))
   #_(binding [*out* *err*]
       (prn "M" (meta (get bindings 'future))))
   (binding [*unrestricted* true]