talk about the new exec form of RUN (Closes implemented by
Docker-DCO-1.1-Signed-off-by: Sven Dowideit (github: SvenDowideit)
@@ -147,17 +147,23 @@ the generated images.
3.3 RUN
-------
- ``RUN <command>``
+RUN has 2 forms:
-The ``RUN`` instruction will execute any commands on the current image
-and commit the results. The resulting committed image will be used for
-the next step in the Dockerfile.
+* ``RUN <command>`` (the command is run in a shell - ``/bin/sh -c``)
+* ``RUN ["executable", "param1", "param2"]`` (*exec* form)
+
+The ``RUN`` instruction will execute any commands in a new layer on top
+of the current image and commit the results. The resulting committed image
+will be used for the next step in the Dockerfile.
Layering ``RUN`` instructions and generating commits conforms to the
core concepts of Docker where commits are cheap and containers can be
created from any point in an image's history, much like source
control.
+The *exec* form makes it possible to avoid shell string munging, and to ``RUN``
+commands using a base image that does not contain ``/bin/sh``.
+
Known Issues (RUN)
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