|
@@ -94,8 +94,8 @@ instructions.
|
|
|
Whenever possible, Docker will re-use the intermediate images (cache),
|
|
|
to accelerate the `docker build` process significantly. This is indicated by
|
|
|
the `Using cache` message in the console output.
|
|
|
-(For more information, see the [Build cache section](https://docs.docker.com/engine/userguide/eng-image/dockerfile_best-practices/#/build-cache)) in the
|
|
|
-`Dockerfile` best practices guide:
|
|
|
+(For more information, see the [Build cache section](https://docs.docker.com/engine/userguide/eng-image/dockerfile_best-practices/#build-cache) in the
|
|
|
+`Dockerfile` best practices guide):
|
|
|
|
|
|
$ docker build -t svendowideit/ambassador .
|
|
|
Sending build context to Docker daemon 15.36 kB
|
|
@@ -1281,18 +1281,28 @@ This Dockerfile results in an image that causes `docker run`, to
|
|
|
create a new mount point at `/myvol` and copy the `greeting` file
|
|
|
into the newly created volume.
|
|
|
|
|
|
-> **Note**:
|
|
|
-> When using Windows-based containers, the destination of a volume inside the
|
|
|
-> container must be one of: a non-existing or empty directory; or a drive other
|
|
|
-> than C:.
|
|
|
+### Notes about specifying volumes
|
|
|
|
|
|
-> **Note**:
|
|
|
-> If any build steps change the data within the volume after it has been
|
|
|
-> declared, those changes will be discarded.
|
|
|
+Keep the following things in mind about volumes in the `Dockerfile`.
|
|
|
|
|
|
-> **Note**:
|
|
|
-> The list is parsed as a JSON array, which means that
|
|
|
-> you must use double-quotes (") around words not single-quotes (').
|
|
|
+- **Volumes on Windows-based containers**: When using Windows-based containers,
|
|
|
+ the destination of a volume inside the container must be one of:
|
|
|
+
|
|
|
+ - a non-existing or empty directory
|
|
|
+ - a drive other than `C:`
|
|
|
+
|
|
|
+- **Changing the volume from within the Dockerfile**: If any build steps change the
|
|
|
+ data within the volume after it has been declared, those changes will be discarded.
|
|
|
+
|
|
|
+- **JSON formatting**: The list is parsed as a JSON array.
|
|
|
+ You must enclose words with double quotes (`"`)rather than single quotes (`'`).
|
|
|
+
|
|
|
+- **The host directory is declared at container run-time**: The host directory
|
|
|
+ (the mountpoint) is, by its nature, host-dependent. This is to preserve image
|
|
|
+ portability. since a given host directory can't be guaranteed to be available
|
|
|
+ on all hosts.For this reason, you can't mount a host directory from
|
|
|
+ within the Dockerfile. The `VOLUME` instruction does not support specifying a `host-dir`
|
|
|
+ parameter. You must specify the mountpoint when you create or run the container.
|
|
|
|
|
|
## USER
|
|
|
|