This function was exported in e43c792
for use of "docker app", which is now deprecated. The signature of this
function also depended on a non-exported type so it could not be used
externally.

Make it internal again, as it was never designed to be exported. There
are no known external consumers of this function.

Signed-off-by: Sebastiaan van Stijn <[email protected]>

This function was exported in e43c792
for use of "docker app", which is now deprecated. The signature of this
function also depended on a non-exported type, so it could not be used
externally.

Make it internal again, as it was never designed to be exported. There
are no known external consumers of this function.

Signed-off-by: Sebastiaan van Stijn <[email protected]>

This function was exported in 812f113
for use in other parts of the CLI, but it's now only used locally.

Make it internal again, as it was never designed to be exported. There
are no known external consumers of this function, but deprecating it
first, in case there are.

Signed-off-by: Sebastiaan van Stijn <[email protected]>

Same functionality, but implemented with atomicwriter. There's a slight
difference in error-messages produced (but can be adjusted if we want).

Before:

    docker image save -o ./no/such/foo busybox:latest
    failed to save image: invalid output path: directory "no/such" does not exist

    docker image save -o /no/permissions busybox:latest
    failed to save image: stat /no/permissions: permission denied

After:

    docker image save -o ./no/such/foo busybox:latest
    failed to save image: invalid file path: stat no/such: no such file or directory

    docker image save -o /no/permissions busybox:latest
    failed to save image: failed to stat output path: lstat /no/permissions: permission denied

Signed-off-by: Sebastiaan van Stijn <[email protected]>

Same functionality, but implemented with atomicwriter. There's a slight
difference in error-messages produced (but can be adjusted if we want).

Before:

    docker container export -o ./no/such/foo mycontainer
    failed to export container: invalid output path: directory "no/such" does not exist

    docker container export -o /no/permissions mycontainer
    failed to export container: stat /no/permissions: permission denied

After:

    docker container export -o ./no/such/foo mycontainer
    failed to export container: invalid file path: stat no/such: no such file or directory

    docker container export -o /no/permissions mycontainer
    failed to export container: failed to stat output path: lstat /no/permissions: permission denied

Signed-off-by: Sebastiaan van Stijn <[email protected]>

Signed-off-by: Sebastiaan van Stijn <[email protected]>