Signed-off-by: Daniel Nephin <dnephin@docker.com>

Signed-off-by: Liping Xue <lipingxue@gmail.com>
Change to enable volume name can be customized.
Signed-off-by: Liping Xue <lipingxue@gmail.com>

Change to enable volume name can be customized.

Remove unused debug info.

Address comments from Daniel and solve the lint error.
Signed-off-by: Liping Xue <lipingxue@gmail.com>

Address Daniel's comments to print warning message when name of external volume is set in loader code.
Signed-off-by: Liping Xue <lipingxue@gmail.com>

Address Daniel's comments to return error when external volume is set in loader code.
Signed-off-by: Liping Xue <lipingxue@gmail.com>

Address Daniel's comments to return error when external volume is set in loader code.
Signed-off-by: Liping Xue <lipingxue@gmail.com>

Remove the case that specifying external volume name in full-example.yml.

More fix.

Add unit test.
Signed-off-by: Liping Xue <lipingxue@gmail.com>

Address comments from Daniel, move the schema change to v3.4.
Signed-off-by: Liping Xue <lipingxue@gmail.com>

Address comments from Sebastiaan. Signed-off-by: Liping Xue <lipingxue@gmail.com>

Address comments from Misty.
Signed-off-by: Liping Xue <lipingxue@gmail.com>