This PR proposes a way for Pebble to load layers from multiple sources first, before then loading from the $PEBBLE directory. This is required when pebble is run as a non-root user in a container with pebble layers already defined at the default $PEBBLE location of /var/lib/pebble/default.
By setting $PEBBLE to a directory writeable by a non-root user, while also setting $PEBBLE_IMPORT to /var/lib/pebble/default, the pebble daemon is able to load layers previously defined in the default directory by a container image author.
$PEBBLE_IMPORT can be a colon (:) delimited ordered list of paths to directories in the format of the pebble data directory ($PEBBLE). Each directory will have a layers/ sub-directory.
It is expected that the following pebble invocation,
PEBBLE=/var/lib/pebble/charm PEBBLE_IMPORT=/var/lib/pebble/default:/var/lib/pebble/intermediate pebble run; would load layers like so:
This PR proposes a way for Pebble to load layers from multiple sources first, before then loading from the
$PEBBLEdirectory. This is required when pebble is run as a non-root user in a container with pebble layers already defined at the default$PEBBLElocation of/var/lib/pebble/default.By setting
$PEBBLEto a directory writeable by a non-root user, while also setting$PEBBLE_IMPORTto/var/lib/pebble/default, the pebble daemon is able to load layers previously defined in the default directory by a container image author.$PEBBLE_IMPORTcan be a colon (:) delimited ordered list of paths to directories in the format of the pebble data directory ($PEBBLE). Each directory will have alayers/sub-directory.It is expected that the following pebble invocation,
PEBBLE=/var/lib/pebble/charm PEBBLE_IMPORT=/var/lib/pebble/default:/var/lib/pebble/intermediate pebble run;would load layers like so:NOTE: order numbers can be re-used globally, but labels must be unique globally.
For tooling to determine where configuration originated from, see https://github.com/canonical/pebble/pull/342
JU090