I can see in the documentation for libertine-container-manager (that's libertine-container-manager -- help) That the exec option should be able to execute an arbitrary command.
I can't however get it to do anything other than spew python warnings at me ( Can't convert NoneType to str ). I have tried the following:
libertine-container-manager exec setxkb dk dvorak
libertine-container-manager exec "setxkb dk dvorak"
libertine-container-manager exec="setxkb dk dvorak"
echo "setxkb dk dvorak" | libertine-container-manager exec
None of these gave the desired result (or anything not resulting in an error really)
I'm on Ubuntu touch on an M10 that is not remounted rw.