Deploy via ssh

[jezek]

This PR adds the ability to deploy via ssh.

I've splitted the PR into thematic commits for easier review.

• The first 6 commits (28a4ea0, ..., 7e1fd88) are refactoring changes, which moves all the adb commands in crossbuilder script into functions with a concrete goal (exec_device, push_device, ...), one adb type per commit.
• The 7th commit (9eddcb7) refactors the options parameter evaluation before the first adb command call (missing packages checks), to be able to not use adb if --ssh option is passed.
• The 8th commit (f27805e) is the actual ssh code logic.
• The last 2 commits (6c1dd34, 4ea693c) are documentation updates and a fix to be able to use --ssh with --no-deb option.

Note: This solves #42 and #14 and renders some changes as unnecessary in PR #53.

[mardy]

Thanks, this looks excellent! Just please give me a couple of days to try it :-)

We might want to redo a bit the logic, I'd like to have a function device that takes the action as first parameter (and all other action-specific parameters after that), which takes care of invoking the right backend. Something like this:

# Somewhere near the beginning, after parsing the command-line parameters:
if [ ! -z "$SSH_ADDRESS" ] ; then
    DEVICE_BACKEND=ssh
else
    DEVICE_BACKEND=adb
fi

device () {
    ACTION="$1"
    shift
    ${DEVICE_BACKEND}_${ACTION} "$@"
}

which will be used like this:

device push $DEBS_TARBALL /tmp/repo/

so we will need to have for each action a couple of functions like:

ssh_push () {
    local last="${!#}"
    local argv=( "${@:1:$#-1}" )
    scp ${argv[@]} "$SSH_ADDRESS:$last"
}

adb_push () {
    adb push "$@"
}

What do you think? In any case, it's something that we can do after merging this.

[mardy]

I didn't try the new SSH backend, but the adb one works like a charm, so let's merge this. Thanks again!