As someone who maintains a shell-script project across several "sh-like" shells, I can say the edge cases cause enough work and testing hassles that you shouldn't undertake it lightly. Is there any particular need to run these tools under a non-bash shell?
Doug On Mon, Apr 14, 2014 at 12:26 PM, Ben Nemec <[email protected]> wrote: > tldr: I propose we use bash explicitly for all diskimage-builder scripts (at > least for the short-term - see details below). > > This is something that was raised on my linting changes to enable set -o > pipefail. That is a bash-ism, so it could break in the diskimage-builder > scripts that are run using /bin/sh. Two possible fixes for that: switch to > /bin/bash, or don't use -o pipefail > > But I think this raises a bigger question - does diskimage-builder require > bash? If so, I think we should just add a rule to enforce that /bin/bash is > the shell used for everything. I know we have a bunch of bash-isms in the > code already, so at least in the short-term I think this is probably the way > to go, so we can get the benefits of things like -o pipefail and lose the > ambiguity we have right now. For reference, a quick grep of the > diskimage-builder source shows we have 150 scripts using bash explicitly and > only 24 that are plain sh, so making the code truly shell-agnostic is likely > to be a significant amount of work. > > In the long run it might be nice to have cross-shell compatibility, but if > we're going to do that I think we need a couple of things: 1) Someone to do > the work (I don't have a particular need to run dib in not-bash, so I'm not > signing up for that :-) 2) Testing in other shells - obviously just changing > /bin/bash to /bin/sh doesn't mean we actually support anything but bash. We > really need to be gating on other shells if we're going to make a > significant effort to support them. It's not good to ask reviewers to try > to catch every bash-ism proposed in a change. This also relates to some of > the unit testing work that is going on right now too - if we had better unit > test coverage of the scripts we would be able to do this more easily. > > Thoughts? > > Thanks. > > -Ben > > _______________________________________________ > OpenStack-dev mailing list > [email protected] > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev _______________________________________________ OpenStack-dev mailing list [email protected] http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
