Ludovic Courtès (2015-06-03 12:52 +0300) wrote: > Alex Kost <[email protected]> skribis: > >> I see some inconsistency in specifying text / text files in an >> operating-system declaration: > > Yeah, I agree it is somewhat annoying that there’s no single way to > handle this. But... > >> - ‘sudoers’ and ‘issue’ want plain strings; >> >> - ‘hosts-file’ and ‘mingetty-service’ (#:motd argument) want a >> 'text-file' monadic procedure; >> >> - some other services (‘syslog-service’, ‘lirc-service’, ...) want file >> names (of the configuration files). > > In reality they take a “file”, not a file name. A file is an object > that within a gexp expands to a file name. So it can be a ‘local-file’ > object, a derivation, etc.
Ah, thanks! I didn't realize that ‘local-file’ or a derivation may be used there. >> As for me, I prefer the latter variant. But I think the best would >> be to add support for any of the above possibilities for all services >> or operating-system fields. > > An important criterion is whether the file needs to contain references > to store items or not. For ‘sudoers’ and ‘issue’, that’s normally not > the case, and these are usually small files or computable files, so I > think it’s fine to use strings here (more convenient than files.) Well, I don't agree about ‘sudoers’. It may be a really big file. Mine is not so big, but it is 40 lines long (including some useful comments), so I have to use some additional guile code to convert the contents of the file into string. > Using monadic values as for ‘hosts-file’ and #:motd is not nice. These > should be changed to use either a string or a file. > > The best would be to always use a file-like object. I’ve just added > ‘plain-file’ for that reason. Now I would change #:motd and > ‘hosts-file’ to take a file-like object rather than a monadic value. > > WDYT? I beg a pardon, but if I inderstand it correctly (probably not), I don't see a difference from the user point of view. Previously it was: (hosts-file (text-file "hosts" "...")) and now it would be: (hosts-file (plain-file "hosts" "...")) > This brings up the question of how far we should go on the declarative > side: Similar to ‘local-file’ and ‘plain-file’, should we add more > declarative types, say for ‘gexp->derivation’? > > My current inclination would be to not add anything beyond ‘local-file’ > and ‘plain-file’: These two are useful in OS configurations, so that’s > fine, but for more elaborate things people should just use the > procedural interface. Thoughts? I think I'm not competent as I have a vague understanding of all this stuff and of user's needs (except mine ☺). What I would like to have, is a possibility to specify my configuration files for various services and operating-system fields. I don't want to write text configs in my os-config.scm file (as it happens now with ‘hosts-file’). I'm very happy with the current behaviour of ‘syslog-service’, ‘lirc-service’ and ‘console-keymap-service’ where I just specify file names, e.g.: (syslog-service #:config-file "/home/me/my-favourite-syslog.conf") and I like this ↑ way of specifying configurations very much! That's what I would like to see in ‘sudoers’ and ‘hosts-file’ fields. -- Thanks, Alex
