4 > dgit - treat the archive as a git remote
6 > COLOUR 1 using dgit on other contributors' packages
8 > COLOUR 2 dgit for the Debian package maintainer
13 Hi. I'm here to plug dgit, which is a system for treating the Debian
14 archive like a git remote.
16 I'm going to talk for about 35 minutess and then I'll take questions.
19 When we work on Debian we take on different roles. The biggest
20 difference is between the maintainer (or maintainers) of a package,
21 working on their own package, and everyone else.
23 I'm going to start by presenting dgit from the point of view of
24 everyone else: NMUers, sponsorship, teams doing cross-archive work
25 like transitions and reproducible builds, bug squashers, downstreams,
26 users, and so on. Maintainers, please be patient - I'll get to you.
31 The point of dgit is that it lets everyone treat the archive as if it
32 were a git repository.
34 You can dgit clone any package, in any suite in the archive (so, for
35 example, sid or experimental) and you will get a git tree which is
36 exactly the same as dpkg-source -x.
38 You can then work on the package in git, the way you would work in git
39 with any other project. In particular, you can:
42 * cherry pick changes from other branches
43 * git reset, git clean
44 * git rebase -i to polish a more complex set of changes into
47 If you want so share your work-in-progress with others, you can git
48 push your branch anywhere suitable, so they can fetch it.
50 If you have the right authority you can also dgit push, to upload
51 (after doing a build).
55 > include git-dpm, git, etc.
57 dgit is not a replacement for existing git packaging tools; it's
58 intended to complement them. So (unlike git-dpm) dgit does not define
59 a git history structure, and (unlike git-buildpackage) it does not
60 define a branch structure. Nor does it require a particular source
64 The dgit history structure is up to the maintainer. If you are doing
65 a straightforward NMU you should produce a well-structured linear
66 sequence of commits, as you would for any git upstream. If the source
67 package is `3.0 (quilt)', you should not touch debian/patches; dgit
68 will take care of that for you.
70 Unless the maintainer uses dgit, the history you see in dgit will not
71 be the maintainer's history. This is because maintainers' git
72 branches often differ from the source packages in the archive.
74 So dgit may have to synthesise a git history. The history you see in
75 dgit will then have a very basic branch and commit structure, rather
76 than representing the package's actual history.
79 ==== history comparison slide
83 Which brings me onto the other side of this talk: dgit for
86 For the reasons I've explained, downstream dgit users would like you
87 to use dgit for your maintainer uploads. They will then be able to
88 see, and directly work with, your own history.
90 But it's in your own interests, too:
92 If you use dgit, you will be able to directly merge and/or cherry-pick
93 NMUs, patches proposed via pull-request emails, and so on: Because, in
94 this case, the dgit-using contributor will have based their work on
97 Using dgit for your maintainer uploads will put your own history on
98 browse.dgit.debian.org, rather than showing dgit's stub history (which
99 can also be out of date).
101 If you use dgit push, you get an extra check that the source package
102 you are uploading is exactly the same as your git HEAD. This can
103 save you some dsc-based checks.
105 And, as I say, non-maintainer dgit users will thank you.
109 > with push requirement clearer
111 dgit push imposes only two requirements on your git trees. These stem
112 directly from dgit's design goals.
114 The most important requirement is that your git tree is identical to
115 the unpacked source package. (Technically, in the case of a `3.0
116 (quilt)' package, it is what is sometimes called a `patches applied
117 packaging branch without .pc'.)
119 For all native packages, and for users of git-dpm and raw git, this is
120 already the interchange format. These maintainers can start using
121 dgit right away. Please do!
123 For those using git-buildpackage with `3.0 (quilt)', things are a bit
124 more complicated. I'm told that gbp pq can be used to generate a
125 patches-applied branch, and that some users prefer to use that as the
126 interchange git branch. I'm talking to the git-buildpackage
127 maintainers about gbp integration.
130 The other requirement of dgit is simply that the dgit branches are
131 fast-forwarding. So if your tools have made a rebasing branch, you
132 may need to do something like
133 git merge -s ours dgit/sid
134 before pushing. I'm intending to provide some rather more cooked
135 way to do this but I have decided the exact shape yet.
138 ==== structure diagram
141 There are a few other things I ought to cover, since they often come
142 up. They're are relevant to maintainers and others:
145 DMs currently need to email a signed copy of their ssh key, in order
149 The dgit view does not generally include the package upload history.
150 git-import-dscs can produce a git branch representing the upload
151 history, but dgit does do that itself.
153 One could push such a branch to the archive with dgit push. But, it
154 seems to me that the git history structure ought to up to the
155 maintainer, and if the maintainer chooses to use dgit, the
156 maintainers's existing git history is probably better.
159 It is normally best to use one of dgit's build operations to build for
160 upload. This is mainly because most other tools remove .gitignore by
161 default. dgit requires that the source package and git tree are the
162 same, so if your git tree has .gitignore in it, your source package
166 Many packages have strangely-behaved or plain buggy clean targets.
167 Because dgit knows that your git tree is canonical, it can help work
168 around this: you can tell dgit to use git clean instead, avoiding the
169 package's clean target entirely.
172 Some maintainers' source packages contain files not in their git
173 branches: most commonly, autotools output. This is not compatible
174 with dgit's purpose, namely to provide a git view of what's actually
177 But nowadays most people recommend that the package build should
178 always rerun autotools, anyway. If you do that, then neither your git
179 tree nor your source package need contain the autotools output and all
182 Alternatively, you can commit the autotools output to git.
185 ==== Future plans slide
188 > automatic sending of the NMU diff email
190 > source-only one step push
192 > use of the dgit git repo server (other branches and tags) for general
195 > more assistance for use with raw git
197 > automatic tracking of uploads into the dgit suite branches
202 > better workflow documentation for integration with existing git tools
204 > better gbp integration
209 I have a number of plans for the future, some of which I need help
210 with. I don't have time I'm afraid to go through them now.
212 Instead, I'm going to open the talk up to questions now.