Mercurial - Clone another repo upon clone - mercurial

I am currently taking a class where the teacher is collecting our homework by cloning our individual homework repos; we have a new repo per homework assignment. I've been writing a bunch of helper functions and in order to use those functions I've just been copying and pasting into each new homework assignment.
What I want to do is create another repo that holds all of my utility functions so I can maintain a single, up-to-date, codebase. Is there any way that when my teacher clones my homework assignment repo, I can have it also clone my includes repo and include that in the same directory?
I'm looking for a functionality similar to running pip install git+ssh://mygitrepo.git where you can have the setup.py auto install the dependencies.

This sounds like a good application of subrepos.
Your helper files could live in a stand-alone repository. Then each assignment could include a link to it. When the teacher clones the assignment and then updates to a specific revision, it automatically clones the subrepo.

Related

Configuring Hudson/Jenkins to build all mercurial branches

How do I configure Hudson/Jenkins (we're still using Hudson) to build all branches with the mercurial plugin? I have seen that we can create separate jobs/etc for specific branches, but we branch often enough that it would be good to just build all branches.
The only way I can think of (and I haven't tried it) is to have our build script [executed by Hudson on the slave] somehow figure out which branch is the latest commit and then hg update -r itself, rather than the mercurial plugin doing it.
I would love to find out a more elegant/correct way to do this!
I've also been looking for this support in the Jenkins Mercurial plugin (partly because it's supported by its Git plugin) but the following Jenkins tickets seem to indicate that this is yet not implemented:
https://issues.jenkins-ci.org/browse/JENKINS-11102
https://issues.jenkins-ci.org/browse/JENKINS-10558
One option if you have branches that are used regularly (ie, named branches for milestones or developers) is to create copies of your master build and simply point it to that branch.
For example on my team's build server we have production ('default' branch) and development ('dev' branch). Our builds are run by feeding the branch name as a parameter to the build script (so it's a simple, one-field change from a copy of the main job).
Obviously this won't scale beyond a handful of branches, but it might be enough for your needs.

"factorizing" a mercurial repository on kiln

Summarized questions:
What is the simplest (and best) way to shift a group of files from an existing repository to a new sub repository, so those files can be integrated with other parent repositories, some of which may not yet exist?
Do files in subrepositories need to be in discrete folders, or can they exist alongside other files?
Detailed Questions:
I have begun the process of creating multiple repositories representing several projects that have shared components, and that is going well, thanks to SO and some helpful answers to my question here
As I move on to adding a second project I notice there are a few files in my projects that are duplicated, and are essentially the same thing, with enough similarity to warrant taking them out of a main project repository and creating a new subrepository so they can be
used by any new projects I begin, and
removed from other existing repositories, since they are identical.
I am assuming the best way is to simply create a new repository, move the files across on the local file system, push both repositories, and then create a .hgsub file and proceeed as in the answer to my earlier question. This would obviously then shift the files concerned to a subfolder in the local file system under each main project, which i can live with, but it does raise the hypothetical question - is it possible to have a list of files in a repository that are effectively part of a sub repository but reside alongside other files (i.e. not in a sub folder).
If I wanted to (for example) have a "acme.h" file in each project that is part of another repository could I do this? as it happens, I don't need to do this at this point in time, and in my current situation it would be better from a design point of view to have the files I need to "refactor" into another repository in their own subfolder, however that might not always be the case. I use refactor in quotes here, as strictly speaking it's more about refactoring duplicated files that is refactoring code - however the same principle applies.
hopefully my questions are succinct enough to be answered without too much more explanation.
Thanks for summary, makes it much easier to answer!
What is the simplest (and best) way to shift a group of files from an existing repository to a new sub repository, so those files can be integrated with other parent repositories, some of which may not yet exist?
You can use the convert extension to extract a directory from an existing Mercurial repository. You'll want to use the --filemap flag and in the filemap you include the directory you want and rename it to the root. See hg help convert for more info.
After you get a smaller repository with the
Do files in subrepositories need to be in discrete folders, or can they exist alongside other files?
They must be in their own folders. This is simply because that's how a repository looks like in Mercurial, Git, Subversion, ... When you're dealing with subrepositories, then Mercurial is not tracking the files inside the subrepo: it's just asking some (other) system to make a checkout of repository foo at some location.
So when your .hgsub file has
foo = foo
bar = [git]bar
baz = [svn]baz
then Mercurial will notice this on hg update and run
hg clone default-path-of-this-repo/foo foo
git clone default-path-of-this-repo/bar bar
svn checkout default-path-of-this-repo/baz baz
for your. This explains why subrepostories are directories in the outer repository: that's simply what a clone/checkout looks like these days.
As you can see, subrepositories can be of different types. It's conceivable that someone could add a RCS subrepository type for tracking individual files. They would then not have to live in a directory.

Mercurial and code reviews; good workflow?

I'm in a small distributed team using Mercurial for a central repository. We each clone it via ssh onto our own linux boxes. Our intent is to review each others' work before pushing changes up to the central repository, to help keep central's tip clean. What is a good way to share code between developers on different linux boxes? I'm new to Mercurial. The options I can think of (through reading, not experience) are:
1: Author commits all local changes and updates working clone with central's tip. Author uses hg bundle, if there's a way to specify which local revs to include in the bundle. (an experiment showed me "bundle" only grabs uncommited changes, even if there are previous local commits that central doesn't know about) Author gets bundle file to reviewer. Reviewer creates a new clean clone from central's tip, and imports the bundle into that clone.
or,
2: After both author and reviewer fetch from central's tip, author uses patch and reviewer imports the patch.
or,
3: Author pushes to reviewer or reviewer pulls from author (but how, exactly? What I read is only about pushing and pulling to/from the original served repository, and/or on the same box instead of between different linux boxes.)
4: Forget reviewing the code prior to pushing to central; go ahead and push, using tags to identify what's been reviewed or not, and use Hudson (already working) to tag the latest safe build so team members can know which one to pull from.
If your team uses Mercurial and does code reviews, how do you do get the reviewer to see your changes?
Most of these are possible, some are more tedious than others.
You can use bundle by specifying the tip of the central repo as the --base:
hg bundle --base 4a3b2c1d review.bundle
Might as well just use bundle. That way, the changeset data is also included.
You can push (and pull) to (from) any repository that has a common ancestor(s). If you want to pull from one of your colleagues, they just need to run hg serve on their machine, and you will be able to pull.
This also works, but you will have to maintain multiple heads and be careful about merging. If you don't, it can become easy to base a stable change on top of an unreviewed changeset, which will make it hard to undo if you need to fix that unreviewed changeset later.
Of the options you presented, #1 and #3 are probably easiest, just depending on whether or not you can reach each other's boxes.
On a related note: This is the question that got my colleague and I started on developing Kiln, our (Fog Creek's) Mercurial hosting and code review tool. Our plan, and the initial prototype, would keep multiple repositories around, one "central" repository, and a bunch of "review" repositories. The review process would be started by cloning the central repo into a review repo on the server, and then running a full repo diff between the two, with a simple web interface for getting and viewing the diffs.
We've evolved that workflow quite a bit, but the general idea, having a branch repo to push unreviewed changes to and an interface to review them before you push them into the central repo, is still the same. I don't want to advertise here, but I do recommend giving it a try.
Half answer to this question is using ReviewBoard with Mercurial extention. It allows to push certain revisions for review by issuing the following command
hg postreview tip
I'll add a 5th option - do all development work on named branches, preferably one per task. Allow anything to be committed to a "development" named branch, whether it's in working state or not.
Push to the central repository, have reviewer pull the branch. Perform the review on the branch.
When the review has passed, merge the development work into the appropriate feature branch.
This workflow, which is (to me) surprisingly unpopular, has many advantages:
All work gets committed - you do not have to wait for a review to be done before committing.
You will not build off the wrong version. You only ever build from the feature branch.
In-progress work does not interfere with other developers.
From the development branch, you can either look at the latest changes (e.g. the changesets addressing review comments), compare with the branch point, or compare with the latest feature branch - all of which can give useful information.

Moving from Subversion to Mercurial - how to adapt the workflow and staging/integration systems?

We got all psyched about from from svn to hg and as the development workflow is more or less flushed out, here remains the most difficult part - staging and integration system.
Hopefully this question goes a bit further then your common 'how do I move from xxx to Mercurial'. Please forgive long and probably poorly written question :)
We are web shop that does a lot of projects(mainly PHP and Zend), so we have one huge svn repo, with like 100+ folders, each representing a project with it's own tags,branches and trunk of course. On our integration and testing server(where QA and clients look at work results and test stuff) everything is pretty much automated - Apache is set to pick up new projects automatically creating vhost for each project/trunk; mysql migration scripts right there in trunk too and developers can apply them through simple web-interface. Long story short our workflow is this now:
Checkout code, do work, commit
Run update on the server via web interface(this basically does svn up on server on a particular project and also run db-migration script if needed)
QA changes on the server
This approach is certainly suboptimal for large projects when we have 2+ developers working on the same code. Branching in svn was only causing more headaches, well, hence moving to Mercurial. And here is where the question lies - how does one organize efficient staging/integration/testing server for this type of work(where you have many projects, say single developer could be working on 3 different projects in 1 day).
We decided to have 'default' branch tracking production essentially and then make all changes in individual branches. In this case though how can we automate staging updates for each branch? If earlier for one project we almost always were working on trunk, so we needed one DB, one vhost, etc. now we potentially talking about N-databases per project, N-vhost configs and etc. Then what about CI stuff(such as running phpDocumentor and/or unit tests)? Should it only be done on the 'default'? On branches?
I wonder how other teams solve this issue, perhaps some best practices that we're not using or overlooking?
Additional notes:
Probably worth mentioning that we've picked Kiln as a repo hosting service(mostly since we're using FogBugz anyway)
This is by no means the complete answer you'll eventually pick, but here are some tools that will likely factor into it:
repositories without working directories -- if you clone -U or hg update null you get a repository with no working directory (only the .hg). They're better on the server because they take up less room and no one is tempted to edit there
changegroup hooks
For that last one the changegroup hook runs whenever one or more changesets arrive via push or pull and you can have it do some interesting things such as:
push the changesets on to another repo depending on what has arrived
update the receiving repo's working directory
For example one could automate something like this using only the tools described above:
developer pushes five changesets to central-repo/project1/main
last changeset is on branch 'my-experiment' so csets are automatually re-pushed to optionally created repo central-repo/project1/my-experiment
central-repo/project1/my-experiment automatically does hg update tip which is certain to be on the my-expiriment branch
central-repo/project1/my-experiment automatically runs tests in its working dir and if they pass does a 'make dist' that deploys, which might set up database and vhost too
The biggie, and chapter 10 in the mercurial book covers this, is to not have the user waiting on that process. You want the user to push to a repo that contains possibly-okay-code and the automated processed do the CI and deploy work, which if it passes ends up being a likely-okay repo.
In the largest mercurial setup in which I've worked (20 or so developers) we got to the point where our CI system (Hudson) was pulling from the maybe-ok repos for each periodically then building and testing, and handling each branch separately.
Bottom line: all the tools you need to setup whatever you'd like probably already exist, but gluing them together will be one-off sort of work.
What you need to remember is that DVCS (vs. CVCS) introduces another dimension to versioning:
You don't have to rely anymore only on branching (and get a staging workspace from the right branch)
You now have with DVCS the publication workflow (push/pull between repo)
Meaning your staging environment is now a repo (with the full history of the project), checked out at a certain branch:
Many developers can push many different branches to that staging repo: the reconciliation process can be done in isolation within that repo, in a "main" branch of your choice.
Or they can pull that staging branch in their repo and test things out before pushing back.
From Joel's tutorial on Mercurial HgInit
A developer don't necessary have to commit for other to see: the publication process in a DVCS allows for him/her to pull the staging branch first, reconcile any conflict locally, and then push to the staging repo.

Fetching a single file from another mercurial repository [duplicate]

This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
Mercurial: copying ONE file and its history to another repository
I have several repositories in my local machine.
One is my main code, another is an assortment of useful code/tools.
These are two fundamentally different repos. It might make sense to setup a new repo and pull these two in as sub-repos, but I want to wait until Mercurial devs mark sub-repos as non-experimental before I do that.
One of the useful code files has become so useful, I want to put it into my main code area...but I want to maintain its history. This will, of course, result in some variant of a fork, but that's acceptable. (best case would be being able to push-pull it back and forth and keep updating its history).
I'd just use the subrepo feature that came online in 1.3. It might change slightly, but you won't be left high and dry backwards compatibility wise.
If you can't bring yourself to so, then what you need to do is:
use hg convert with a filemap that deletes all files except the one you want and convert from the repo with the single useful file to a new repo containing only that file and all its history
then hg pull from the new single-file-full-history repo into the target repo
hg merge in the target repo and you'll have that file with all it's history
The other option would be to hg export the entire tools repo, use grepdiff (part of difftools) to limit to only one file, and then import into the target repo, but that's crazy.
The short answer is you can't copy a file and its history simply, as stated in this thread:
https://www.mercurial-scm.org/pipermail/mercurial/2009-April/025105.html
I'm relatively new to DVCS and you really have to think of each repo as a self contained package. Not like svn or p4, where you can hang different projects off the root and configure it how you like and do partial repo checkouts. (That said, I really like the flexibility of being able to clone repos quickly to try things out. And being able to commit on a local machine.)
I'm just looking at a similar problem. I've branched a repo to make changes and I only want one file out of one changeset. And it is nice to have the history.
You could look at:
hg cat
This would probably involve writing a script to transfer history, i.e. commit N changesets in the target repo with the hg cat results from the source. Wonder if there is an extension to do this?
You could get the log of the file you want to copy and paste that into a commit comment. It's not in the metadata, but you do have a record and all the hashes etc.
may be
hg export
also can help you.