Code Merging with offshore team - different source control repositories - merge

Summary:
We used to be on SVN and working with offshore team building our automation.
We periodically merged to keep us in sync(local and offshore team). Like every other day or so.
Local team switched to GIT while offshore continued their work on SVN. Security policies, still flushing out new git processes and such...
We have 2 different projects now that are off sync.
Question:
Now that we want them to move to GIT so that we can sync up I can think of couple of options once their code is in GIT:
Manual merge (its been a month, but I think I can do it). Manually copy files over, build fix etc.
Have offshore team rename their files a little so that GIT thinks its a new file and then manually resolve some duplicates perhaps.
There shouldn't be many
Any advise would be much appreciated.

The manual merge should be a straightforward solution:
Compare and merge two different folders, one with your Git repo, one with the latest SVN HEAD revision.
Once the merge is done, you can send them back a Git bundle (one file), which they can clone and start working from, within their own Git cloned repo.

Related

Eclipse Egit - is it possible to compare commits on different projects?

At the new workplace where I work, in the past, the main project was split in two branches, because different customers began to have very different requirements. A pretty common scenario I guess.
Now, I'am not a developer but a sysadmin, and not an expert of git, but I was wondering if in these cases usually is the correct approach to use branches, because in my understanding a fork would be more adapt.
What the CTO is asking me to do, is to migrate this branch, into a new git repository. But he also says that he wants to still be able to perform comparisons between commits, therefore (in eclipse + egit) to right-click on workspace > team > show in history > select the commits he wants to compare > click on compare to each other. I believe that these requirements conflict to each other, so my main question is: is it possible to compare commits of different git repositories?
My second question is, if a project with the same core that starts to require different features, should be branched forked or moved to a new repository?
Hope my question is not too broad
There is no concept called fork in Git. Git hosting services, such as Github or Gitlab, provide such a feature. As far as Git is concerned, a fork is essentially just a branch. And also, every clone of a repository - even local repositories - are essentially forks.
To split up your repository into two repositories that have a fork relationship, first just create a clone of the repository. And then delete branches in both repositories that refer to commits of the now-other-repository.
The usual approach to compare forks is to add a remote to the other remote. This is possible in your case too, since you have common commits in both repositories, before the forking-point. More on remotes here: What is "git remote add ..." and "git push origin master"?

Looking for a way to sync Perforce <-> Git

Our team is looking to migrate our perforce server over to Git. Is there a way to sync check-ins from a branch in our Github Server back to Perforce to keep them in sync? I have been looking at git-p4 and there seems to be lots of documentation of how to sync Perforce -> Git but not the other way around. I would ideally like to have it syncing both ways perforce <-> git, is that possible with p4-git?
Perforce GitFusion can do this, but the developer would have to push changes to the GitFusion server instead of the github server.
For most of the time, merge conflicts were sorted out automatically. Perforce was the "master". People submitting from Perforce always had their change go straight through. People submitting from git would have their change submitted via this process:
lock master git repo
fetch upstream p4 changes
rebase against upstream p4
submit to p4 if that all went ok
That still left a very small window between (3) and (4) where someone in Perforce land could submit a conflicting change to the same files. But in practice that only happened a couple of times, over the course of several years of probably hundreds of commits per week.
In those two cases I went in and manually patched things up which was a bit clunky. I think you could just automatically discard the problematic change quite easily, but in the end, switching to git entirely made this problem go away.
Git-p4 is designed such that the git repository is initialized with data imported from Perforce. After this initial import bidirectional communication between git and Perforce repositories is fully supported, with the exception of branches/merges that have limited support.
To import updates from Perforce to git:
git p4 sync
To submit changes from git to Perforce:
git p4 submit
For more details regarding git-p4 configuration please consult its documentation.
Update: I would always advise to test any flows in temporary repositories before deploying.
In the past I setup something like this. I had a gitolite repo and a p4 server. Changes pushed to the gitolite repo would be picked up by a cron job and turned into P4 commits (via git-p4 submit). Similarly, changes submitted to p4 would be picked up by the same cron job and synced back to git (via git p4 rebase).
There were two git repos involved: the gitolite repo that normal git developers committed to, and a separate git-p4 based repo where the git-p4 operations took place.
I had a fairly small shell script to co-ordinate everything. The main tricky areas were:
locking: you have to forcibly rebase the gitolite repo so you need some way to ensure developers don't lose changes when this happens (I used a lock file).
Merge conflicts. Very occasionally two people would edit the same section of a file in P4 and git at the same time.
I have faced this problem myself and as far as I know there's nothing of the kind.
In my case I have to basically:
Create a patch for the changes in Git: git diff sha1..sha2 > mypatch.diff
Make a list of the affected files: git diff --name-only sha1..sha2 > files.list
Apply the patch in the P4 repo: git apply mypatch.diff
Reconcile changes in P4: for each file in files.list; p4 reconcile $file; done
Edit your P4 change list and then submit it (I'm sure this can be automated too but I haven't had the need for it).
I have a couple of scripts that help me with this, you can find them here: https://github.com/pgpbpadilla/git-p4-helpers#sharing-changes-git-p4
I have been using this workflow for ~6mo and it works for most cases.
Caveats
This creates a single change lists for all commits in the sha range (a..b).

Using GitHub and Eclipse to pull code

I have a repo on GitHub here.
I have pushed to this repo from two different machines, so now one machine is current and another has outdated code. Right now, I am on the machine with outdated code, and I want to pull in the master/HEAD/whatever from GitHub.
And then I get to stare at this:
I do not want to do something stupid like delete the project from Eclipse and then pull in all the code from GitHub.
Can someone please help me merge/synchronize the projects? This is as simple as it sounds.
Unfortunately, this is what happens when I click "Pull" on the above menu:
Would someone also explain what the difference is between Pull, Merge, Fetch and Synchronize?
eGit doesn't know, which remote branch you want to pull from.
If you create your local branch based on a remote tracking branch, then the key is generated automatically. Otherwise you have to create it yourself:
branch.master.merge=refs/heads/master
branch.master.remote=origin
where master stands for the branchname, in the key it's your local branch, in the value it's the branch in the remote repository. Place that in the repository-specific configuration file %repositorypath%\.git\config
As for the terms:
merge: join two or more development histories together
fetch: download objects and refs from another repository
pull: fetch from and merge with another repository or local branch
sync: allows you to compare 2 branches
In general, I urge you to read eGit user guide, where you can get even better understanding of Git and eGit. It can be found at http://wiki.eclipse.org/EGit/User_Guide

How to avoid getting git errors/conflicts on untouched files?

I often see the below errors on doing git pull on totally untouched files which I am NOT working on.
Pull is not possible because you have unmerged files
It is clear the conflicted files have changed in the git repo. But I don't understand why git pull cannot over-write on these untouched files - which I've not touched?
What can I or my team do to avoid getting these errors?
Edited -
Along with the solution I want to understand why the errors are coming.
Just to make clear, the other team members are working on other files (say xyz). And I am working on a separate set of files having no dependency on xyz files. So if I pull the repo changes after a long time with no changes from my side in xyz, why the conflicts in those files?
use git diff to see problem files
look at this git cheat shets for usefull commands
http://www.cheat-sheets.org/saved-copy/git-cheat-sheet.pdf
http://jan-krueger.net/wordpress/wp-content/uploads/2007/09/git-cheat-sheet-v2-back.svg
There are some tips from my own experience. i'm not sure whether they're 100% corerect)
Split work with your team on paralel threads. Try not to work in the same files.
Try to avoid situations when 2 or more persons are adding new files simalteniously. When one added new files others should make pull as soon as possible
the last but not least - make git push very often. this will keep your project git up to date
Since git pull does not pull individual files, it's git merge phase will stop for manual correction of any merge conflicts. git merge and/or git pull (and by nature of the fact that git pull is essentially git fetch followed by git merge) is an all-or-nothing operation - you either successfully merge the changes introduced on both (or all) of the branches you are merging together, or you don't merge any of them. The catch in that is when conflicts arise that must be manually resolved - but in that situation, you are in an in-between state, having neither completed and committed the merge nor rolled it back to your previous state.
The message you are getting implies that you have previously done a git pull or a git merge, which stopped in the middle, requesting that you manually resolve some conflicts, which you have not yet done, but have rather continued on doing other stuff, and are now trying to do another git pull / git merge without ever having completed the first one.
Take a look at git status, and follow the suggested directions for either resolving your in-progress merge issues or resetting back to a not-in-the-middle-of-a-merge state.

Git/Mercurial locally ontop of local cvs checkout

I have read :
"Best practices for using git with CVS"
"How to export revision history from mercurial or git to cvs?"
, and neither suit my needs.
At work we use a remote CVS repo. Access to this repo is handled via eclipse CVS tools, and in-house eclipse plugins that are built ontop of team tools for eclipse. This means we can't move to a better vcs.
However I would like to use Git on my local machine (to enable personal branching) such that I can accomplish the following:
Create branches in Git and then once finished and merged back into my local trunk, commit back to the cvs repo using the eclipse team tools etc.
My plan is something along the following lines:
Copy the checked out files to another folder [gitRepo].
Create a master git repo in gitRepo
Branch in gitRepo and make changes.
Commit to gitRepo
Copy gitRepo back to checked out files
Sync with remote cvs.
I was planning on using eGit for eclipse however I believe that the CVS and .git files will compete for ownership of the versioning.
Are there any tools or suggested work flows to help me manage this? Also how well does Git play with CVS files. And vice versa since I don’t want them to infect each other.
The reason the former links are of no use is they commit straight to the cvs repo from the git repo and this worries me as I do not wish to infect the cvs repo by accident.
It should also be said that changes in the GitRepo do not need to persist into the CVS repo, for example I don’t need to see every push to the git repo reflected in the remote CVS.
~Thanks for reading.
You perfectly can create a git repo directly within a CVS workspace (much like directly within any other VCS tool.
Make sure git will ignore any .cvs resources, and make sure CVS will ignore the .git.
Any Git commit won't be directly reflected in CVS.
The only trick is for Eclipse to display only Git or only CVS informations and label decoration.
For that I would configure two different Eclipse perspectives in which I will de-activate one or the other VCS tool.
I have done exactly this at work and I found the following practices helpful:
Keep any one (master in my case) branch always in sync with CVS. Do not use this branch for your development. Periodically update this branch to get the changes made by the rest of the team. If these changes are relevant to your current work do a merge master from your dev (or any other appropriate) branch.
When you are ready to check in to CVS switch to the master branch and merge the changes from the appropriate branch (dev, feature etc. as appropriate). Run your tests!
You employer most likely will keep a back up of the CVS repos. You will have to find a way to keep your git repo backed up. One way is to add a mirror repository in a Dropbox folder and use a post-commit hook to update it after each commit.
Before you leave work switch to the master branch. I once made the mistake of running CVS up -d on a dev branch in the morning and ended up quite confused. Adding a script to automatically switch to master before updating helps.