deep dive into git with team foundation server
TRANSCRIPT
Martin Woodward Edward ThomsonPrincipal Program Manager Senior Software Engineer
Deep dive into Git with Team Foundation Server
3-590
tinyurl.com/proalm12
We work hereand here
A comprehensive ALM offeringTeam
Foundation Service
Planning SCM Work Item Tracking Continuous Deployment Build Automation Feedback
Management
Centralized Version Control
(TFVC)
Strengths Best for
Modern source-control approaches
Server Workspaces
Local Workspaces
DistributedVersion Control (Git)
• Scales to very large codebases
• Fine level permission control• Allows usage monitoring
• Large integrated codebases• Control and auditability over
source code down to the file level
• Offline editing support• Easy to edit files outside
Visual Studio or Eclipse
• Medium-sized integrated codebases
• A balance of fine-grained control with reduced friction
• Full offline experience• Complete repository with
portable history• Simplified branching model
• Modular codebases• Integrating with open source• Highly distributed teams
Git fully integrated into Visual Studio and TFS
Fully integratedGit support
Team Foundation Server/ServiceProject 2
Issues
Project
MgmtBuild
Git SCC Provider
Project 1
Issues
Project
MgmtBuild
Git
3rd Party XCodeEclipseShell
…
3rd Party Eclipse
Shell… TFVC
……
TFS SCC Provider
Team Explorer
TFVC Object Model
Local Repo
LibGit2 / LibGit2Sharp
Other Remote
Git Repo
Git-TF
Version control using Git with Visual Studio and TFSDemo
Install Git for Windows Install PoshGit Install Windows Credential
Helper
Installing the perfect command linehttp://aka.ms/GitCL
Pick the middle one:
Tip: Installing Git for Windowsfriends don’t let friends use Git bash…
The Git repositoryDeep Dive
History
1 2 3
1 2 3 4
5
My repository
Bob’s repository
5
6
History is “flattened” to resemble output from regular git log
History in Visual Studio
How are commit IDs generated? Can’t be monotonically increasing without a server to arbitrate A cryptographic hash (SHA1) of the contents of the commit
History
1 2 3 4
5
64d2460a 6d36faa
fc1de8e
56b1b9f8b58f71aab6f14
CommitsContain meta-data
commit 4d2460a...
Parent commit: 6d36faa...
Author: Display Name <[email protected]> Timestamp
Committer: Display Name <[email protected]> Timestamp
CommitsRepresent the entire repository
\file1.txt
blob feb8b81... file1.txt
tree 09fc4b44...
commit 4d2460a...
\file1.txt\file2.txt
blob 095ee29... file2.txt
blob feb8b81... file1.txt
tree 1a58993...
commit 6d36faa...
Commits are immutable Since they are the hash of the contents, changing the content changes
the hash Create a new commit that contains the old data and the modifications
Commit amend Updates only the latest commit
Dangerous if you have published commits Other users are making changes based on that commit
Rewriting history
You can remove the ability to “force push” to TFSRestricting ability to push history re-writes
CommitsDemo
Author and Committer default to data in Git Settings:
git config --global user.name “Martin Woodward“ git config --global user.email “[email protected]"
Git Settings
gitignore file specifies which files get ignored from the repo by default
Best stored in the repo
Go to Git Settings in VS to create a default one
Ignoring stuff with .gitignore
Git configuration can be stored in the repo and be path specific using .gitattributes
Commonly controls Which files are treated as binary Merge strategies Line ending conversion
Git Attributes
git config --global core.autocrlf=true
A note on line endings
Git does not track renames Commits are a snapshot of the entire repository No additional metadata about deltas between commits
Git guesses renames Compare deleted files to added files Similar files are deemed “renames”
Heuristic approach to renames is more accurate than relying on user input.
Renames
Branches
4d2460a 6d36faa
fc1de8e
56b1b9f8b58f71aab6f14
bobs
mine
HEAD
Branches
4d2460a 6d36faa
fc1de8e
56b1b9f8b58f71aab6f14
bobs
mine
HEAD
45dc20f
BranchesDemo
Exist at the repository level A branch applies to the entire repository Unlike most centralized version control tools where branches
exist inside the repository
Exceptionally lightweight Implemented as a pointer to a commit in the graph Exist only in the local repository until they’re explicitly shared Encourages feature branching
Branches
MergesMerging two commits
4d2460a 6d36faa
fc1de8e
8b58f71aab6f14
bobs
mine
HEAD
MergesMerging two commits
4d2460a 6d36faa
fc1de8e
8b58f71aab6f14
bobs
mine
HEAD
833831f
MergesFast-forwards
4d2460a 6d36faa
fc1de8e
aab6f14
feature
master
HEAD
MergesFast-forwards
4d2460a 6d36faa
fc1de8e
aab6f14
feature
master
HEAD
Merging and dealing with conflicts in Visual StudioDemo
Based on pack filesOnly 3 methods: info_refs: What are the current branch pointers? receive_pack: Push upload_pack: Fetch
Bottlenecks. Generally limited by client bandwidth
Git protocol
TFS Git object data in SQLRepository Existence and Ownership
tbl_GitRepository (RepositoryId, Name, CreationDate, State, TeamProjectUri)
Git Ref Pointerstbl_GitRef (RepositoryId, Name, ObjectId, IsDefaultBranch)
Git Push Logtbl_GitPush (PushId, PusherId, PushTime)
Git Ref Logtbl_GitRefLog (PushId, Name, OldObjectId, NewObjectId)
Stored in SQL for on-premises TFS
In Visual Studio Online, stored in Azure Blob storage
TFS Git object data in SQL/Azure BLOB
Git is bad at certain things
Reorganize data to answer path questions Done by a job that runs on each push UI works without data until it is available
Index things like author, committer, change typesCache is fully re-buildableLink to work items on push in a low pri job
TFS solution: Metadata cache in SQL
Git is different Don’t force change on a team, give them choice Build out set of internal advocates and expertise via PoC’sCan use Git-TF or Git-SVN etc to migrate history Do you really need to migrate ALL history? Does the historical repo need to be the working one?If moving to Git, MOVE to GitFor large repos: Remove binary dependencies first (NuGet is your friend) Componentize code before migrating
Adopting Git
Options for users to access Visual Studio Online3) New cloud-only monthly user
plans
2) Included for MSDN subscribers
Mix & match: pick the right MSDN subscription or user plan for each team member’s needs. New monthly user plans can be used to complement teams of MSDN subscribers.
Increased value to existing and new MSDN subscribers. User plans purchased via Windows Azure.
1) Completely free for small teams
FREE: 5 users.FREE: 60 minutes Cloud Build per month.
FREE: 5 users.Additional users $20/month.
All users $45/month.Max 10 per account with this plan.Includes use of the VS Pro IDE.All users $60/month.
Choice in source code workflows Integrates the leading DVCS solution into the leading ALM suite Use centralized or distributed modes and always get the full integrated
ALM capabilities of TFS
Choice in development processes Pick Agile, CMMI, or Scrum processes or create your own Tooling to support best of breed practices regardless of your development
methodology
Choice in platforms Target the platform of your choice from the development environment of your
choice
Microsoft ALM supports choice
for MSDN Ultimate subscribers
Go to http://msdn.Microsoft.com/specialoffers
SPECIAL OFFERSPartner Program
Your Feedback is ImportantFill out an evaluation of this session and help shape future events. Scan the QR code to evaluate this session on your mobile device. You’ll also be entered into a daily prize drawing!
© 2014 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.
Exist at the repository level A tag applies to the entire repository Unlike most centralized version control tools where tags
contain a subset of the repository
Similar to branches. Implemented as a pointer to a commit in the grap Exist only in the local repository until they’re explicitly shared
Tags
Tags
release-0.1
release-0.2
4d2460a 6d36faa
fc1de8e
8b58f71aab6f14
bobs
mine
HEAD
833831f
Tags
release-0.1
release-0.2
4d2460a 6d36faa
fc1de8e
8b58f71aab6f14
bobs
833831f
mine
HEAD
7bcf452
RebaseRebasing a commit
4d2460a 6d36faa
fc1de8e
8b58f71aab6f14
bob
mine
HEAD
RebaseRebasing a commit
4d2460a 6d36faa
fc1de8e e4e1fb3
aab6f14
bob
mine
HEAD
Sync with Visual StudioSync is the equivalent of: 1. fetch2. merge3. push
“Pushed By” tracked by TFS