There are situations where you just committed a change in git and just after that realized you made a mistake in the last git commit. If you haven’t pushed that code then the last local changes can be undone with the following command.
git reset --soft HEAD~1
What this does is that it uncommits the last git commit and puts that back in a staged state. That means if you run the git status command then you will see those changes in your working directory. Now you can make further changes to that revision and then commit again.
See the complete documentation about git-reset on the official site.
Recently, I came across a situation where I checked out a git branch and it showed me this message related to detached HEAD state:
You are in 'detached HEAD' state. You can look around, make experimental changes and commit them, and you can discard any commits you make in this state without impacting any branches by performing another checkout.
I guess this happened because the branch that I was checking out was rebased. Otherwise, it usually happens when you checkout a commit with its hash. But in my case, I was checking out a branch. Anyway, this is a special state called “detached HEAD”. While you can commit changes in this state, those commits don’t belong to any branch and will become inaccessible as soon as you check out another branch. But what if you do want to keep those commits?
The answer, unsurprisingly, is to use the “checkout” command again and you can use the same branch again:
git checkout <branch> #now you're in detached head state
# do some work and stage it
git add --all
git commit -m "add some work while in detached head state"
git branch <branch>
git checkout <branch>
OK, this post is a quick one about BitBucket integration. Let’s go!
In your Codenvy workspace go to Profile > Preferences > SSH > VCS and generate a key and give it the name bitbucket.org. This will generate a key for you. Copy this key by viewing it which we will use later on BitBucket.
Now go to BitBucket, select your repository, and then go to repository settings. Under the Access Keys menu click Add Key button. Give a label as bitbucket.org and paste the key copied in the previous step here and save.
Now on the Codenvy project go to the Git menu and add remote. You need to give the SSH URL to your BitBucket repo here. Add it and you can now pull the repo from BitBucket. Awesome!
If you’ve been developing ASP.Net MVC apps lately you might be thinking of some online or cloud-based app hosting platform available as PaaS for Microsoft technologies especially for hosting ASP.Net MVC apps just like OpenShift, Heroku and other platforms are available for technologies like Ruby, Python, PHP, Node.js and even supporting CMS like WordPress. The good news for ASP.Net developers is that there is a PaaS platform available that you might already know. The platform is AppHarbor. AppHarbor runs over Amazon AWS and has some nice features that I won’t go into the details of. If you are interested in knowing how AppHarbor works you can see their page here.
Regardless of whether AppHarbor provides a decent service, new developers might still face some difficulty in deploying their applications to AppHarbor. Especially, if you are developing apps based on new Visual Studio 2015 templates like MVC. There are different ways to deploy but I would follow the below approach which in my opinion is good and provide auto deployment or in other words Continuous Integration (CI).
What do you need?
We will be using the following tools and accounts.
Visual Studio 2015 (any edition, I used the Professional version)
ASP.Net MVC app created from VS2015 MVC template
GitHub repo for the app/project
Local git repo for the app with remote repo set as your GitHub app repo
AppHarbor app
What’s not covered?
Our focus today is the deployment of our ASP.Net MVC app to AppHarbor. Therefore, we won’t be going into the details of how the application is created or its architecture, what’s new in Visual Studio 2015, what is MVC, what is Git and GitHub, and how to connect your GitHub repo to AppHarbor etc. We will assume that you already have all the prerequisites and we will just focus on what problems can we come across during deployment and how to fix them.
Deployment Steps
Initialize a Git repo and connect it with your GitHub repo.
Create the AppHarbor app from your GitHub repo. Whenever we commit/push our changes to our GitHub repo AppHarbor will automatically fetch the latest push and build it. Upon successful build it will deploy the app on its server otherwise it will keep the last successful build. This makes things very easy.
Create an ASP.Net MVC application using the Visual Studio 2015 MVC template.
Add the packages folder to .gitignore
Enable NuGet Package Restore. In VS2015 click Tools>Options and then select NuGet Package Manager and make sure both checkboxes are checked in this section.
In VS2015 right click on the project and click properties, then go to the Build Events tab. In the Post-build event command line text area paste the following command.
if not exist “$(WebProjectOutputDir)\bin\Roslyn” md “$(WebProjectOutputDir)\bin\Roslyn”
start /MIN xcopy /s /y /R “$(OutDir)roslyn\*.*” “$(WebProjectOutputDir)\bin\Roslyn”
Now commit and push your changes to GitHub.
That’s it! AppHarbor will automatically fetch the latest version changes and build it and you can check your AppHarbor application on its URL.
What’s Next?
There are a few things that you need to take care of specially related to security. This MVC app uses SQL Server Compact which isn’t a good option for production-level apps. Secondly, your connection string or password to the database must not be committed to a public GitHub repo.
This post will just give you a smooth start without any difficulties which I faced among other people that you can see in the resources section below.
If you think this was helpful or if I have missed anything please do let me know in the comments below.
create a new directory, open it and perform a git init
to create a new git repository.
checkout a repository
create a working copy of a local repository by running the command git clone /path/to/repository
when using a remote server, your command will be git clone [email protected]:/path/to/repository
workflow
your local repository consists of three “trees” maintained by git. the first one is your Working Directory which holds the actual files. the second one is the Index which acts as a staging area and finally theHEAD which points to the last commit you’ve made.
add & commit
You can propose changes (add it to the Index) using git add <filename> git add *
This is the first step in the basic git workflow. To actually commit these changes use git commit -m "Commit message"
Now the file is committed to the HEAD, but not in your remote repository yet.
pushing changes
Your changes are now in the HEAD of your local working copy. To send those changes to your remote repository, execute git push origin master
Change master to whatever branch you want to push your changes to.
If you have not cloned an existing repository and want to connect your repository to a remote server, you need to add it with git remote add origin <server>
Now you are able to push your changes to the selected remote server
branching
Branches are used to develop features isolated from each other. Themaster branch is the “default” branch when you create a repository. Use other branches for development and merge them back to the master branch upon completion.
create a new branch named “feature_x” and switch to it using git checkout -b feature_x
switch back to master git checkout master
and delete the branch again git branch -d feature_x
a branch is not available to others unless you push the branch to your remote repository git push origin <branch>
update & merge
to update your local repository to the newest commit, execute git pull
in your working directory to fetch and merge remote changes.
to merge another branch into your active branch (e.g. master), use git merge <branch>
in both cases git tries to auto-merge changes. Unfortunately, this is not always possible and results in conflicts. You are responsible to merge those conflicts manually by editing the files shown by git. After changing, you need to mark them as merged with git add <filename>
before merging changes, you can also preview them by using git diff <source_branch> <target_branch>
tagging
it’s recommended to create tags for software releases. this is a known concept, which also exists in SVN. You can create a new tag named 1.0.0by executing git tag 1.0.0 1b2e1d63ff
the 1b2e1d63ff stands for the first 10 characters of the commit id you want to reference with your tag. You can get the commit id by looking at the…
log
in its simplest form, you can study repository history using.. git log
You can add a lot of parameters to make the log look like what you want. To see only the commits of a certain author: git log --author=bob
To see a very compressed log where each commit is one line: git log --pretty=oneline
Or mabe you want to see an ASCII art tree of all the branches, decorated with the names of tags and branches: git log --graph --oneline --decorate --all
See only which files have changed: git log --name-status
These are just a few of the possible parameters you can use. For more, see git log --help
replace local changes
In case you did something wrong (which for sure never happens 😉 you can replace local changes using the command git checkout -- <filename>
this replaces the changes in your working tree with the last content in HEAD. Changes already added to the index, as well as new files, will be kept.
If you instead want to drop all your local changes and commits, fetch the latest history from the server and point your local master branch at it like this git fetch origin git reset --hard origin/master
useful hints
built-in git GUI gitk
use colorful git output git config color.ui true
show log on just one line per commit git config format.pretty oneline
use interactive adding git add -i
create a new branch named “feature_x” and switch to it using