I ended up writing this snippet after I found out that deploying a git branch with vlad wasn’t as easy as it should’ve been…

I assumed the Vlad documentation was right, so I put the branch name in the revision variable (located in config/deploy.rb):

   1  set :revision,              'branch_name'

But then I got this error when executing rake vlad:deploy:

   1  git checkout: updating paths is incompatible with switching branches/forcing
   2  Did you intend to checkout 'branch_name' which can not be resolved as commit?

I managed to solve the problem by using the SHA1 hash of the branch instead of the branch name, but that only worked for the current revision:

   1  set :revision,              'd34360870be6536992e6d45bb0aa72eca31e14443'

So after some googling I found this post at scie.nti.st, which made my day because it has the following examples of how to deploy tags and branches with git and Vlad:

   1  # Deploy the latest code, this the default
   2  set :revision, "HEAD" 
   3  
   4  # Deploy branch "origin/branch_name"
   5  set :revision, "origin/branch_name"
   6   
   7  # Deploy tag "1.0"
   8  set :revision, "1.0"

Note that you have to push the branch to the remote server before running rake vlad:deploy:

   1  git push origin branch_name

Although Git is one of the better source code managers it has a major drawback if you need to install it from the sources – it’s makefile doesn’t have an uninstall target as defined in the GNU coding standards. Therefore you might find your system screwed over when you want to uninstall or upgrade after installing from sources. This is a workaround that is sufficient enough to make me break my rule of not installing software outside of package management.

Also see the snippet for an alias for the make command first.

Prequisities

   1  sudo apt-get install asciidoc xsltproc xmlto xstow bzip2 build-essential zlib1g-dev tcl8.4

Installation

   1  cd /tmp
   2  wget http://kernel.org/pub/software/scm/git/git-1.5.5.1.tar.bz2
   3  tar xjvf git-1.5.5.1.tar.bz2
   4  sudo mv git-1.5.5.1 /usr/src
   5  sudo ln -s /usr/src/git-1.5.5.1 /usr/src/git
   6  cd /usr/src/git
   7  ./configure --prefix=/usr/local/stow/git
   8  make all doc
   9  sudo make install install-doc
  10  cd /usr/local/stow
  11  cat << EOF > /tmp/xstow.ini
  12  # this is the xtow configuration file
  13  # see xstow.ini(5) for details
  14  
  15  # list of links that will be handled as normal directories
  16  [traverse-links] 
  17  keep-targets = true      # add targets of the links to the keep-dirs section
  18  link = /usr/local/tmp
  19  link = /usr/local/var
  20  link = /usr/local/man
  21  link = /usr/local/share
  22  link = /usr/local/share/man
  23  link = /usr/local/doc
  24  link = /usr/local/info
  25  add-if-target = /*       # automatic add all absolute links
  26  
  27  # directories that never should be removed
  28  [keep-dirs]
  29  dir = /usr/local/bin
  30  dir = /usr/local/sbin
  31  dir = /usr/local/lib
  32  dir = /usr/local/include
  33  dir = /usr/local/share
  34  
  35  [matches]
  36  ignore = *~      # emacs
  37  ignore = core    # core file
  38  ignore = core.*  # new style
  39  ignore = CVS     # CVS directories
  40  ignore-regex = [0]+README.*
  41  
  42  # make other stow dirs public
  43  [stow-dirs]
  44  dir = /usr/local/local/stow
  45  dir = /usr/local/local/stow2
  46  
  47  [debug]
  48  module = ALL
  49  level  = 0
  50  
  51  [config-files]
  52  in-home = yes
  53  in-stow-dir = yes
  54  in-other-stow-dirs = yes
  55  file = /etc/xstow.ini
  56  file = /usr/local/local/etc/xstow.ini
  57  
  58  [links]
  59  absolute-paths = false
  60  EOF
  61  sudo mv -i /tmp/xstow.ini .
  62  sudo xstow git

Uninstallation

   1  cd /usr/local/xstow
   2  xstow -D git
   3  sudo rm -rf /usr/local/stow/git

Kind of makes one appreciate the work done by package maintainers, doesn’t it?

In this snippet- Christian explains how to fix the empty ident error using a bleeding edge git. In older git versions this must be done manually. So if you get this error…

   1  *** Environment problem:
   2  *** Your name cannot be determined from your system services (gecos).
   3  *** You would need to set GIT_AUTHOR_NAME and GIT_COMMITTER_NAME
   4  *** environment variables; otherwise you won't be able to perform
   5  *** certain operations because of "empty ident" errors.
   6  *** Alternatively, you can use user.name configuration variable.
   7  
   8  fatal: empty ident  <.....@......com> not allowed

... then add the following parameters to your ~/.bashrc file and source it with . ~/.bashrc (or relogin, alternatively):

   1  export GIT_AUTHOR_NAME="Marko Haapala"
   2  export GIT_COMMITTER_NAME="Marko Haapala"

Git is a good alternative to Mercurial, and of course SVN or CVS if you’re still using stone age tools, so in this post I’ll show you how to compile, install and use git with Rails.

Installing git on Mac OS X

First compile and install git:

   1  cd /usr/local/src
   2  wget http://kernel.org/pub/software/scm/git/git-1.5.4.4.tar.bz2
   3  tar jxvf git-1.5.4.4.tar.bz2
   4  cd git-1.5.4.4
   5  make prefix=/usr/local all
   6  make prefix=/usr/local test && echo $?
   7  sudo make prefix=/usr/local install

Installing git on Debian

On a Debian installation install git by first executing the following commands:

$ sudo apt-get install git-core

Note that the package name is git-core not git.

If you want the latest and greatest version, you first need to install the dependencies (note that you can leave out tk and expat):

   1  sudo apt-get install curl
   2  sudo apt-get install libcurl3
   3  sudo apt-get install libcurl3-dev
   4  sudo apt-get install tk8.4
   5  sudo apt-get install cpio expat
   6  sudo apt-get install zlib
   7  sudo apt-get install build-essential
   8  sudo apt-get install zlib1g-dev 
   9  sudo apt-get install asciidoc
  10  sudo apt-get install xmlto

Then compile and install:

   1  NO_EXPAT=yes NO_SVN_TESTS=yes NO_IPV6=yes NO_TCLTK=yes make -j2 prefix=/usr all
   2  NO_EXPAT=yes NO_SVN_TESTS=yes NO_IPV6=yes NO_TCLTK=yes make -j2 prefix=/usr install

Configuring git

Run these commands to tell git your name and email:

   1  git config --global user.name "u name"
   2  git config --global user.email x@x.com

Otherwise, you might get this error:

   1  *** Environment problem:
   2  *** Your name cannot be determined from your system services (gecos).
   3  *** You would need to set GIT_AUTHOR_NAME and GIT_COMMITTER_NAME
   4  *** environment variables; otherwise you won't be able to perform
   5  *** certain operations because of "empty ident" errors.
   6  *** Alternatively, you can use user.name configuration variable.
   7  
   8  fatal: empty ident  <........@........com> not allowed
   9  fatal: The remote end hung up unexpectedly

If you like colorized command output execute these commands:

   1  git config --global color.diff auto
   2  git config --global color.status auto
   3  git config --global color.branch auto

Using git

If all goes well, change to your project directory and run the following commands:

   1  git init

This creates the git repository, so we’re now ready to start adding files to it, but first we need to create the git ignore file, which tells git to ignore certain files completely:

   1  cat <<EOF<<EOF > .gitignore 
   2  config/database.yml
   3  db/*.sqlite3
   4  log/*.log
   5  tmp/**/*
   6  .DS_Store
   7  doc/api
   8  doc/app
   9  EOFEOF

By default git doesn’t add empty directories—sucks if you ask me—so we’ll create a dummy file in all empty directories with the find and touch commands:

   1  find . \( -type d -empty \) -and \( -not -regex ./\.git.* \) -exec touch {}/.gitignore \; 

Importing files

We’re now ready to start adding and commiting files, so without thinking execute:

   1  git add .
   2  git commit -m 'initial import'

This creates the git repository, adds and commits all files that are in the current folder.

Using remote repositories

If you’re like me you’ll want to use a remote repository, so let’s continue the exercise by creating the repository folder on the remote server (Note that commands are executed on the remote server from now on):

   1  mkdir /var/lib/git/repositories/project_name

We want the folder to be accessible by users belonging to the git group only:

   1  addgroup git
   2  chown root.git /var/lib/git/repositories/project_name
   3  chmod 770 /var/lib/git/repositories/project_name

Now add yourself—or the user you’ll be using to connect to the remote server—to the git group:

   1  usermod -a -G git your_username

Alternatively create a new user:

   1  useradd -g git your_username

Now we’re finally ready to copy the local repository to the remote server, which is done with the scp command (Note that commands are executed locally again from now on):

   1  scp -rp .git user@server://var/lib/git/repositories/project_name

To let git know that this repository exists we’ll use the git remote command:

   1  git remote add project_name ssh://server/var/lib/git/repositories/project_name

This adds the information to .git/config, which might be good to have a quick look at.

Note that if you’re using a non-standard SSH port you need to add the following to your ~/.ssh/config file:

   1  Host server
   2    Port 1234

Commit files and push them to the remote server

Now change a file and commit and push the changes to the remote server:

   1  git commit -m "Me be sleepy"
   2  git push project_name

If you get an error such as this it means you need to install git:

   1  $ git push project_name
   2  username@server's password: 
   3  sh: git-receive-pack: command not found
   4  fatal: The remote end hung up unexpectedly

That’s all…

Miscellaneous problems

error: unable to create temporary sha1 filename ./objects/obj_FUu2jb: Permission denied

Resources

http://jointheconversation.org/railsgit

http://devblog.michaelgalero.com/2007/12/17/my-git-notes-for-rails/

http://railscasts.com/episodes/96

http://groups.google.com/group/rails-oceania/browse_thread/thread/2c8611dc93917952/e175f72310823547

http://www.kernel.org/pub/software/scm/git/docs/tutorial.html

http://scie.nti.st/2007/11/14/hosting-git-repositories-the-easy-and-secure-way