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====== Differences ====== This shows you the differences between two versions of the page.

--- guides:git [2010/12/02 16:36]
fishy created
+++ guides:git [2010/12/03 17:40] (current)
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 ====== Some experimentation with git ======
-Server-stuffz, before adding git-http-backend...
+The world has already moved from Centralized Version Control Systems (CVS, SVN et.al) to Distributed Version Control Systems, and it has for long been my intention to play catch-up on that. For me, and for quite a lot of open-source oriented people, the de-facto choice has become Git (http://git-scm.com/), so that is the DVCS I will be focusing on.
+Now, starting to use Git as a single user, or even as multiple contributors when working on a shared system is very straight-forward. In these scenarios, you can live with all source-control happening in the locally available file system.
+The [[http://www.kernel.org/pub/software/scm/git/docs/gittutorial.html|git tutorial]] and [[http://cworth.org/hgbook-git/tour/|Carl Worths "A tour of git"]] will tell you hot to get started with that.
+But, I keep having the desire/need to publish my work more publicly than on my local file system. And coming from a CVSC-background, I have become very used to having external contributors to my code, without having to be a "patch-broker". In addition, I use "VCS-pushing" of code as a form of easily available backup. I have little or no desire to add local Unix-accounts to my web-server to allow for external contributions, and I would like to avoid having to run a separate Daemon process.
+With that basis, I'll describe my foray into git.
+NOTE: For those of you who want to know about using git, and are not interrested in setting up a "svn-to-git-migration-like" server, I have a section on [[#Everyday use of git]] towards the end.
+===== About the environment =====
+I am implementing this using a web-server running Debian Lenny and apache2, hosting all git repositories from a separate virtualhost. My example server hostname will be "git.example.com". My example clients will be a Debian Lenny system and an Ubuntu 9.10.11.12 FIXME.
+===== Installing =====
+===== Attempt one =====
+As you probably get from the heading, I have ended up using a couple of tries getting my setup workable. There is one single reason for this; I started out with the old version of git supplied with Debian Lenny, git 1.5.6.5. But I realized after setting this scenario up, that this version will allow for either anonymous read/write or authenticated read/write. There is no sane way to do anonymous read, authenticated write. To get that functionality, you have to go for git 1.6 or newer, where the more recent [[http://www.kernel.org/pub/software/scm/git/docs/git-http-backend.html|git-http-backend]] is supported.
+There is still an important reason to keep this part of the document. I have not been able, despite serious attempt, troubleshooting, irritation and swearing, to get a git 1.7.1 http-backend based setup working with git-push from a 1.5.6 client! So, if you need to support the Debian Lenny default git version for direct upload (push) over HTTP, use the information in this section.
+On the other hand, if you can live with having to be a patch-broker for users of this older version of git, the [[#Attempt two]] section is for you.
+==== Serverside install ====
+We need to install the git software first, and then prepare a repository for publication via web:
 <code>
 apt-get install git-core
@@ Line 13: / Line 41: @@
 git --bare init
 chown -R www-data.www-data .
+chmod +x hooks/post-update
+</code>
-vim /etc/apache2/sites-available/git.example.com.conf
+Next, we create the required configuration of Apache2's VirtualHost:
-# Show contents of this magic file now.
+<code>
-htpasswd -c /var/www/git.example.com/.passdb/test.git testuser
+cat << EOF > /etc/apache2/sites-available/git.example.com.conf
+<VirtualHost *:80>
+        ServerAdmin webmaster@example.com
+        ServerName  git.example.com
+        DocumentRoot /var/www/git.example.com
-a2ensite git.example.com
+        <Directory /var/www/git.example.com>
+                Options +Indexes
+                AllowOverride None
+                Order allow,deny
+                allow from all
+        </Directory>
+        <Directory /var/www/git.example.com/.passdb>
+                AllowOverride None
+                Order deny,allow
+                deny from all
+        </Directory>
+        <Location /test-repo.git>
+                DAV on
+                AuthType Basic
+                AuthName "Git"
+                AuthUserFile /var/www/git.example.com/.passdb/test.git
+                Require valid-user
+        </Location>
+</VirtualHost>
+EOF
+</code>
+So, this VirtualHost will require:
+  * A htpasswd file for users / groups
+  * The mod_dav module
+  * The mod_dav_fs module
+<code>
+htpasswd -c /var/www/git.example.com/.passdb/test.git testuser
 a2enmod dav
 a2enmod dav_fs
+a2ensite git.example.com
 /etc/init.d/apache2 reload
 </code>
-Client-side stuffs:
+==== Clientside install ====
+First, we need to test that WebDAV works properly. I do this using cadaver, the command line DAV client:
 <code>
 sudo apt-get install cadaver
@@ Line 34: / Line 100: @@
 Password:
 </code>
-vim ~/.netrc
+With that working, it is time to prepare our local git environment. Steps to do here:
+  * Set up automatic authentication for curl/git-push-http
+  * Verify authentication
+  * Install the git program core
+  * Set up your identity as represented with git.
+Change this as needed, in the form I list this, I completely replace any previous content:
+<code>
+cat << EOF > ~/.netrc
+machine git.example.com
+  username testuser
+  password Pa55w0rd
+EOF
 chmod 0600 ~/.netrc
+</code>
+To verify that the .netrc file works, this should not fail:
+<code>
 curl --netrc --location -v http://git.example.com/test-repo.git/HEAD
+</code>
+Install and configure git:
+<code>
 sudo apt-get install git-core
 git config --global user.name "My Name"
 git config --global user.email email@example.com
+</code>
+The setup is now tested with a sample data-set. I did quite a bulk of commands
+to test and troubleshoot my setup, I am listing them here just as much for my own reference as yours :)
+<code>
 cd ~/testcode
 git init
 git add .
 git commit
-git-config remote.upload.url http://testuser@git.example.com/test-repo.git/
+git push http://testuser@git.example.com/test-repo.git/ master
-git push upload master
+git branch
+git branch testing
+git checkout testing
+vim newfile
+git add newfile
+git commit
+git push http://testuser@git.example.com/test-repo.git/ testing
+git ls-remote http://git.example.com/test-repo.git
+mkdir ../testout
+cd ../testout
+git clone http://testuser@git.example.com/test-repo.git
+git branch -a
+git checkout -b testing origin/testing
+</code>
+Note that whenever you need to add a new repository to this kind of setup,
+you will have to update the apache configuration, adding a new Location block.
+===== Attempt two =====
+As I mentioned in the [[#Attempt one]] section, the older versions of git leave a bit to be desired when it comes to access options. But, looking at the results from the [[https://git.wiki.kernel.org/index.php/GitSurvey2010#05._Which_Git_version.28s.29_are_you_using.3F|Git User's Survey 2020]], it seems that maintaining support for these older git-clients should not really be needed. So, I tore the previous setup down, and started with more modern, recent technology. I can live with users of git 1.5.x submitting patches via email, and forcing people who need direct push access into using a newer version.
+==== Serverside install ====
+The serverside install starts out very similar to the previous attempt, but this time differs strongly by pulling in the new (1.7.x) version of git from Lenny Backports.
 <code>
+cat << EOF > /etc/apt/sources.list.d/lenny-backports.list
+deb http://backports.debian.org/debian-backports lenny-backports main contrib non-free
+EOF
+apt-get update
+apt-get install debian-backports-keyring
+apt-get autoremove git-core
+apt-get -t lenny-backports install git
+</code>
-Server fix:
+Preparation of our initial repo is identical to attempt one:
 <code>
-su -
+mkdir /var/www/git.example.com
-su www-data
+mkdir /var/www/git.example.com/.passdb
-cd /var/www/git.example.com/test-repo.git/
-git update-server-info
+cd /var/www/git.example.com
-chmod +w /var/www/git.example.com/test-repo.git/hooks/post-update
+mkdir test-repo.git
+cd test-repo.git
+git --bare init
+chown -R www-data.www-data .
+chmod +x hooks/post-update
 </code>
-Verifying fix and branching:
+The VirtualHost definition for Apache2 is changed somewhat. Most notably,
+it has become longer, and now uses a ScriptAlias to execute CGI instead of relying on WebDAV
+<code>
+<VirtualHost *:80>
+        ServerAdmin webmaster@example.com
+        ServerName  git.example.com
+        DocumentRoot /var/www/git.example.com
+        <Directory /var/www/git.example.com>
+                Options +Indexes +FollowSymLinks +MultiViews +ExecCGI
+                AllowOverride None
+                Order allow,deny
+                allow from all
+        </Directory>
+        <Directory /var/www/git.example.com/.passdb>
+                AllowOverride None
+                Order deny,allow
+                deny from all
+        </Directory>
+        <Directory /usr/lib/git-core>
+                Options None
+        </Directory>
+        <Files /usr/lib/git-core/git-http-backend>
+                Options ExecCGI
+        </Files>
+        CustomLog /var/log/apache2/git.example.com_access.log combined
+        ErrorLog /var/log/apache2/git.example.com_error.log
+        LogLevel warn
+        SetEnv GIT_PROJECT_ROOT /var/www/git.example.com
+        SetEnv GIT_HTTP_EXPORT_ALL
+        SetEnv REMOTE_USER=$REDIRECT_REMOTE_USER
+        ScriptAliasMatch \
+           "(?x)^/(.*/(HEAD | \
+               info/refs | \
+               objects/(info/[^/]+ | \
+                   [0-9a-f]{2}/[0-9a-f]{38} | \
+                   pack/pack-[0-9a-f]{40}\.(pack|idx)) | \
+               git-(upload|receive)-pack))$" \
+           "/usr/lib/git-core/git-http-backend/$1"
+        <LocationMatch "^/.*/git-receive-pack$">
+                AuthType Basic
+                AuthName "Git Access"
+                AuthUserFile /var/www/git.example.com/.passdb/test.git
+                Require valid-user
+        </LocationMatch>
+</VirtualHost>
+</code>
+Now, create the htpasswd file and enable the configuration. Note that I disable
+my old WebDAV support completely here. If you need WebDAV for something unrelated, please make sure you skip those lines :)
+<code>
+a2dismod dav
+a2dismod dav_fs
+htpasswd -c /var/www/git.example.com/.passdb/test.git testuser
+a2ensite git.example.com
+/etc/init.d/apache2 reload
+</code>
+==== Clientside install ====
+This is for Debial Lenny. If you have the older version of git-core installed, start by removing it:
+<code>
+sudo apt-get install git-core
+</code>
+Next, pull in the new version from Lenny Backports:
+<code>
+cat << EOF > /etc/apt/sources.list.d/lenny-backports.list
+deb http://backports.debian.org/debian-backports lenny-backports main contrib non-free
+EOF
+apt-get update
+apt-get install debian-backports-keyring
+apt-get -t lenny-backports install git
+</code>
+Now, configure git global options (your identity):
+<code>
+sudo apt-get install git-core
+git config --global user.name "My Name"
+git config --global user.email email@example.com
+</code>
+Set up a .netrc file to avoid those pesky password prompts. Change this as needed, in the form I list this, I completely replace any previous content:
+<code>
+cat << EOF > ~/.netrc
+machine git.example.com
+  username testuser
+  password Pa55w0rd
+EOF
+chmod 0600 ~/.netrc
+</code>
+The setup is now tested with a sample data-set. Note a difference from the 1.5-series git version, I no longer list the username in the git http URL.
 <code>
 cd ~/testcode
-git branch
+git init
-git branch testing
+git add .
-git checkout testing
-vim newfile
-git add newfile
 git commit
-git push upload testing
+git push http://git.example.com/test-repo.git/ master
+mkdir ../testout
+cd ../testout
+git clone http://git.example.com/test-repo.git
 </code>
+===== A prettyfied web-view: gitweb =====
+Install gitweb from Lenny Backports, and point it to the root of the GIT projects:
+<code>
+apt-get install -t lenny-backports gitweb
+</code>
+Add the following to the Apache2 VirtualHost:
+<code>
+        <Directory /usr/share/gitweb>
+                Options FollowSymLinks +ExecCGI
+                AddHandler cgi-script .cgi
+        </Directory>
+        Alias /gitweb /usr/share/gitweb
+        ScriptAlias / /usr/share/gitweb/index.cgi/
+        <Directory /var/www/git.example.com/.gitweb>
+                AllowOverride None
+                Order deny,allow
+                deny from all
+        </Directory>
+        <Location "/private">
+                AuthType Basic
+                AuthName "Git Private"
+                AuthUserFile /var/www/git.example.com/.passdb/private_users
+                Require valid-user
+        </Location>
+</code>
+<code>
+cat << EOF > /etc/gitweb.conf
+# path to git projects (<project>.git)
+$projectroot = "/var/www/git.example.com";
+# directory to use for temp files
+$git_temp = "/tmp";
+# target of the home link on top of all pages
+#$home_link = $my_uri || "/";
+# html text to include at home page
+# $home_text = "indextext.html";
+$home_text = "/var/www/git.example.com/.gitweb/index.inc";
+# The text on the home link in the breadcrumbs
+$home_link_str = "git.example.com";
+# file with project list
+$projects_list = "/var/www/git.example.com/.gitweb/list";
+# Hide any repo not listed in the $projects_list
+$strict_export = 1;
+# stylesheet to use
+$stylesheet = "/gitweb/gitweb.css";
+# logo to use
+$logo = "/gitweb/git-logo.png";
+# the 'favicon'
+$favicon = "/gitweb/git-favicon.png";
+EOF
+echo "Example text" > /var/www/git.example.com/.gitweb/index.inc
+ls | grep -v private | awk ' { print $1 " Me" }' > /var/www/git.example.com/.gitweb/list
+</code>
+===== Everyday use of git =====
+===== References =====
 http://www.kernel.org/pub/software/scm/git/docs/gittutorial.html
@@ Line 75: / Line 386: @@
 http://www.espace.com.eg/blog/2010/11/10/migrating-from-subversion-to-git/
 http://www.kernel.org/pub/software/scm/git/docs/git-http-backend.html

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