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A Brief Exposé of
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Jenkins appears to have been what was called Hudson before. It is enhanced, for example to use Git, via plug-ins. Builds can be tagged long after they've completed. Jenkins can distribute builds to multiple computers.
Jenkins is deployed in a server container and configured from its web page.
See http://pkg.jenkins-ci.org/debian/.
wget -q -O - http://pkg.jenkins-ci.org/debian/jenkins-ci.org.key | sudo apt-key add - deb http://pkg.jenkins-ci.org/debian binary/ sudo apt-get update sudo apt-get install jenkins
Remember, it's not Jenkins that does the cloning. Jenkins is really user tomcat6. Here we're on a server named tuonela where Jenkins is running. We "log in" as tomcat6 (shown below) and do the other things in this illustration:
root@tuonela:~# sudo -s -H -u tomcat6 tomcat6@tuonela:~$ alias ll='ls -l' tomcat6@tuonela:~$ mkdir .ssh tomcat6@tuonela:~$ chmod a-rwx .ssh tomcat6@tuonela:~$ chmod u+rwx .ssh tomcat6@tuonela:~$ ls -dal .ssh drwx------ 2 tomcat6 tomcat6 4096 2011-08-10 12:01 .ssh tomcat6@tuonela:~$ cd .ssh tomcat6@tuonela:~/.ssh$ which ssh-keygen /usr/bin/ssh-keygen tomcat6@tuonela:~/.ssh$ ssh-keygen -t rsa -C "Jenkins uses Tomcat" tomcat6@tuonela:~/.ssh$ cp id_rsa.pub [email protected] tomcat6@tuonela:~/.ssh$ vim README.txt In this subdirectory, there is a key pair generated for Jenkins to be able to use Tomcat to clone a Git repository. Don't erase or regenerate the private key, id_rsa, or this will cease working. If you do mess this up, you'll have to regenerate a new pair, rename id_rsa.pub to [email protected], replace the one in in gitolite-admin/keydir, and commit it. -rw------- 1 tomcat6 tomcat6 1679 2011-08-10 11:15 id_rsa -rw-r--r-- 1 tomcat6 tomcat6 401 2011-08-10 11:15 id_rsa.pub -rw-r--r-- 1 tomcat6 tomcat6 401 2011-08-10 11:16 [email protected] Also, do NOT muck with the permissions on this subdirectory. They must remain: drwx------ 2 tomcat6 4096 2011-08-10 11:21 .ssh or most applications will not honor the private key here. tomcat6@tuonela:~/.ssh$ ll total 28 drwx------ 2 tomcat6 tomcat6 4096 2011-08-12 08:38 . drwxrwxrwx 7 root root 4096 2011-08-12 08:38 .. -rw------- 1 tomcat6 tomcat6 1679 2011-08-10 11:15 id_rsa -rw-r--r-- 1 tomcat6 tomcat6 401 2011-08-10 11:15 id_rsa.pub -rw-r--r-- 1 tomcat6 tomcat6 222 2011-08-10 12:01 known_hosts -rw-r--r-- 1 tomcat6 tomcat6 751 2011-08-12 08:38 README.txt -rw-r--r-- 1 tomcat6 tomcat6 401 2011-08-10 11:16 [email protected] tomcat6@tuonela:~/.ssh$ cd .. tomcat6@tuonela:~$ which git tomcat6@tuonela:~$ git clone git@localhost:myproject Cloning into myproject... remote: Counting objects: 269, done. remote: Compressing objects: 100% (229/229), done. remote: Total 269 (delta 83), reused 0 (delta 0) Receiving objects: 100% (269/269), 14.06 MiB | 8.42 MiB/s, done. Resolving deltas: 100% (83/83), done. tomcat6@tuonela:~$ rm -rf myproject/
Actually, the git clone step above did not work until we turned to gitolite-admin to add user tomcat6 and its public key in order for it to be able to clone. For more on this, see Git Administration: Public keys.
Similarly, for MySQL, Jenkins has to be able to reach it. Because a MySQL user need not be an actual user on the host, we'll postulate user jenkins. Initially, we don't have such a user. We'll create it and give it privileges because, for our application, Jenkins needs to run database scripts.
root@tuonela:~# mysql -u jenkins -pjenkins ERROR 1045 (28000): Access denied for user 'jenkings'@'localhost' (using password: YES) root@tuonela:~# mysql -u root -p Enter password: Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 79 Server version: 5.1.54-1ubuntu4 (Ubuntu) Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved. This software comes with ABSOLUTELY NO WARRANTY. This is free software, and you are welcome to modify and redistribute it under the GPL v2 license Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. mysql> GRANT ALL PRIVILEGES ON acme.* TO 'jenkins'@'localhost' IDENTIFIED BY 'jenkins'; mysql> FLUSH PRIVILEGES; Query OK, 0 rows affected (0.00 sec) mysql> quit Bye
The actual configuration file is on the path /usr/share/tomcat6/.jenkins/jobs/<project-name>/config.xml. I tried to use the following method, which did not appear immediately to modify the file on the path above (so I also modified that file, but maybe I just wasn't patient enough or, I needed to bounce Tomcat):
What's sweet about Jenkins is that you can go to where it does the build and launch it yourself to see what goes wrong in its environment. This is particularly useful for early builds while you're shaking the bugs out of your Jenkins set-up. This is where you go:
/usr/share/tomcat6/.jenkins/jobs/acme/workspace
There you'll find a copy of the project Jenkins is continuously building for you. Just type ant. Mind you, if you do this as root, you'll run into a few problems: