Jenkins: Improve the format of the email 4

Like many people, we use Jenkins to perform several tasks automatically.
Jenkins is an open source automation server, it provides hundreds of plugins to support building, deploying and automating any project.

One of the features of Jenkins is the option to send an email to the user under certain circumstances, e.g. after a build was complete.
The default layout of those emails is not so pretty, so we did some changes to it.
Note: below we present how to make the changes apply to the whole system, if you do not want to do that, you could apply these changes to individual projects only.

Using an administrative account, click on Manage Jenkins option on the left menu and in the new screen click on Configure System on the right column.
These actions will take you to the configuration page of your Jenkins installation (e.g. http://jenkins:8080/configure).

Scroll down to the category Extended E-mail Notification.

  1. From the drop down menu, change the value of Default Content Type to HTML (text/html).
  2. Update the value of Default Subject to [$BUILD_STATUS] - $PROJECT_NAME - Build # $BUILD_NUMBER ($BUILD_ID). We prefer to have the build status first (like a tag).
  3. In the box named Default Content enter the following block of data:
    Check console <a href="$BUILD_URL">output</a> to view full results.<br/>
    If you cannot connect to the build server, check the attached logs.<br/>
    Following is the last 100 lines of the log.<br/>
    <pre style='line-height: 22px; display: block; color: #333; font-family: Monaco,Menlo,Consolas,"Courier New",monospace; padding: 10.5px; margin: 0 0 11px; font-size: 13px; word-break: break-all; word-wrap: break-word; white-space: pre-wrap; background-color: #f5f5f5; border: 1px solid #ccc; border: 1px solid rgba(0,0,0,.15); -webkit-border-radius: 4px; -moz-border-radius: 4px; border-radius: 4px;'>
    ${BUILD_LOG, maxLines=100, escapeHtml=true}

The email you will receive after a successful execution will be similar to the one below:

Subject: [Successful] - banana - Build # 77 (77)

Press the Apply button to save the changes.

You will notice that in the email we mention the following: If you cannot connect to the build server, check the attached logs..
To enable the option to attach the logs, you need to configure your project itself.
Select your project from the main screen and then click on Configure on the left column.

Scroll down to Post-build Actions section.

From the Add post-built action drop down list select Editable Email Notification.

A new block will appear in the page.
Set the value of Attach Build Log drop down to Compress and Attach Build Log and then hit the Apply button.

Back Up Jenkins instance except for workspace and build logs

Our Jenkins setup has a lot of cool features and configuration.
It has ‘project-based security’, it has parametrized projects, multiple source code management blocks per project and fairly extensive tests implemented with several build steps.
Of course, we do not want to lose them, so we make backups often.
The commands we use for the backup are the following.

 backup_folder="$HOME/jenkins/`date +%F`";
 mkdir -p "$backup_folder";
 (cd "$jenkins_folder"/jobs/; find . -mindepth 3 -type d -regex '.*/[0-9]*$' -print) | sed 's|./|jobs/|' | sudo rsync --archive --exclude 'workspace/*' --exclude-from=- "$jenkins_folder" "$backup_folder";

Explanation of commands:

  • In backup_folder="$HOME/jenkins/`date +%F`"; we used the $HOME variable instead of the tilde ~ as this would create a folder in the current directory called ~ instead of creating a new folder called jenkins in the home directory.
  • mkdir -p "$backup_folder"; instructs mkdir to create all parent folders needed to create our destination folder.
  • (cd "$jenkins_folder"/jobs/; find . -mindepth 3 -type d -regex '.*/[0-9]*$' -print) navigates to the directory of jenkins before performing the search, this way the result file names will be relative to the installation location which we need later to pass to rsync.
    Then we search for all folders which their name is numeric and they at least on depth 3. We filter by depth as well to avoid matching folders directly in the jobs folder.
  • sed 's|./|jobs/|' replaces the prefix ./ with jobs/ to match the relative path from where rsync will work from
  • sudo rsync --archive --exclude 'workspace/*' --exclude-from=- "$jenkins_folder" "$backup_folder"; it will copy everything from $jenkins_folder to the folder $backup_folder while excluding the data in workspace and the folders matched from find (the job build folders).
    --exclude-from=- instructs rsync to read from stdin the list of files to exclude.

Installing Jenkins on Red Hat (CentOS 7 64bit) distributions

Following the official guides:

We tried to install Jenkins using the RPM repositories.

sudo yum install java -y;
sudo wget -O /etc/yum.repos.d/jenkins.repo;
sudo rpm --import;
sudo yum install jenkins -y;

Unfortunately, that resulted in an error:

warning: /var/cache/yum/x86_64/7/jenkins/packages/jenkins-2.19.2-1.1.noarch.rpm: Header V4 DSA/SHA1 Signature, key ID d50582e6: NOKEY

Public key for jenkins-2.19.2-1.1.noarch.rpm is not installed

Apparently, sudo rpm --import; failed silently and it did not import the key.

To verify, we executed rpm -qa gpg-pubkey* to display a list of all keys installed for RPM verification. From that list we wanted to see if any of the keys was the one needed by jenkins which should end with the value d50582e6. Since none of them matched, we tried to manually re-import it which failed again.

Our Solution

Our solution, although ugly, was to disable  PGP verification in the file /etc/yum.repos.d/jenkins.repo.


That was enough to allow us to install the package using:

sudo yum install jenkins -y;

Finally, we started jenkins using sudo service jenkins start;.

Logs from failed installation

[bytefreaks@localhost ~]$ sudo yum install jenkins -y
[sudo] password for bytefreaks:
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
* base:
* extras:
* updates:
Resolving Dependencies
--> Running transaction check
---> Package jenkins.noarch 0:2.19.2-1.1 will be installed
--> Finished Dependency Resolution

Dependencies Resolved

Package                                                Arch                                                  Version                                                     Repository                                              Size
jenkins                                                noarch                                                2.19.2-1.1                                                  jenkins                                                 66 M

Transaction Summary
Install  1 Package

Total size: 66 M
Installed size: 67 M
Downloading packages:
warning: /var/cache/yum/x86_64/7/jenkins/packages/jenkins-2.19.2-1.1.noarch.rpm: Header V4 DSA/SHA1 Signature, key ID d50582e6: NOKEY

Public key for jenkins-2.19.2-1.1.noarch.rpm is not installed