Starting Jenkins

The easiest way to execute Jenkins is through the built in Jetty servlet container. You can execute Jenkins like this:

$ java -jar jenkins.war

Of course, you probably want to send the output of Jenkins to a log file, and if you're on Unix, you probably want to use nohup:

$ nohup java -jar jenkins.war > $LOGFILE 2>&1

Accessing Jenkins

To see Jenkins, simply bring up a web browser and go to URL http://myServer:8080 where myServer is the name of the system running Jenkins.

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Command Line Parameters

Jenkins normally starts up using port 8080. However, if you have other web services starting up you might find that this port is already taken. You can specify a different port by using --httpPort=$HTTP_PORT where $HTTP_PORT is the port you want Jenkins to run on. Other command line parameters include:

Jenkins passes all (or just leading parameters until the first Jenkins-specific parameter?) command line parameters to the Winstone servlet container, so you can get more information by looking at the Winstone Command Line Parameter Reference and jenkinsci/winstone.

A very simple init script

#!/bin/sh

DESC="Jenkins CI Server"
NAME=jenkins
PIDFILE=/var/run/$NAME.pid
RUN_AS=jenkins
COMMAND="/usr/bin/java -- -jar /home/jenkins/jenkins.war"

d_start() {
	start-stop-daemon --start --quiet --background --make-pidfile --pidfile $PIDFILE --chuid $RUN_AS --exec $COMMAND
}

d_stop() {
	start-stop-daemon --stop --quiet --pidfile $PIDFILE
	if [ -e $PIDFILE ]
		then rm $PIDFILE
	fi
}

case $1 in
	start)
	echo -n "Starting $DESC: $NAME"
	d_start
	echo "."
	;;
	stop)
	echo -n "Stopping $DESC: $NAME"
	d_stop
	echo "."
	;;
	restart)
	echo -n "Restarting $DESC: $NAME"
	d_stop
	sleep 1
	d_start
	echo "."
	;;
	*)
	echo "usage: $NAME {start|stop|restart}"
	exit 1
	;;
esac

exit 0

Using HTTPS with an existing certificate

If you're setting up Jenkins using the built-in Winstone server and want to use an existing certificate for HTTPS:

--httpPort=-1 --httpsPort=443 --httpsKeyStore=path/to/keystore --httpsKeyStorePassword=keystorePassword

The keystore should be in JKS format (as created by the JDK 'keytool') and the keystore and target key must have the same password. (Placing the keystore arguments after Jenkins-specific parameters does not seem to work; either they are not forwarded to Winstone or Winstone ignores them coming after unknown parameters. So, make sure they are adjacent to the working --httpsPort argument.)

If your keystore contains multiple certificates (e.g. you are using CA signed certificate) Jenkins might end-up using a incorrect one. In this case you can convert the keystore to PEM and use following command line options:

--httpPort=-1 --httpsPort=443 --httpsCertificate=path/to/cert --httpsPrivateKey=path/to/privatekey

Passing the Command Line Parameters to an instance on a Mac OSX (Currently is Mavericks 10.9.4) that uses launchctl (rather than using Jenkins.jar to start up)

In this example, we set the Jenkins server to listen for HTTPS on port 8443. Note that we do not disable the httpPort by passing in -1. So in this example, your server would answer on both http and https. We also assume that the user has already created the keystore (see the "Using SSL" section from http://wiki.wocommunity.org/display/documentation/Installing+and+Configuring+Jenkins)

sudo launchctl unload /Library/LaunchDaemons/org.jenkins-ci.plist

sudo defaults write /Library/Preferences/org.jenkins-ci httpsPort 8443
sudo defaults write /Library/Preferences/org.jenkins-ci httpsKeyStore /path/to/your/keystore/file
sudo defaults write /Library/Preferences/org.jenkins-ci httpsKeyStorePassword <keystore password>

sudo launchctl load /Library/LaunchDaemons/org.jenkins-ci.plist

Using HTTP/2

With Java 8 (should be included per default in Java 9), you need to include alpn boot jar in the bootclasspath. The alpn boot jar depends on your jvm version. Have a look here https://www.eclipse.org/jetty/documentation/current/alpn-chapter.html#alpn-versions to figure which version to use.

You can download it from (with alpn boot version 8.1.12.v20180117): https://repo.maven.apache.org/maven2/org/mortbay/jetty/alpn/alpn-boot/8.1.12.v20180117/alpn-boot-8.1.12.v20180117.jar

Then you have to include it on jvm start:

java -Xbootclasspath/p:alpn-boot-8.1.12.v20180117.jar -jar target/jenkins.war --http2Port=9090

Configuring https certificates with Windows

Creating a certificate for use within Jenkins. This used a stock Jenkins 1.612 installation on Windows Server 2008 R2 Standard 64-bit. This creates a certificate signed by a Certificate Authority such as Digicert, if making your own certificate skip steps 3, 4, and 5.

This process utilizes Java's keytool, however you do not have to perform a separate Java installation if you don't need it. Jenkins packages a JRE with it when you do the installation, located in C:\Program Files (x86)\Jenkins\jre\bin 

Step 1: Create a new keystore on your server. This will place a 'keystore' file in your current directory.

C:\Program Files (x86)\Jenkins\jre\bin>keytool -genkeypair -keysize 2048 -keyalg RSA -alias jenkins -keystore keystore
Enter keystore password:
Re-enter new password:
What is your first and last name?
[Unknown]: server-name.your.company.com
What is the name of your organizational unit?
[Unknown]: Your City
What is the name of your organization?
[Unknown]: Your company name
What is the name of your City or Locality?
[Unknown]: Your city
What is the name of your State or Province?
[Unknown]: Your State
What is the two-letter country code for this unit?
[Unknown]: US
Is CN=server-name.your.company.com, OU=Your City, O=Your company name, L=Your City, ST=Your State, C=US correct?
[no]: yes

Enter key password for <jenkins>
(RETURN if same as keystore password):

Step 2: Verify the keystore was created (your fingerprint will vary)

C:\Program Files (x86)\Jenkins\jre\bin>keytool -list -keystore keystore
Enter keystore password:

Keystore type: JKS
Keystore provider: SUN

Your keystore contains 1 entry

jenkins, May 6, 2015, PrivateKeyEntry,
Certificate fingerprint (SHA1): AA:AA:AA:AA:AA:AA:AA:AA:AA:AA:AA:AA:AA:AA:AA:AA:AA:AA:AA:AA

Step 3: Create the certificate request.  This will create a 'certreq.csr' file in your current directory.

C:\Program Files (x86)\Jenkins\jre\bin>keytool -certreq -alias jenkins -keyalg RSA -file certreq.csr -ext SAN=dns:server-name,dns:server-name.your.company.com -keystore keystore
Enter keystore password:

Step 4: Use the contents of the certreq.csr file to generate a certificate from your certificate provider. Request a SHA-1 certificate (SHA-2 is untested but will likely work). If using DigiCert, download the resulting certificate as Other format  "a .p7b bundle of all the certs in a .p7b file".

Step 5: Add the resulting .p7b into the keystore you created above.

C:\Program Files (x86)\Jenkins\jre\bin>keytool -import -alias jenkins -trustcacerts -file response_from_digicert.p7b -keystore keystore
Enter keystore password:
Certificate reply was installed in keystore

Step 6: Copy the 'keystore' file to your Jenkins secrets directory. On a stock installation, this will be at

C:\Program Files (x86)\Jenkins\secrets

Step 7: Modify the <arguments> section of your C:\Program Files (x86)\Jenkins\jenkins.xml file to reflect the new certificate. Note: This example disables http via --httpPort=-1 and places the server on 8443 via --httpsPort=8443.
 

<arguments>-Xrs -Xmx256m -Dhudson.lifecycle=hudson.lifecycle.WindowsServiceLifecycle -jar "%BASE%\jenkins.war" --httpPort=-1 --httpsPort=8443 --httpsKeyStore="%BASE%\secrets\keystore" --httpsKeyStorePassword=your.password.here</arguments>

Step 8: Restart the jenkins service to initialize the new configuration.

net stop jenkins
net start jenkins

Step 9: After 30-60 seconds, Jenkins will have completed the startup process and you should be able to access the website at https://server-name.your.company.com:8443; Verify the certificate looks good via your browser's tools.  If the service terminates immediately, there's an error somewhere in your configuration. Useful error information can be found in:

C:\Program Files (x86)\Jenkins\jenkins.err.log
C:\Program Files (x86)\Jenkins\jenkins.out.log

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