Getting Started With the TDS: Local Test Server Setup

What This Section Covers

This section covers basic installation and configuration of Tomcat, Java JDK and the TDS for a local test server:

• Installing Java and Tomcat
• Tomcat Directory Structure: Quick Tour
• Running Tomcat
• Tomcat Log Files
• Tomcat (Server-Level) Configuration Files
• Deploying the TDS
• Tomcat manager Application
• Next Steps: Where To Go From Here

No prior knowledge of Tomcat, Java, or the TDS needed.

Installing Java and Tomcat

System requirements

• Oracle Java 8 (latest version)
• Apache Tomcat 8.x

While there are different distributors of Java and servlet containers, Unidata develops, uses and tests the THREDDS Data Server using Oracle Java and the Apache Tomcat servlet container.

Installing Java

1. Download current Java SE Developer Kit (JDK) from Oracle. Use the latest 1.8 version of the JDK.

At the time of this workshop, that is version Java SE 8u51. We will be using the Linux x64-bit tar.gz file:

jdk-8u51-linux-x64.tar.gz

2. Install the JDK as per the Oracle installation instructions.

Copy the binary tar.gz file into the installation directory (/usr/local/tds/ in this example):

$ pwd
/usr/local/tds
$ cp Downloads/jdk-8u51-linux-x64.tar.gz .

$ ls -l
drwxr-xr-x  2 tds workshop     4096 Jul 15 10:33 Desktop
drwxr-xr-x  2 tds workshop     4096 Jul 15 10:33 Documents
drwxr-xr-x  2 tds workshop     4096 Jul 22 17:29 Downloads
-rw-r--r-- 1 tds workshop 96316511 Jul 15 09:30 jdk-8u51-linux-x64.tar.gz
drwxr-xr-x  2 tds workshop     4096 Jul 15 10:33 Music
drwxr-xr-x  2 tds workshop     4096 Jul 15 10:33 Pictures
drwxr-xr-x  2 tds workshop     4096 Jul 15 10:33 Public
drwxr-xr-x  3 tds workshop     4096 Jul 15 10:45 tdsMonitor
drwxr-xr-x  2 tds workshop     4096 Jul 15 10:33 Templates
-rwxrwxr-x  1 tds workshop 27866303 Jul 15 10:02 toolsUI-4.3.18.jar
drwxr-xr-x  2 tds workshop     4096 Jul 15 10:33 Videos

Unpack the archive file:

$ tar zxvf jdk-8u51-linux-x64.tar.gz

This will extract the JDK in the installation directory:

$ ls -l
drwxr-xr-x  2 tds workshop     4096 Jul 15 10:33 Desktop
drwxr-xr-x  2 tds workshop     4096 Jul 15 10:33 Documents
drwxr-xr-x  2 tds workshop     4096 Jul 23 14:40 Downloads
drwxr-xr-x 8 tds workshop 4096 Jun 5 22:07 jdk1.8u51
-rw-r--r--  1 tds workshop 96316511 Jul 15 09:30 jdk-8u51-linux-x64.tar.gz
drwxr-xr-x  2 tds workshop     4096 Jul 15 10:33 Music
drwxr-xr-x  2 tds workshop     4096 Jul 15 10:33 Pictures
drwxr-xr-x  2 tds workshop     4096 Jul 15 10:33 Public
drwxr-xr-x  3 tds workshop     4096 Jul 15 10:45 tdsMonitor
drwxr-xr-x  2 tds workshop     4096 Jul 15 10:33 Templates
-rwxrwxr-x  1 tds workshop 27866303 Jul 15 10:02 toolsUI-4.3.18.jar
drwxr-xr-x  2 tds workshop     4096 Jul 15 10:33 Videos

Troubleshooting

Depending on your OS you may need install either the 32-bit or 64-bit version of the JDK. But, we really, really, really recommend you use a 64-bit OS if you're planning to run the THREDDS Data Server.

Installing Tomcat

1. Download current version of the Tomcat 8 servlet container.

At the time of this workshop, that is version 8.0.24. We will be using the binary tar.gz file:

apache-tomcat-8.0.24.tar.gz

2. Install Tomcat as per the Apache Tomcat installation instructions.

Copy the binary tar.gz file into the installation directory (/usr/local/tds/ in this example):

$ pwd
/usr/local/tds

$ ls -l
-rw-r--r-- 1 tds workshop 7955948 Jul 15 09:35 apache-tomcat-8.0.24.tar.gz
drwxr-xr-x  2 tds workshop     4096 Jul 15 10:33 Desktop
drwxr-xr-x  2 tds workshop     4096 Jul 15 10:33 Documents
drwxr-xr-x  2 tds workshop     4096 Jul 23 14:40 Downloads
drwxr-xr-x  8 tds workshop     4096 Jun  5 22:07 jdk1.8u51
-rw-r--r--  1 tds workshop 96316511 Jul 15 09:30 jdk-8u51-linux-x64.tar.gz
drwxr-xr-x  2 tds workshop     4096 Jul 15 10:33 Music
drwxr-xr-x  2 tds workshop     4096 Jul 15 10:33 Pictures
drwxr-xr-x  2 tds workshop     4096 Jul 15 10:33 Public
drwxr-xr-x  3 tds workshop     4096 Jul 15 10:45 tdsMonitor
drwxr-xr-x  2 tds workshop     4096 Jul 15 10:33 Templates
-rwxrwxr-x  1 tds workshop 27866303 Jul 15 10:02 toolsUI-4.3.18.jar
drwxr-xr-x  2 tds workshop     4096 Jul 15 10:33 Videos

Unpack the archive file:

$ tar xvzf apache-tomcat-8.0.24.tar.gz

This will create a Tomcat directory:

$ ls -l
drwxr-xr-x 9 tds workshop 4096 Jul 15 09:37 apache-tomcat-8.0.24
-rw-r--r-- 1 tds workshop  7955948 Jul 15 09:35 apache-tomcat-8.0.24.tar.gz
drwxr-xr-x  2 tds workshop     4096 Jul 15 10:33 Desktop
drwxr-xr-x  2 tds workshop     4096 Jul 15 10:33 Documents
drwxr-xr-x  2 tds workshop     4096 Jul 23 14:40 Downloads
drwxr-xr-x  8 tds workshop     4096 Jun  5 22:07 jdk1.8u51
-rw-r--r--  1 tds workshop 96316511 Jul 15 09:30 jdk-8u51-linux-x64.tar.gz
drwxr-xr-x  2 tds workshop     4096 Jul 15 10:33 Music
drwxr-xr-x  2 tds workshop     4096 Jul 15 10:33 Pictures
drwxr-xr-x  2 tds workshop     4096 Jul 15 10:33 Public
drwxr-xr-x  3 tds workshop     4096 Jul 15 10:45 tdsMonitor
drwxr-xr-x  2 tds workshop     4096 Jul 15 10:33 Templates
-rwxrwxr-x  1 tds workshop 27866303 Jul 15 10:02 toolsUI-4.3.18.jar
drwxr-xr-x  2 tds workshop     4096 Jul 15 10:33 Videos

Tomcat Directory Structure: Quick Tour

Exploring the Tomcat directory structure

1. Examine the Tomcat directory structure, aka ${tomcat_home}.

Move into ${tomcat_home} and do a long listing:

$ cd apache-tomcat-8.0.24
$ ls -l
drwxr-xr-x 2 tds workshop  4096 Jul 15 09:37 bin
drwxr-xr-x 2 tds workshop  4096 Jul  2 01:59 conf
drwxr-xr-x 2 tds workshop  4096 Jul 15 09:37 lib
-rw-r--r-- 1 tds workshop 56812 Jul  2 01:59 LICENSE
drwxr-xr-x 2 tds workshop  4096 Jul  2 01:57 logs
-rw-r--r-- 1 tds workshop  1192 Jul  2 01:59 NOTICE
-rw-r--r-- 1 tds workshop  8826 Jul  2 01:59 RELEASE-NOTES
-rw-r--r-- 1 tds workshop 16262 Jul  2 01:59 RUNNING.txt
drwxr-xr-x 2 tds workshop  4096 Jul 15 09:37 temp
drwxr-xr-x 7 tds workshop  4096 Jul  2 01:59 webapps
drwxr-xr-x 2 tds workshop  4096 Jul  2 01:57 work

2. Familiarize yourself with the following important directories.

bin/

• Contains startup.sh, shutdown.sh and other scripts/programs.
• The *.sh files (for Unix systems) are functional duplicates of the *.bat files (for Windows systems).

conf/

• Server-wide Tomcat configuration.
• You will modify server.xml and tomcat-users.xml to adjust logging, authentication and access control, enable SSL, etc.
• Web applications can override some server-wide settings in their own configuration files (more about that later).

webapps/

• Contains web applications directories and WAR files.
• This is where we will be putting the TDS web application.
• You will also be using the manager application that comes with Tomcat during this workshop.

logs/

• Tomcat log files are here by default.
• This is one of the directories you will be looking for log files (the TDS logs elsewhere by default).
• The log files should be your first stop for troubleshooting Tomcat and TDS issues. (Hint, hint.)
• Logs files may contain useful information for assessing the security of your system.
• You will become very familiar with the Tomcat-generated catalina.out, catalina.yyyy-mm-dd.log and localhost_access_log.yyyy-mm-dd.log files by the end of this workshop.

Running Tomcat

Starting & stopping Tomcat

1. Tomcat isn't currently running so we need to start it up.

Run the startup.sh script in the Tomcat bin/ directory:

$ pwd
/usr/local/tds/apache-tomcat-8.0.24

$ bin/startup.sh

2. Verify Tomcat is running.

Look and see if you have a Tomcat process running:

$ ps -ef | grep tomcat
tds      21912     1 29 09:39 pts/1    00:00:02 /usr/bin/java -Djava.util.logging.config.file=/usr/local/tds/apache-tomcat-8.0.24/conf/logging.properties -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager -Djava.endorsed.dirs=/usr/local/tds/apache-tomcat-8.0.24/endorsed -classpath /usr/local/tds/apache-tomcat-8.0.24/bin/bootstrap.jar:/usr/local/tds/apache-tomcat-8.0.24/bin/tomcat-juli.jar -Dcatalina.base=/usr/local/tds/apache-tomcat-8.0.24 -Dcatalina.home=/usr/local/tds/apache-tomcat-8.0.24 -Djava.io.tmpdir=/usr/local/tds/apache-tomcat-8.0.24/temp org.apache.catalina.startup.Bootstrap start
tds      21933 21675  0 09:39 pts/1    00:00:00 grep tomcat

Open a new browser window/tab and go to http://localhost:8080/ to verify Tomcat is running:



3. See if you can shutdown Tomcat.

Run the shutdown.sh script in the Tomcat bin/ directory:

$ bin/shutdown.sh

Setting $JAVA_HOME, $JAVA_OPTS, $CATALINA_BASE, and $CONTENT_ROOT

We are going to create a file called setenv.sh in the Tomcat bin/ directory to:

• allow Tomcat to reference/find the location of $JAVA_HOME and $CATALINA_BASE) during startup and shutdown;
• increase the amount of memory allocated to the JVM to enhance performance by setting $JAVA_OPTS; and
• add additional settings to the JVM via $JAVA_OPTS to enable more advanced services we will be learning about later on in this workshop.

1. Create the setenv.sh file.

Using your favorite text editor (gedit, vi, emacs, etc.), create a new file called setenv.sh in the Tomcat bin/ directory:

$ pwd
/usr/local/tds/apache-tomcat-8.0.24

$ cd bin
$ vi setenv.sh

Add the following information and save your setenv.sh file:

#!/bin/sh
#
# ENVARS for Tomcat
#
export CATALINA_HOME="/usr/local/tomcat"

export CATALINA_BASE="/usr/local/tomcat"

export JAVA_HOME="/usr"

# TDS specific ENVARS
#
# Define where the TDS content directory will live
#   THIS IS CRITICAL and there is NO DEFAULT - the
#   TDS will not start without this.
#
CONTENT_ROOT=-Dtds.content.root.path=/usr/local/tomcat/content

# set java prefs related variables (used by the wms service, for example)
JAVA_PREFS_ROOTS="-Djava.util.prefs.systemRoot=$CATALINA_HOME/content/thredds/javaUtilPrefs \
                  -Djava.util.prefs.userRoot=$CATALINA_HOME/content/thredds/javaUtilPrefs"

#
# Some commonly used JAVA_OPTS settings:
#
NORMAL="-d64 -Xmx4096m -Xms512m -server -ea"
HEAP_DUMP="-XX:+HeapDumpOnOutOfMemoryError"
HEADLESS="-Djava.awt.headless=true"

#
# Standard setup.
#
JAVA_OPTS="$CONTENT_ROOT $NORMAL $MAX_PERM_GEN $HEAP_DUMP $HEADLESS $JAVA_PREFS_ROOTS"

export JAVA_OPTS

Settings

Whenever possible, Unidata recommends -Xmx4096m (or more) for 64-bit systems.

The parameters we pass to $JAVA_OPTS:

• -Xms is the initial and minimum allocated memory of the JVM (for performance).
• -Xmx the maximum allocated memory of the JVM (for performance).
• -server tells the Hostspot compiler to run the JVM in "server" mode (for performance).
• -Djava.awt.headless=true is needed to prevent graphics rendering code from assuming a graphics console exists. Without this, WMS code will crash the server in some circumstances.
• -Djava.util.prefs.systemRoot=$CATALINA_BASE/content/thredds/javaUtilPrefs allows the java.util.prefs of the TDS WMS to write system preferences to a location that is writable by the Tomcat user.

Looking Ahead

You will learn more about the TDS Web Map Service (WMS) later on in this tutorial.

2. Implement your changes by restarting Tomcat.

Restart Tomcat and examine the output generated to the terminal window by the startup script:

$ ./startup.sh
Using CATALINA_BASE:   /usr/local/tds/apache-tomcat-8.0.24
Using CATALINA_HOME:   /usr/local/tds/apache-tomcat-8.0.24
Using CATALINA_TMPDIR: /usr/local/tds/apache-tomcat-8.0.24/temp
Using JRE_HOME: /usr/local/tds/jdk1.8u51
Using CLASSPATH:       /usr/local/tds/apache-tomcat-8.0.24/bin/bootstrap.jar:/usr/local/tds/apache-tomcat-8.0.24/bin/tomcat-juli.jar

Did you notice any difference in the what is being reported to STDOUT during startup?

Take a look at the running Tomcat process to see the new $JAVA_OPTS settings:

$ ps -ef | grep tomcat
tds      22007     1  9 09:44 pts/1    00:00:02 /usr/local/tds/jdk1.8u51/bin/java -Djava.util.logging.config.file=/usr/local/tds/apache-tomcat-8.0.24/conf/logging.properties -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager -Xmx4096m
  -Xms512m -server -Djava.awt.headless=true -Djava.util.prefs.systemRoot=/usr/local/tds/apache-tomcat-8.0.24/content/thredds/javaUtilPrefs -Djava.endorsed.dirs=/usr/local/tds/apache-tomcat-8.0.24/endorsed -classpath /usr/local/tds/apache-tomcat-8.0.24/bin/bootstrap.jar:/usr/local/tds/apache-tomcat-8.0.24/bin/tomcat-juli.jar -Dcatalina.base=/usr/local/tds/apache-tomcat-8.0.24 -Dcatalina.home=/usr/local/tds/apache-tomcat-8.0.24 -Djava.io.tmpdir=/usr/local/tds/apache-tomcat-8.0.24/temp org.apache.catalina.startup.Bootstrap start
tds      22030 21675  0 09:44 pts/1    00:00:00 grep tomcat

Environment Variables

For more information on the environment variable prerequisites used by Tomcat, consult ${tomcat_home}/bin/catalina.sh (or catalina.bat) file.

What allows us to create the setenv.sh file and have its contents read? (Hint: have a look at the catalina.sh file in the Tomcat bin/ directory at lines 24 and 133).

Troubleshooting

• Do not forget include the 'm' in your -Xms and -Xmx settings.
• You may have allocated too much memory for the JVM settings if Tomcat fails to start and you get the following error reported in the Tomcat log catalina.out:

Error occurred during initialization of VM
Could not reserve enough space for object heap

• Likewise, if there is an error with your JVM memory allocation syntax in the setenv.sh file, it will be reported to catalina.out:

Error occurred during initialization of VM
Incompatible minimum and maximum heap sizes specified

• If you intend to use WMS and see something like the following in reported in catalina.out:

May 25, 2010 6:28:22 PM java.util.prefs.FileSystemPreferences syncWorld
WARNING: Couldn't flush system prefs: java.util.prefs.BackingStoreException: /etc/.java/.systemPrefs/org create failed.

You will need to set the java.util.prefs.systemRoot system property in $JAVA_OPTS to a location that is writable by the user that Tomcat, e.g.:

#!/bin/sh
#
# ENVARS for Tomcat and TDS environment
#
JAVA_HOME="/usr/local/tds/jdk1.8u51"
export JAVA_HOME

JAVA_OPTS="-Xmx4096m -Xms512m -server -Djava.awt.headless=true -Djava.util.prefs.systemRoot=$CATALINA_BASE/content/thredds/javaUtilPrefs"
export JAVA_OPTS

CATALINA_BASE="/usr/local/tds/apache-tomcat-8.0.24"
export CATALINA_BASE

Tomcat Log Files

Tomcat logs/

1. Look at the different types of log files being generated in the Tomcat logs/ directory.

Move into the logs/ directory to see the type of information being logged:

$ pwd
/usr/local/tds/apache-tomcat-8.0.24/webapps
$ cd ../logs

$ ls -l
-rw-r--r-- 1 tds workshop 5637 Jul 15 09:51 catalina.2013-07-15.log
-rw-r--r-- 1 tds workshop 5637 Jul 15 09:51 catalina.out
-rw-r--r-- 1 tds workshop    0 Jul 15 09:39 host-manager.2013-07-15.log
-rw-r--r-- 1 tds workshop 2811 Jul 15 09:52 localhost.2013-07-15.log
-rw-r--r-- 1 tds workshop    0 Jul 15 09:39 localhost_access_log.2013-07-15.txt
-rw-r--r-- 1 tds workshop    0 Jul 15 09:39 manager.2013-07-15.log

Do you see a correspondence between some of the web applications in the Tomcat webapps/ directory and the naming of certain log files?

Is there a difference in the information being logged to catalina.out versus catalina.yyyy-mm-dd.log?

Are some log files more verbose than others?

2. Examining catalina.out.

Open another terminal window (hereafter referred to as terminal #2) and run the following command in the new terminal:

$ tail -f /usr/local/tds/apache-tomcat-8.0.24/logs/catalina.out

In your original terminal window, start/stop and start Tomcat and watch what is being logged to catalina.out in the terminal #2 window.

Is it only errors messages being reported to catalina.out?

Things to know about catalina.out

• Tomcat System.out and System.err gets appended to catalina.out.
• catalina.out can quickly grow large if the hosted web applications are not specifically catching and logging System.out and System.err to designated files.
• catalina.out is not automatically rotated in Tomcat.
• You should employ an outside log rotation program (e.g., logadm or logrotate) to rotate catalina.out.
• It is good practice to archive and remove old catalina.out files and other log files out of the Tomcat logs/ on a regular basis.
• On Windows, the catalina.out file is not automatically created. Instead only the catalina.yyyy-mm-dd.log files are used. These have equivalent content.

Tomcat (Server-Level) Configuration Files

About server.xml

• XML file (well-formed syntax is important).
• Tomcat's main configuration file.
• Changes to server.xml do not take effect until Tomcat is restarted.
• Where we make changes to enhance TDS security.

Important elements in server.xml

1. Examine the Elements in server.xml.

Move into the Tomcat conf/ directory and examine the server.xml file:

$ pwd
/usr/local/tds/apache-tomcat-8.0.24/logs
$ cd ../conf

$ less server.xml

Reference the table below to see how the server.xml elements relate to configuring TDS (mouse-over the element for a description):

Tag Name	Instances	How it relates to the TDS
<Server>	1...1	Not modified unless you want to change the port number Tomcat listens for a SHUTDOWN command. (Enabled by default.)
<GlobalNamingResources>	0...*	Needed to contain the UserDatabase that corresponds to the UserDatabaseRealm used to authenticate users. (Enabled by default.)
<Resource>	0...*	Editable user database (tomcat-users.xml) used by UserDatabaseRealm to authenticate users. (UserDatabaseRealm Resource enabled by default.)
<Service>	1...*	Not modified unless you wish to establish more than one service. (Catalina Service enabled by default.)
<Connector>	1...*	Used to establish HTTP and SSL connections. Also will communicate with an web server for proxying requests. (HTTP connector enabled by default on port 8080.)
<Engine>	1...1	Not modified unless you specify a Host other than localhost. (Enabled by default.)
<Realm>	0...*	The UserDatabaseRealm uses the UserDatabase configured in the global JNDI Resource. (UserDatabaseRealm enabled by default.)
<Valve>	0...*	The RemoteAddrValve is used to filter access to the TDS based on IP address. (NOT enabled by default. You will need to add this if you want to use IP Filtering.)
<Host>	1...*	Not modified unless you specify a Host other than localhost. (localhost enabled by default.)
<Realm>	0...*	We use the MemoryRealm to configuring Tomcat to use digested passwords. (NOT enabled by default. You will need to add this if you want to use digested passwords.)
<Valve>	0...*	We modify the AccessLogValve to customize the access logs generated by Tomcat. (NOT enabled by default. You will need to add this if you want to enable access logging.)

About tomcat-users.xml

• XML file (well-formed syntax is important).
• Stores user names, passwords and roles.
• Changes to tomcat-users.xml do not take effect until Tomcat is restarted.
• What the TDS uses for user authentication and access control.

Important elements in tomcat-users.xml

1. Examine the Elements in tomcat-users.xml.

Open the tomcat-users.xml file:

$ pwd
/usr/local/tds/apache-tomcat-8.0.24/conf

$ less tomcat-users.xml

Reference the table below to see how the tomcat-users.xml elements relate to configuring TDS (mouse-over the element for a description):

Tag Name	Instances	How it relates to the TDS
<tomcat-users>	1...1	Not modified. (The only tag you get by default.)
<role>	1...*	You will have at least two of these: one for the Tomcat manager application and one for the TDS. (You will need to add if you want to enable role-based authentication.)
<user>	1...*	You will need to create an entry for each user who needs access to the Tomcat manager application and/or the restricted areas of the TDS. (You will need to add if you want to enable user authentication.)

Deploying the TDS

About WAR files

• WAR is short for Web ARchive.
• By default, Tomcat will automatically unpack the WAR distribution into directory of the same name upon deployment.
• Note: the unpacked directory is overwritten each time a new WAR file is deployed.

Downloading & deploying thredds.war

1. Download the TDS WAR file from Unidata's web site.

We will be using the current TDS 4.6.2 version for this workshop:

thredds.war

2. Deploy the TDS in Tomcat.

Put thredds.war in the Tomcat webapps/ directory:

$ pwd
/usr/local/tds/apache-tomcat-8.0.24/bin
$ cd ../webapps

$ mv ~/thredds.war .
$ ls -l
drwxr-xr-x 13 tds workshop     4096 Jul 15 09:37 docs
drwxr-xr-x  6 tds workshop     4096 Jul 15 09:37 examples
drwxr-xr-x  5 tds workshop     4096 Jul 15 09:37 host-manager
drwxr-xr-x  5 tds workshop     4096 Jul 15 09:37 manager
drwxr-xr-x  3 tds workshop     4096 Jul 15 09:37 ROOT
-rw-r--r--  1 tds workshop 33218655 Jul 15 09:50 thredds.war

3. Confirm the TDS has been deployed.

If Tomcat is already running, wait a couple of seconds after placing the WAR file in the Tomcat webapps/ and then verify the thredds.war file was unpacked:

$ ls -l
drwxr-xr-x 13 tds workshop     4096 Jul 15 09:37 docs
drwxr-xr-x  6 tds workshop     4096 Jul 15 09:37 examples
drwxr-xr-x  5 tds workshop     4096 Jul 15 09:37 host-manager
drwxr-xr-x  5 tds workshop     4096 Jul 15 09:37 manager
drwxr-xr-x  3 tds workshop     4096 Jul 15 09:37 ROOT
drwxr-xr-x 8 tds workshop 4096 Jul 15 09:51 thredds
-rw-r--r--  1 tds workshop 33218655 Jul 15 09:50 thredds.war

Go to http://localhost:8080/thredds/ in your browser to verify the TDS has been deployed:



4. Confirm the creation of the TDS content/ directory.

Move into ${tomcat_home} and do a long listing:

$ pwd
/usr/local/tds/apache-tomcat-8.0.24/webapps
$ cd ..

$ ls -l
drwxr-xr-x 2 tds workshop  4096 Jul 15 09:51 bin
drwxr-xr-x 3 tds workshop  4096 Jul 15 09:55 conf
drwxr-xr-x 3 tds workshop 4096 Jul 15 09:52 content
drwxr-xr-x 2 tds workshop  4096 Jul 15 09:37 lib
-rw-r--r-- 1 tds workshop 56812 Jul  2 01:59 LICENSE
drwxr-xr-x 2 tds workshop  4096 Jul 15 09:39 logs
-rw-r--r-- 1 tds workshop  1192 Jul  2 01:59 NOTICE
-rw-r--r-- 1 tds workshop  8826 Jul  2 01:59 RELEASE-NOTES
-rw-r--r-- 1 tds workshop 16262 Jul  2 01:59 RUNNING.txt
drwxr-xr-x 2 tds workshop  4096 Jul 15 09:55 temp
drwxr-xr-x 8 tds workshop  4096 Jul 15 09:51 webapps
drwxr-xr-x 3 tds workshop  4096 Jul 15 09:39 work

Troubleshooting

• Any error in the TDS deployment will be reported in the catalina.out file of the Tomcat logs/ directory.
• Be sure you have downloaded and deployed the correct version of the TDS (version 4.3.18 snapshot for this workshop). The TDS version number will appear in the blue bar at the bottom of TDS catalog pages.

Tomcat manager Application

About the manager application

• "Free" web application that comes with Tomcat distribution.
• Lives in the manager directory in the Tomcat webapps/ directory.
• Allows Tomcat administrators to deploy, undeploy, or reload web applications such as the TDS without having to shut down and restart Tomcat.
• Provides server status statistics for the JVM and each connector you have configured in server.xml.

Accessing the Tomcat manager application

Attempt to access the Tomcat manager application in your browser: http://localhost:8080/manager/html/. You will be prompted to login via BASIC authentication, which will end in failure since we do not yet have permission to access the manager application:

Granting access to the manager application

1. Modify tomcat-users.xml to add role and user elements.

Using your favorite editor, open ${tomcat_home}/conf/tomcat-users.xml:

$ vi tomcat-users.xml

Between the <tomcat-users> tags, add a role element and specify the rolename attribute as manager:

<tomcat-users>
    <role rolename="manager-gui"/>
</tomcat-users>

Now add a new user by adding a user element. Create a username and password for the new user and specify manager-gui as one of the roles (in this example we are creating a user called 'admin' with a corresponding password of 'secret'):

<tomcat-users>
    <role rolename="manager-gui"/>
    <user username="admin" password="secret" roles="manager-gui"/>   
</tomcat-users>

2. Restart Tomcat and log into the manager application.

Thinking ahead

To gain access to restricted parts of the TDS, you will perform the same steps you used to grant yourself access to the manager application.

Attempt to access the manager application again (http://localhost:8080/manager/html/), this time logging in using the name and password specified in tomcat-users.xml:



Voilà! You should have access to the manager application.

Troubleshooting

• Check the XML syntax in tomcat-users.xml to make sure it is well-formed and without error.
• Did you restart Tomcat after you made your changes to tomcat-users.xml?
• Any errors will be reported in the Tomcat logs/catalina.out file.

Deploying the TDS using the manager application

1. Use the manager application to undeploy the TDS.

Find the TDS in the list of web application on the Applications page. Stop and then Undeploy the TDS:



List the contents of the Tomcat webapps/ directory to verify that both thredds.war and the unpacked thredds/ directory have been removed:

$ pwd
/usr/local/tds/apache-tomcat-8.0.24/conf
$ cd ../webapps

$ ls -l
drwxr-xr-x 13 tds workshop     4096 Jul 15 09:37 docs
drwxr-xr-x  6 tds workshop     4096 Jul 15 09:37 examples
drwxr-xr-x  5 tds workshop     4096 Jul 15 09:37 host-manager
drwxr-xr-x  5 tds workshop     4096 Jul 15 09:37 manager
drwxr-xr-x  3 tds workshop     4096 Jul 15 09:37 ROOT

2. Deploy the TDS using the manager application.

Upload the TDS WAR file using the Deploy section of the manager application:



Confirm the deployment went as planned by accessing the TDS using your browser: http://localhost:8080/thredds/

Next Steps: Where To Go From Here

You're not finished yet

• If you plan to deploy the TDS in a production environment you will need to follow the best practices outlined in the Production server overview section of the tutorial to finish hardening your server environment.
• The Basic TDS Configuration and TDS Configuration Catalogs sections of this tutorial covers the TDS configuration files, configuration options and TDS catalog structure.