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3.16 Installing Nitro Web Services

This topic contains instructions on how to install Nitro Web Services.

Do the following in the order presented:

Open Necessary Ports
Install MongoDB
Install and Configure Nitro Web Services
Configure Viewpoint for Nitro Web Services
Publish Nitro Events to Nitro Web Services

3.16.1 Open Necessary Ports

If your site is running firewall software on its hosts, you will need to configure the firewall to allow connections to the necessary ports.

In this section:

3.16.1.A Open the Tornado Web Port (9443) and the ZMQ Port (47100)
3.16.1.B Open the MongoDB Database Port (27017)

3.16.1.A Open the Tornado Web Port (9443) and the ZMQ Port (47100)

On the Nitro Web Services Host, do the following:

[root]# iptables-save > /tmp/iptables.mod
[root]# vi /tmp/iptables.mod

# Add the following lines immediately *before* the line matching
# "-A INPUT -j REJECT --reject-with icmp-host-prohibited"

-A INPUT -p tcp --dport 9443 -j ACCEPT
-A INPUT -p tcp --dport 47100 -j ACCEPT

[root]# iptables-restore < /tmp/iptables.mod
[root]# service iptables save

3.16.1.B Open the MongoDB Database Port (27017)

Nitro Web Services requires access to a MongoDB database. Depending on your system configuration, your MongoDB databases may not be installed on the same host as their corresponding component servers. For example, you may choose to install the Nitro Web Services MongoDB on the same host where you have installed other MongoDB databases.

Do the following, as needed:

If you have chosen to install the Nitro Web Services MongoDB database on the same host you installed other MongoDB databases confirm the firewall port (27017) is already opened on that host.

If you have chosen to install the Nitro Web Services MongoDB database on a different host from other MongoDB databases, you will need to open the Nitro Web Services MongoDB database port in the firewall for that host. To open the port in the firewall, do the following:

[root]# iptables-save > /tmp/iptables.mod
[root]# vi /tmp/iptables.mod

# Add the following lines immediately *before* the line matching
# "-A INPUT -j REJECT --reject-with icmp-host-prohibited"

-A INPUT -p tcp --dport 27017 -j ACCEPT

[root]# iptables-restore < /tmp/iptables.mod
[root]# service iptables save

3.16.2 Install MongoDB

If you have chosen to install the Nitro Web Services MongoDB database on a different host from other MongoDB databases, do the following on the host where the Nitro Web Services MongoDB database will reside (for example, on the Nitro Web Services Host):

Install MongoDB.

[root]# cat > /etc/yum.repos.d/mongodb.repo <<End-of-file
[mongodb]
name=MongoDB Repository
baseurl=http://downloads-distro.mongodb.org/repo/redhat/os/x86_64
gpgcheck=0
enabled=1
exclude=mongodb-org mongodb-org-server
End-of-file
[root]# yum install mongo-10gen-server

Start MongoDB
There may be a short delay (approximately 3 minutes) for Mongo to start the first time.
```
[root]# chkconfig mongod on
[root]# service mongod start
```
Prepare the MongoDB database by doing the following:
1. Add the required MongoDB users.
  The password used below (secret1) is an example. Choose your own password for this user.
```
[root]# mongo
> use admin;
> db.addUser("admin_user", "secret1");
> db.auth ("admin_user", "secret1");
> exit
```
  Because the admin_user has read and write rights to the admin database, it also has read and write rights to all other databases. See Control Access to MongoDB Instances with Authentication for more information.
2. Enable authentication in MongoDB.
```
[root]# vi /etc/mongod.conf
auth = true
[root]# service mongod restart
```

3.16.3 Install and Configure Nitro Web Services

You must complete the tasks earlier in this topic before installing Nitro Web Services.

On the host where Nitro Web Services will reside, do the following:

If you are installing Nitro Web Services on its own host or on a host that does not have another RPM installation, complete the steps to prepare the host. See 3.2 Preparing the Host – Typical Method or 3.4 Preparing the Host – Offline Method.

Install the Nitro Web Services RPM.

[root]# yum install -y nitro-web-services

Understand and edit the configuration files.

This includes clarifying what each configuration file is for and what to expect the first time the NWS service is started vs. each subsequent start.

MongoDB user, table, and index creation is performed at initial startup. Many of the options defined in the Nitro Web Service configuration files influence Mongo user/password and index creation.
Usernames and passwords are created only if they do not yet exist. Changing a password in the configuration file after initial startup will not update the password in Mongo.

The installation provides two configuration files
- /opt/nitro-web-services/etc/nitro.cfg
  This is the Nitro Web Services web application configuration file.
  Before initial startup, set "admin_username" and "admin_password" to the MongoDB admin username and password you used when setting up MongoDB. It is also recommended that you change all other default passwords before starting Nitro Web Services. If you do not change the passwords at this point, it will be more difficult to change them later.
  By default, NWS uses an auto-generated self-signed SSL certificate. However, you can use your own certfile, keyfile, and ca_certs files if you wish.
- /opt/nitro-web-services/etc/zmq_job_status_adapter.cfg
  This is the Nitro ZMQ Job Status Adapter configuration file.
  The Nitro ZMQ Job Status Adapter listens to job status updates on the ZMQ bus and publishes them to MongoDB using the Nitro Web Services REST API. The username and password must be set to a MongoDB user with write permissions. At minimum, set the password for nitro-writeonly-user to the password defined in /opt/nitro-web-services/etc/nitro.cfg and make sure the SSL options are set correctly based on SSL settings in /opt/nitro-web-services/etc/nitro.cfg.
If you did not need to install the Nitro Web Services MongoDB database earlier in this topic, verify that the 'mongodb_host' and 'mongodb_port' in /opt/nitro-web-services/etc/nitro.cfg are set correctly ('localhost' on port '27017' are the defaults).

Start the services and configure Nitro Web Services to start automatically at system boot.

[root]# chkconfig --add nitro-web-services
[root]# chkconfig --add nitro-zmq-job-status-adapter
[root]# service nitro-web-services start
[root]# service nitro-zmq-job-status-adapter start

3.16.4 Configure Viewpoint for Nitro Web Services

Do the following:

Using a web browser, navigate to your Viewpoint instance (http://<server>:8081) and then log in as the MWS administrative user (moab-admin, by default).

Click Configuration from the menu and then click Nitro Services from the left pane. The following is an example of the Nitro Services Configuration page.

Click to enlarge

Enter the configuration information. The following table describes the required information.

Field	Description
Nitro WS URL	Hostname (or IP address) and port number for the host on which you installed Nitro Web Services. For example, https://<hostname>:9443
Username	Name of the user. This typically nitro-readonly-user.
Password	The user's password.
Trust Self Signed	Indicates whether Nitro Web Services was set up using self-signed certificates.

Click TEST to confirm the settings are correct. This confirms whether Nitro Web Services is up and receiving connections.
Click SAVE to submit your settings.

(Recommended) Use curl to test Nitro Web Services connectivity.

[root]# curl --insecure --data '{"username": "nitro-admin", "password": "ChangeMe2!"}' \
 https://<hostname>:9443/auth

You should get something similar to the following in the response:

{
  "status": 200,
  "data": {
    "nitro-key": "3e0fb95e9a0e44ae91daef4deb500dcc67a3714880e851d781512a49",
    "user": {
      "username": "nitro-admin",
      "last_updated": "2016-02-26 23:34:55.604000",
      "name": "Nitro Admin",
      "created": "2016-02-26 23:34:55.604000",
      "auth": {
        "job": [
          "read",
          "write",
          "delete"
        ],
        "user": [
          "read",
          "write",
          "delete"
        ]
      }
    }
  }
}

3.16.5 Publish Nitro Events to Nitro Web Services

You need to configure the Nitro coordinators to send job status updates to the Nitro Web Services's ZMQ Job Status Adapter. The ZMQ Job Status Adapter is responsible for reading job status updates off of the ZMQ bus and persisting them to Mongo. Nitro Web Services can then be used to access Nitro job status.

Each Nitro job has a Nitro Coordinator. Nitro Coordinators can be configured to publish job status updates to ZMQ by setting the "nws-connector-address" configuration option in Nitro's nitro.cfg file. Each compute node allocated/scheduled to a Nitro Job can play the role of a Nitro coordinator. Therefore, you must update the "nws-connector-address" in each compute node's nitro.cfg file.

Configuring nws-connector-address is simplified if each node is sharing nitro's configuration over a shared filesystem. If you are not using a shared filesystem, update the nitro configuration on each compute node.

Do the following:

If you have not already done so, on the Nitro Web Services Host, locate the msg_port number in the /opt/nitro-web-services/etc/zmq_job_status_adapter.cfg file. This is the port number you need to specify for the nws-connector-address.

On each Nitro compute note (Torque MOM Host), specify the nws-connector-address in the /opt/nitro/etc/nitro.cfg file .

...
# Viewpoint connection allows Nitro to communicate job status information
# to viewpoint.  This option indicates name and port of the remote server
# in the form: <host>:<port>
nws-connector-address <nitro-web-services-hostname>:47100
...