Installing cosmos-gui

Question

Can you help me with installing cosmos-gui? I think you are one of the developers behind cosmos? Am I right? We have already installed Cosmos, and now we want to install cosmos-gui. In the link below, I found the install guide: https://github.com/telefonicaid/fiware-cosmos/blob/develop/cosmos-gui/README.md#prerequisites

Under subchapter “Prerequisites” is written

A couple of sudoer users, one within the storage cluster and another one wihtin the computing clusters, are required. Through these users, the cosmos-gui will remotely run certain administration commands such as new users creation, HDFS userspaces provision, etc. The access through these sudoer users will be authenticated by means of private keys.

What is meant by the above? Must I create, a sudo user for the computing and storage cluster? And for that, do need to install a MySQL DB?

And under subchapter “Installing the GUI.”

Before continuing, remember to add the RSA key fingerprints of the Namenodes accessed by the GUI. These fingerprints are automatically added to /home/cosmos-gui/.ssh/known_hosts if you try an ssh access to the Namenodes for the first time.

I can't make any sense about the above. Can you give a step by step plan?

I hope you can help me.

JH

Answer 1

First of all, a reminder about the Cosmos architecture:

• There is a storage cluster based on HDFS.
• There is a computing cluster based on shared Hadoop or based on Sahara; that's up to the administrator.
• There is a services node for the storage cluster, a special node not storing data but exposing storage-related services such as HttpFS for data I/O. It is the entry point to the storage cluster.
• There is a services node for the computing cluster, a special node not involved in the computations but exposing computing-related services such as Hive or Oozie. It is the entry point to the computing cluster.
• There is another machine hosting the GUI, not belonging to any cluster.

Being said that, the paragraphs you mention try to explain the following:

• Since the GUI needs to perform certain sudo operations on the storage and computing clusters for user account creation purposes, then a sudoer user must be created in both the services nodes. These sudoer users will be used by the GUI in order to remotely perform the required operations on top of ssh.
• Regarding the RSA fingerprints, since the operations the GUI performs on the services nodes are executed in top of ssh, then the fingerprints the servers send back when you ssh them must be included in the .ssh/known_hosts file. You may do this manually, or simply ssh'ing the services nodes for the first time (you will be prompted to add the fingerprints to the file or not).
• MySQL appears in the requirements because that section is about all the requisites in general, and thus they are listed. Not necessarily there may be relation maong them. In this particular case, MySQL is needed in order to store the accounts information.

We are always improving the documentation, we'll try to explain this better for the next release.