logForwarder - Online in the Cloud

PROGRAM:

NAME

logForwarder - Log item to manage ssh tunnels between log components and tools

NAME

logForwarder - Tools for creating and maintaining ssh tunnels between log components in
complex topologies

SYNOPSYS

logForwarder [options] ...

DESCRIPTION

logForwarder helps simplifying the maintenance of ssh tunnels between log components and
tools, thus improving log scalability and configuration in complex network topologies. The
components may be defined in a program to be monitored, they publish messages in the
LogCentral. The tools get the messages subscribing to the LogCentral.

Before starting a log forwarder, you must:

· launch omniNames on the local and remotes hosts.

· launch the remote peer only defining its name and network configuration.

· launch local peer and give him remote peer's name, ssh connection informations, remote
port to use and pass -C option to create the ssh tunnel.

[Remark: forwarders must be launched before the log tools/components]

OPTIONS

--name [name]
String identifying the forwarder

--peer-name [name]
String identifying its peer on the other network

--ssh-host [host]
Host hosting the ssh tunnel

--ssh-login [login]
Login used to establish the ssh connection (default: current user login).

--ssh-key [/path/to/ssh/key]
Path to the ssh key (the private one !) used to establish the ssh connection
(default: $HOME/.ssh/id_rsa).

--remote-port [port]
Port listening on the ssh host.

--remote-host [host]
Host to which the connection is made by the tunnel (corresponds to ssh options -L
and -R).

--nb-retry [nb]
Number of times that the local forwarder will try to bind itself to the remote
forwarder (default: 3).

--peer-ior [IOR]
Pass remote forwarder's IOR. By default, the local forwarder will retrive its peer
IOR.

--net-config [path/to/configuration/file]
Path to configuration file.

-C Create the tunnel from this forwarder.

CONFIGURATION FILE

You can pass a configuration file to dietForwarder instead of using command line options
through the --net-config option. Configuration file lists several rules describing
networks reachable using this forwarder.

There's two category of rules:

accept rules
describe which networks are accessible through the forwarder.

reject rules
describe which networks are not accessible through the forwarder.

A rule always starts by either accept: or reject: immediately followed by a regular
expression (Posix) describing host concerned by the rule. Rules are evaluated in the
following order: accept then reject. For instance:
accept:.* reject:localhost

This fragment means that the forwarder will accept connections to every hosts but
localhost.

EXAMPLE

Here's a simple configuration:

· We have two domains: net1 and net2, forwarders will be launched on hosts fwd.net1 and
fwd.net2.

· There's no link between hosts fwd.net1 and fwd.net2 but user may access fwd.net2 from
fwd.net1 using a ssh connection.

· We'll name fwd.net1 forwarder Fwd1 and fwd.net2 fowarder Fwd2.

· One tool lives in fwd.net2 while a component lives on the net1 domain.

Command line for launchind Fwd1

fwd.net1$ logForwarder --name Fwd1 --peer-name Fwd2 \
--ssh-host fwd.net2 --ssh-login dietUser \
--ssh-key id rsa net2 --remote-port 50000 \
--net-config net1.cfg -C

Command line to launch Fwd2

fwd.net2$ logForwarder --name Fwd2 --net-config net2.cfg

Configuration file for Fwd1

In this example, the forwarders Fwd1 accepts only the connections to fwd.net2.

accept:fwd.net2

Configuration file for Fwd2

In this example, the forwarders Fwd2 accepts all the connections except those which are
for the localhost.

accept:.*
reject:localhost

RATIONALE

The log service uses CORBA as its communication layer. While it's a flexible and robust
middleware, it remains hard deploying the log on heterogeneous networks that are not
reachable except through ssh tunnels. Log forwarders help administrator configuring their
grid without manually set-up ssh tunnels which arguably is neither simple nor scalable.
Log forwarders make it very easy configuring such topologies.

Use logForwarder online using onworks.net services