The PLC4X Project VM

As, especially for the raw socket functionality of PLC4X, our project had higher demands on the infrastructure as other projects. Apache Infra kindly provided us with a dedicated VM.

This is included as build agent into Apache’s Jenkins with the label plc4x1 and is marked for exclusive usage by our project.

The host name of this machine is: plc4x-vm.apache.org

On this machine we can even sudo to perform operations only available to root.

Project members can request access to the machine.

Requesting access

In order to be able to login, users need to add their SSH public key to their Apache ID first.

This is done under the following url: https://id.apache.org/

Here just add the content in the follwoing format to one of the SSH Key (authorized_keys line) fields:

ssh-rsa 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 my@email-address.com

(I just had to copy this line from my ~/.ssh/id_rsa.pub file)

Tip
Note, the Email Address in the end doesn’t seem to matter, I simply added it for the sake of completeness. So if this doesn’t match your Apache email, this is not a problem.

As soon as that’s done, access needs to be requested from Apache Infra.

This is done using the Infra Jira at: https://issues.apache.org/jira

Here make sure to select the Project Infrastructure (INFRA).

As soon as that’s handled by the Infra team, you should be ready to log-in on the machine.

Login to the machine

Using SSH we should now be able to login to the VM.

ssh apacheId@plc4x-vm2.apache.org

Be sure to use the username matching your Apache ID or the login will fail.

If all went well you should now be able to login to the machine using your apache user.

Doing things as root

Apache Infra is great at keeping things safe. Providing a sudo password directly would increase the danger of having this intercepted, therefore they are using a tool called opiepasswd.

Instead of now entering a password, a challenge is displayed:

myid@plc4x-vm2:~$ sudo apt-get update
otp-md5 496 pl8230
Password:

If you now enter your normal password, you’ll simply get permission denied errors.

In order to execute operations as root on the machine, you need to use an opie client.

otp-md5 496 pl8230

into OPIE client’s challenge field.

In the password field you provide your Apache LDAP password.

When hitting enter or clicking on Compute the tool should automatically generate a response.

Now all you need to do is copy & paste that as password into your SSH client session.

Tip
As with the latest version of Mac Catalina the existing clients no longer work and using a public web service is a really bad idea, Apache has a service to calculate: https://selfserve.apache.org/otp-md5.html

Required software

For being able to build the charts and graphics as part of the site generation, we need to add some additional packages:

sudo apt-get install python-seqdiag
sudo apt-get install python-nwdiag