Cloud-native API Administration with Red Hat 3scale API Management
In this course, the main computer system used for hands-on learning activities is workstation. The system called bastion must always be running. These two systems are in the lab.example.com DNS domain.
All student computer systems have a standard user account, student, which has the password student. The root password on all student systems is redhat.
Table 1. Classroom Machines
| Machine name | IP addresses | Role |
|---|---|---|
| workstation.lab.example.com | 172.25.250.9 | Graphical workstation used by students |
| bastion.lab.example.com | 172.25.250.254 | Router linking student's VMs to classroom servers |
| classroom.lab.example.com | 172.25.252.254 | Server hosting the classroom materials required by the course |
| utility.lab.example.com | 172.25.250.253 | Server providing supporting services required by the RHOCP cluster including DHCP and NFS and routing to the RHOCP servers. |
| master01.ocp4.example.com | 192.168.50.10 | An OpenShift control plane and compute node. |
| master02.ocp4.example.com | 192.168.50.11 | An OpenShift control plane and compute node. |
| master03.ocp4.example.com | 192.168.50.12 | An OpenShift control plane and compute node. |
The bastion system acts as a router between the network that connects the student machines and the classroom network. If bastion is down, other student machines may not function properly or may even hang during boot.
The utility system acts as a router between the network that connects the OpenShift cluster machines and the student network. If utility is down, the OpenShift cluster will not function properly or may even hang during boot.
Several systems in the classroom provide supporting services. Two servers, content.example.com and materials.example.com, are sources for software and lab materials used in hands-on activities. Information on how to use these servers is provided in the instructions for those activities.
Students use the workstation machine to access a dedicated OpenShift cluster, for which they have cluster administrator privileges.
You are assigned a remote computer in a Red Hat Online Learning classroom, which is accessed through a web application hosted at http:///. Students should log in to this site using their Red Hat Customer Portal user credentials.
The virtual machines in your classroom environment are controlled through a web page. The state of each virtual machine in the classroom is displayed on the page under the tab.
Table 2. Machine States
| Virtual Machine State | Description |
|---|---|
| active | The virtual machine is running and available (or, when booting, soon will be). |
| stopped | The virtual machine is completely shut down. |
| building | The initial creation of the virtual machine is being performed. |
Depending on the state of a machine, a selection of the following actions is available.
Table 3. Classroom/Machine Actions
| Button or Action | Description |
|---|---|
| Create the ROL classroom. Creates all of the virtual machines needed for the classroom and starts them. Can take several minutes to complete. | |
| Delete the ROL classroom. Destroys all virtual machines in the classroom. Caution: Any work generated on the disks is lost. | |
| Start all virtual machines in the classroom. | |
| Stop all virtual machines in the classroom. | |
| Open a new tab in the browser and connect to the console of the virtual machine. Students can log in directly to the virtual machine and run commands. In most cases, you should log in to the workstation virtual machine and use ssh to connect to the other virtual machines. | |
| → | Start (power on) the virtual machine. |
| → | Gracefully shut down the virtual machine, preserving the contents of its disk. |
| → | Forcefully shut down the virtual machine, preserving the contents of its disk. This is equivalent to removing the power from a physical machine. |
| → | Forcefully shut down the virtual machine and reset the disk to its initial state. Caution: Any work generated on the disk is lost. |
At the start of an exercise, if instructed to reset a single virtual machine node, click → for only the specific virtual machine.
At the start of an exercise, if instructed to reset all virtual machines, click →
If you want to return the classroom environment to its original state at the start of the course, you can click to remove the entire classroom environment. After the lab has been deleted, you can click to provision a new set of classroom systems.
Warning
The operation cannot be undone. Any work you have completed in the classroom environment up to that point will be lost.
The Red Hat Online Learning enrollment entitles students to a certain amount of computer time. To help conserve allotted computer time, the ROL classroom has an associated countdown timer, which shuts down the classroom environment when the timer expires.
To adjust the timer, click to add one hour to the timer. Note that there is a maximum time of twelve hours.
- Deleting 3scale resources does not work
Red Hat 3scale API Management is an eventually consistent distributed system. Deleting resources is a non-prioritized operation that takes time.
If you need to delete and recreate resources, for example by using the
lab finishand consequentlylab startcommands, then you might encounter failures, such as:Could not finish configuring product: Response(422 Unprocessable Entity): b'{"errors": {"System Name": ["has already been taken"]}}To work around the issue, wait after removing a resource. Removing a resource might take 10 minutes or longer.
You are assigned remote computers in a Red Hat Online Learning classroom. They are accessed through a web application hosted at . You should log in to this site using your Red Hat Customer Portal user credentials.
Controlling the Virtual Machines
The virtual machines in your classroom environment are controlled through a web page. The state of each virtual machine in the classroom is displayed on the page under the Online Lab tab.
Table 4. Machine States
| Virtual Machine State | Description |
|---|---|
| STARTING | The virtual machine is in the process of booting. |
| STARTED | The virtual machine is running and available (or, when booting, soon will be). |
| STOPPING | The virtual machine is in the process of shutting down. |
| STOPPED | The virtual machine is completely shut down. Upon starting, the virtual machine boots into the same state as when it was shut down (the disk will have been preserved). |
| PUBLISHING | The initial creation of the virtual machine is being performed. |
| WAITING_TO_START | The virtual machine is waiting for other virtual machines to start. |
Depending on the state of a machine, a selection of the following actions is available.
Table 5. Classroom/Machine Actions
| Button or Action | Description |
|---|---|
| Create the ROL classroom. Creates all of the virtual machines needed for the classroom and starts them. Can take several minutes to complete. | |
| Delete the ROL classroom. Destroys all virtual machines in the classroom. Caution: Any work generated on the disks is lost. | |
| Start all virtual machines in the classroom. | |
| Stop all virtual machines in the classroom. | |
Open a new tab in the browser and connect to the console of the virtual machine.
You can log in directly to the virtual machine and run commands.
In most cases, you should log in to the workstation virtual machine and use ssh to connect to the other virtual machines.
| |
| → | Start (power on) the virtual machine. |
| → | Gracefully shut down the virtual machine, preserving the contents of its disk. |
| → | Forcefully shut down the virtual machine, preserving the contents of its disk. This is equivalent to removing the power from a physical machine. |
| → | Forcefully shut down the virtual machine and reset the disk to its initial state. Caution: Any work generated on the disk is lost. |
At the start of an exercise, if instructed to reset a single virtual machine node, click → for only the specific virtual machine.
At the start of an exercise, if instructed to reset all virtual machines, click →
If you want to return the classroom environment to its original state at the start of the course, you can click to remove the entire classroom environment. After the lab has been deleted, you can click to provision a new set of classroom systems.
Warning
The operation cannot be undone. Any work you have completed in the classroom environment up to that point will be lost.
The Autostop Timer
The Red Hat Online Learning enrollment entitles you to a certain amount of computer time. To help conserve allotted computer time, the ROL classroom has an associated countdown timer, which shuts down the classroom environment when the timer expires.
To adjust the timer, click to display the New Autostop Time dialog box. Set the number of hours until the classroom should automatically stop. Note that there is a maximum time of ten hours. Click to apply this change to the timer settings.
