How Do You Troubleshoot The Terraform Error “Authentication using either SSH …must be enabled in Linux profile”?

0 Comments

Problem scenario
You try to run terraform apply to create an Azure VM but you receive a message like this:

Error: Error applying plan:

1 error(s) occurred:

* azurerm_virtual_machine.myterraformvm: 1 error(s) occurred:

* azurerm_virtual_machine.myterraformvm: compute.VirtualMachinesClient#CreateOrUpdate: Failure sending request: StatusCo” Message=”Authentication using either SSH or by user name and password must be enabled in Linux profile.” Target=”linux”

What should you do?

Solution
1.

…

Continue reading “How Do You Troubleshoot The Terraform Error “Authentication using either SSH …must be enabled in Linux profile”?”

How Do You Set up Nginx as an HTTP Load Balancer for Other Instances of Nginx Running in Docker?

0 Comments

Problem scenario
You have many Docker containers running Nginx.  You want to leverage these instances for users to go to one web site and then be automatically routed to different underlying Nginx instances in Docker containers.  How do you create a single website for web clients to go to with a reverse proxy balancing the load behind-the-scenes?

Solution
Overview
We accomplish an example with four Docker containers each using a free version of Nginx. 

…

Continue reading “How Do You Set up Nginx as an HTTP Load Balancer for Other Instances of Nginx Running in Docker?”

How Do You Set up Nginx as an HTTP Load Balancer So Client Requests (from Web Browsers) Go to Certain Nginx Servers More Frequently Than Others?

0 Comments

Problem scenario
You have certain Nginx servers with ample resources whereas others have minimal resources.  Based on geographic locations and data center bandwidth locations and costs, you want to assign fractions of the web traffic from client workstations (requests from web browsers) to different Nginx servers more than others.  You do not want round-robin, equal distribution of traffic.  You want customized HTTP load balancing in accord with unequal configurations.  How do you distribute this traffic proportionately according to your desired specifications?

…

Continue reading “How Do You Set up Nginx as an HTTP Load Balancer So Client Requests (from Web Browsers) Go to Certain Nginx Servers More Frequently Than Others?”

How Do You Troubleshoot The Linux Error “Failed to execute operation: Invalid argument”?

1 Comments

Problem scenario
You try to enable a service with this command: sudo systemctl enable foobar

But you get this error: “Failed to execute operation: Invalid argument”

What should you do?

Solution
1. Find the .service file for foobar (e.g., /etc/systemd/system/foobar.service).
2. Find the “Install” section. Is there an extra character? Make sure the line looks right. If you still have a problem,

…

Continue reading “How Do You Troubleshoot The Linux Error “Failed to execute operation: Invalid argument”?”

How Do You Delete a Kubernetes Cluster in AWS?

0 Comments

Problem scenario
You try to manually delete EC-2 instances (both worker nodes and the master node of Kubernetes), but this does not work. The EC-2 instances are re-created. How do you delete the cluster?

Solution
Prerequisite
Install and configure the AWS CLI; if you need assistance, see this posting.

Procedures
Run these three commands but substitute “contint.k8s.local” with the name of your cluster:

export KOPS_CLUSTER_NAME=contint.k8s.local
export KOPS_STATE_STORE=s3://$KOPS_CLUSTER_NAME-state
kops delete cluster –name contint.k8s.local –yes …

Continue reading “How Do You Delete a Kubernetes Cluster in AWS?”

How Do You Find The Web UI Credentials for Foreman after You Installed It?

0 Comments

Problem scenario
You want to log into the web UI of Foreman. What do you do?

Solution
1. Run this command: sudo find / -name foreman-installer -type f
2. Based on the results above, run this: sudo /path/to/foreman-installer –foreman-version # Replace “path/to” with the results of the first command (e.g., /usr/sbin/”).
3. The output from the above command should show you the credentials for the administrator user.

…

Continue reading “How Do You Find The Web UI Credentials for Foreman after You Installed It?”

How Do You Know What Version of Foreman Is Installed?

0 Comments

Problem scenario
You inherited a server with Foreman installed. What should you do to find out what version is installed?

Solution
1. Run this command: sudo find / -name foreman-installer -type f
2. Based on the results above, run this:
sudo /path/to/foreman-installer –foreman-version

# Replace “path/to” with the path results of the first command (e.g., /usr/sbin/”).

…

Continue reading “How Do You Know What Version of Foreman Is Installed?”