Set up a user to connect to a Linux server with a private-public key pair

To secure a Linux server, disable password authentication on it. This way only those users can connect to it, who have access to an authorized private key. To enable users to connect to a Linux server with a private-public key pair Generate an RSA key pair In a Bash terminal on your workstation execute ssh-keygen Follow […]

Install a ZIP web application package with Octopus Deploy

Install the Octopus Tentacle on the application server. Automated Tentacle installation instructions are at (Note for our DevOps team: execute ~/Git/devops-scripts/OctopusDeploy/Tentacle_Installation/install_tentacle.ps1.) Make sure the box registered itself in the Octopus server. On the Deployment Targets tab of the Infrastructure menu enter the server name into the search box. The script already created the Environment and the Role and attached […]

Trigger an Octopus Deploy application package installation from TeamCity

Push the package to Octopus Deploy from TeamCity Create project level parameters In TeamCity create the parameters to centralize the configuration of reused values On the project level create a system parameter for the Octopus package name including the build number interpolation Push the artifact to Octopus Deploy Create a build configuration, and on the General Settings page […]

The user account does not have permission to run this task

When a Scheduled task is created by another user (or SYSTEM) most of the time only that user can manually trigger the task execution. When you try to execute the scheduled task from the user interface you can get the error message: The user account does not have permission to run this task This error […]

Error loading table definition of a PostgreSQL table

When a PostgreSQL table name contains uppercase letters there is no known way to get the table definition SQL script. When we right-click a table name in SQLPro for Postgres the has an uppercase letter and select Script as, CREATE to, New query window we get the error message /* * Error loading table definition. * ERROR: […]

Use two GitHub accounts on the same computer

Many developers have multiple GitHub accounts. One for personal projects, and another one for their work or business. There is a way to access multiple accounts simultaneously from the same computer. Only one account at a time can be configured using the HTTP connection, but we can configure the rest of the accounts using SSH. There are […]

Change the AWS account to launch instances with Chef Test Kitchen

The Chef SDK contains Test Kitchen, that can launch server instances to test your Chef cookbooks. Test Kitchen uses the “chef_zero” provisioner to use your workstation as the virtual Chef server. To switch Test Kitchen to launch instances in another AWS account In the .kitchen.yml file update the availability_zone subnet_id aws_ssh_key_id security_group_ids. Make sure the management […]

Copy files between Linux machines

The rsync command allows you to copy files using SSH connection, between your workstation and another Linux machine. You have to be logged into one of the machines, this command cannot copy files between two remote machines. To copy a file from your local machine to a remote server rsync -avz -e “ssh -i SSH_KEY_FILE -o […]

Using tmux terminal multiplexer

The tmux terminal multiplexer allows us to open multiple terminal windows in the same SSH session and continue the command execution even when we log out of the SSH session. This way we can execute long-running copy commands overnight without keeping the SSH session open. Install tmux On CentOS family Linux yum install tmux To start tmux […]

Add SSH key access to a GitHub repository

Generate an SSH key pair In a terminal execute ssh-keygen Generating public/private rsa key pair. Enter file in which to save the key : /Users/MY_USERNAME/Git/_Keys/MY_PROJECT/MY_PROJECT_rsa_ci Enter passphrase (empty for no passphrase): Enter same passphrase again: Leave the passphrase empty, many systems cannot work with password protected key pairs. This process will save the key-pair in […]