Knowledge Base for IT Professionals, Teachers and Astronauts
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, and the column name has an uppercase letter and select Script as, CREATE to, New query window we get the error message /* * Error loading …
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For some reason the .NETCore designers did not think, that developers want to follow best practices by separating the data layer from the presentation layer. The Entity framework out of the box only works if the database is accessed from the main application project. When we try to reverse engineer a PostgreSQL database from a …
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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 …
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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 (if different in each account) …
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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 …
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 …
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 …
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The CentOS images are not available on the AWS Quick Start tab. CentOS publishes official images on the AWS Marketplace, but you need to subscribe to the image to be able to launch it with an automation software, like Terraform. Find the latest available CentOS image in the AWS Marketplace Execute this command to display the …
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To generate graphs with Terraform Open a terminal window in the Terraform script directory Execute the command terraform graph | dot -Tsvg > graph.svg
In an enterprise environment, the company usually operates its own DNS servers. When a Linux instance launches in AWS, the DNS settings only contain the AWS DNS server. If the company DNS server settings are applied with Chef, during the first Chef Client run those settings do not take effect. When we reference an internal DNS …
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