DEV Community: Aditya Shrivastav

Running PostgreSQL and pgAdmin 4 in Docker: A Complete Guide

Aditya Shrivastav — Sat, 29 Jun 2024 04:51:48 +0000

Deploying databases in a containerized environment can simplify development and management processes. Docker is a powerful tool that allows you to package applications and their dependencies into isolated containers. In this blog post, we'll walk through the steps to set up a PostgreSQL database along with PgAdmin 4 using Docker.

Prerequisites

Before we begin, make sure you have the following installed on your system:

Docker Desktop
Docker Compose (Optional*)

Setup

Step 1: Run the PostgreSQL Docker Container

docker run --env POSTGRES_PASSWORD=password123 --env POSTGRES_DB=postgres --env POSTGRES_USER=postgres -v postgres-volume:/var/lib/postgresql/data -p 5432:5432 --name postgres -d postgres

The command above will create a new PostgreSQL container named postgres using image postgres with the following configurations:

POSTGRES_PASSWORD: The password for the postgres user.
POSTGRES_DB: The name of the default database to be created.
POSTGRES_USER: The name of the default user to be created.
Create a volume named postgres-volume to persist the database data and mount it to the /var/lib/postgresql/data directory inside the container.
Bind port 5432 of the host machine to port 5432 of the container.
-d flag to run the container in detached mode. If you want to run the container in the foreground, you can omit this flag.

Docker Compose

The same command can be converted into a docker-compose.yml file as shown below:

version: '3'
services:
  postgres:
    image: postgres
    container_name: postgres
    environment:
      - POSTGRES_DB=postgres
      - POSTGRES_USER=postgres
      - POSTGRES_PASSWORD=password123
    ports:
      - "5432:5432"
    volumes:
      - postgres-volume:/var/lib/postgresql/data
volumes:
  postgres-volume:
    driver: local

You can start the PostgreSQL container by running the following command:

docker compose up -d
#or
docker-compose up -d

Docker compose will save you from typing long commands and make it easier to manage multiple containers. You can also define multiple services in the same docker-compose.yml file. It is recommended to use this approach for managing containers in a production environment.

Step 2: Installing PgAdmin 4 Docker Extension

You don't need to install PgAdmin 4 separately. You can use the official Docker image provided by the PgAdmin team. Or better you can use the PgAdmin4 Docker extension. Using the extension is more convenient as it allows you to manage your PostgreSQL database directly from the Docker Desktop UI. Internally it also uses the official PgAdmin 4 Docker image.

Install the extension. It will automatically download the official PgAdmin 4 Docker image and run it in a container named pgadmin4\ when you click on the PgAdmin 4 icon in the Docker Desktop UI.

Click on the PgAdmin 4 icon in the Docker Desktop UI to open the PgAdmin 4 web interface.

After opening the PgAdmin 4 will ask you to set a master password for the PgAdmin 4 web interface. This is because you can store your database credentials in the PgAdmin 4 web interface. So make sure to set a strong password.

Click on the Add New Server button to add a new server connection.

This will open a new window where you can configure the connection details for your PostgreSQL server.

Enter any name for the connection and switch to the Connection tab.

Enter the following details:

Host name/address: host.docker.internal. This is the hostname that Docker Desktop uses to connect to the host machine. There are some blogs that suggest using localhost or the IP address of the postgres container. But using host.docker.internal is the most reliable way to connect to the host machine from a Docker container.
Port: 5432
Maintenance database: postgres. It is the name of the default database that we created in the PostgreSQL container from environment variable POSTGRES_DB.
Username: postgres. It is the name of the default user that we created in the PostgreSQL container from environment variable POSTGRES_USER.
Password: password123. The password we set for the postgres user in the PostgreSQL container.
Optionally, you can save the password in the PgAdmin 4 web interface by checking the Save password? checkbox.

Hit the Save button to save the connection details.

Now you can see the connection in the left sidebar under the Servers section.

Conclusion

In this blog post, we learned how to set up a PostgreSQL database along with PgAdmin 4 using Docker. Docker makes it easy to create isolated environments for your applications and manage dependencies effectively. By following the steps outlined in this post, you can quickly get started with PostgreSQL and PgAdmin 4 in a containerized environment.

If you have any questions or feedback, feel free to leave a comment below. Happy coding!

How to Set Permanent and Temporary Aliases in PowerShell and Bash: A Step-by-Step Guide

Aditya Shrivastav — Wed, 19 Jun 2024 10:33:56 +0000

Aliases are shortcuts that allow you to create custom commands to save time and improve efficiency when working in the terminal. Both PowerShell and Bash support aliasing, but the methods for setting permanent and temporary aliases differ between these shells. In this guide, we'll walk you through the steps to create and manage aliases in both PowerShell and Bash.

Setting Aliases in PowerShell

Temporary Aliases

Temporary aliases in PowerShell exist only for the duration of your current session. Once you close the terminal, these aliases will be lost.

Creating a Temporary Alias:

Open PowerShell.
Use the Set-Alias cmdlet to create your alias.
```
Set-Alias ll Get-ChildItem
```
In this example, ll is an alias for the Get-ChildItem cmdlet, which is similar to ls in Unix-based systems.

Viewing Aliases:

To see a list of all aliases, use the Get-Alias cmdlet:

Get-Alias

Permanent Aliases

To make an alias permanent, you need to add it to your PowerShell profile script. This script runs every time a new PowerShell session starts.

Creating a Permanent Alias:

Open PowerShell.
Open your PowerShell profile in a text editor. You can do this by running:
```
notepad $PROFILE
```
If the profile does not exist, this command will create it. You can also use your favorite text editor like VS Code or Sublime text, here I have used notepad for simplicity.
Write the same command in the profile script:
```
Set-Alias ll Get-ChildItem
```
Save and close the text editor.
To apply the changes immediately without restarting PowerShell, run:
```
. $PROFILE
```

Setting Aliases in Bash

Temporary Aliases

Temporary aliases in Bash also exist only for the current session. They will be lost once you close the terminal.

Creating a Temporary Alias:

Open a terminal.
Use the alias command to create your alias.
```
alias ll='ls -la'
```
In this example, ll is an alias for the ls -la command.

Viewing Aliases:

To see a list of all aliases, use the alias command without any arguments:

alias

Permanent Aliases

To make an alias permanent, you need to add it to your shell's configuration file, such as .bashrc or .bash_profile.

Creating a Permanent Alias:

Open a terminal.
Open your .bashrc file in a text editor. You can do this with nano or vi
```
nano ~/.bashrc
```
Add your alias command in the .bashrc file:
```
alias ll='ls -la'
```
Save and close the text editor.
To apply the changes immediately without restarting the terminal, run:
```
source ~/.bashrc
```

Conclusion

Setting aliases in PowerShell and Bash can greatly enhance your productivity by reducing the amount of typing required for frequently used commands. Whether you need a temporary alias for a quick task or a permanent one for everyday use, the steps outlined above will help you configure your terminal to suit your workflow. Experiment with different aliases to find the ones that best fit your needs. Happy aliasing!

How to create a Virtual Environment in Python in 1 Minute?

Aditya Shrivastav — Mon, 17 Jun 2024 09:58:21 +0000

A virtual environment in Python is a self-contained directory that contains a specific Python interpreter and a set of installed packages. It allows you to isolate your Python project's dependencies from the system-wide Python installation and other projects.

By creating a virtual environment, you can have different versions of Python and different sets of packages for each project, without worrying about conflicts or dependencies between them. This is particularly useful when working on multiple projects that require different versions of packages or when collaborating with others who may have different setups.

When you activate a virtual environment, it modifies the system's PATH environment variable to prioritize the Python interpreter and packages within the virtual environment. This ensures that when you run Python commands or install packages, they are specific to that environment.

How to create a virtual environment in Python?

There are several ways to create a virtual environment in Python, we will learn the most common methods which are using venv module using CLI and extention in VSCode.

1. Using `venv` module in CLI

The venv module is the built-in tool for creating virtual environments in Python. Here's how you can create a virtual environment using venv in the command line:

Open your terminal or command prompt.
Navigate to the directory where you want to create the virtual environment.
Run the following command to create a virtual environment named myenv:

Windows:
```
python -m venv myenv
```
macOS/Linux:
```
python3 -m venv myenv
```
To activate the virtual environment, run the following command:

Windows:
```
myenv\Scripts\activate
```
macOS/Linux:
```
source myenv/bin/activate
```
This will run a script that modifies your shell's PATH to prioritize the Python interpreter and packages within the virtual environment.
You should see the name of the virtual environment (myenv) in your terminal prompt, indicating that the virtual environment is active.

Sometimes in VS Code you may not see the (myenv) in the terminal prompt, butyou can verify the activation by running where.exe python or which python3 command. It should point to the Python interpreter within the virtual environment.
You can now install packages using pip or run Python scripts within this virtual environment.
To deactivate the virtual environment, simply run the deactivate command in the terminal which will be found in the env > Scripts folder in the project.
To delete the virtual environment, you can simply delete the directory containing it.
That's it! You have successfully created and activated a virtual environment in Python using venv.

2. Using the Python extension in VSCode

Open your Python project in Visual Studio Code (VSCode).
Click on the Python interpreter in the bottom left corner of the VSCode window.
Click on Create Virtual Environment.
Choose venv as the virtual environment type.
Select the base interpreter (Python version) to use for the virtual environment.
The virtual environment will be created in a .venv directory within your project.
Now if you open a new terminal in VSCode, it should automatically activate the virtual environment. > Sometimes in VS Code you may not see the (myenv) in the terminal prompt, butyou can verify the activation by running where.exe python or which python3 command. It should point to the Python interpreter within the virtual environment.
If the above did't work for you, use Python extension in VSCode to select the interpreter from the virtual environment. https://marketplace.visualstudio.com/items?itemName=donjayamanne.python-environment-manager

Conclusion

Creating a virtual environment in Python is a simple yet powerful way to manage your project's dependencies and ensure that they are isolated from other projects and the system-wide Python installation. By following the steps outlined above, you can quickly set up a virtual environment for your project and start developing with confidence.

I hope this article has been helpful in understanding how to create a virtual environment in Python. If you have any questions or feedback, please feel free to reach out. Happy coding!

Do share this article with your friends and colleagues who might find it useful. Thank you for reading!

DEV Community: Aditya Shrivastav

Running PostgreSQL and pgAdmin 4 in Docker: A Complete Guide

Prerequisites

Setup

Step 1: Run the PostgreSQL Docker Container

Docker Compose

Step 2: Installing PgAdmin 4 Docker Extension

Conclusion

How to Set Permanent and Temporary Aliases in PowerShell and Bash: A Step-by-Step Guide

Setting Aliases in PowerShell

Temporary Aliases

Permanent Aliases

Setting Aliases in Bash

Temporary Aliases

Permanent Aliases

Conclusion

How to create a Virtual Environment in Python in 1 Minute?

How to create a virtual environment in Python?

1. Using venv module in CLI

2. Using the Python extension in VSCode

Conclusion

1. Using `venv` module in CLI