This Article provides a streamlined approach to automate Docker image tagging using versioning strategies.
It supports two main versioning approaches:
Semantic Versioning
Timestamp-based Versioning
Usage in Docker
After configuring Semantic/DateTimeStamp versioning, you can use it in docker like the following
docker build -t "imagename:$(pyv)" . #build docker image with semantic versioning
docker push "username/imagename:$(pyv)" #push docker image created with semantic versioning
docker build -t "imagename:$(dtsv)" . #build docker image with TimeStamp based versioning
Docker Image Reference Structure
🔹 REGISTRY_HOST:PORT (Optional): Specifies the hostname (and optional port) of the Docker registry.
🔹 NAMESPACE (Optional): Represents the user or organization account within the registry.
🔹 REPOSITORY (Required): The actual name of the image.
🔹 TAG (Optional but Important): Identifies a specific version or variant of the image.
myapp:1.0.0 (semantic version)
myapp:2025_10_14_1200 (timestamp-based tag)
myapp:latest (default if none specified)
Semantic Versioning
Semantic versioning is a widely adopted version scheme that encodes a version by a three-part version number (Major. Minor. Patch), an optional pre-release tag, and an optional build meta tag. In this scheme, risk and functionality are the measures of significance.
The core script pyv.py manages semantic versioning stored in a docker_version.json file. It allows incrementing major, minor, and patch versions, and displays the current version.
import json
import sys
import os
default_version={"major":1,"minor":0,"patch":0}
VERSION_FILE="docker_version.json"
def get_version():
if not os.path.exists(VERSION_FILE):
return default_version
with open(VERSION_FILE,"r") as f:
return json.load(f)
def save_version(version):
with open(VERSION_FILE,"w") as f:
json.dump(version,f,indent=2)
def format_version(version):
major=version["major"]
minor=version["minor"]
patch=version["patch"]
if patch==0:
if minor==0:
return f"{major}"
else:
return f"{major}.{minor}"
else:
return f"{major}.{minor}.{patch}"
def show_version():
v=get_version()
return format_version(v)
def update_version(version):
save_version(version)
return format_version(version)
def increment_major():
v=get_version()
v["major"]+=1
v["minor"]=0
v["patch"]=0
return update_version(v)
def increment_minor():
v=get_version()
v["minor"]+=1
v["patch"]=0
return update_version(v)
def increment_patch():
v=get_version()
v["patch"]+=1
return update_version(v)
if __name__ == '__main__':
if len(sys.argv)==1:
print(show_version())
sys.exit(0)
if len(sys.argv)>2:
print("Usage: pyv <major|minor|patch|show>")
sys.exit(1)
command=sys.argv[1]
if command=="major":
print(increment_major())
elif command=="minor":
print(increment_minor())
elif command=="patch":
print(increment_patch())
elif command=="show":
print(show_version())
else:
print("Invalid command. Use major|minor|patch|show as argument.")
sys.exit(1)
How it works
- If the version file does not exist, it initializes to version
1.0.0.
Supports commands:
show: Displays current version,
major: Increments major version,
minor: Increments minor version,
patch: Increments patch version
Usage
python pyv.py show
python pyv.py major
python pyv.py minor
python pyv.py patch
Global Command Setup
Linux Terminal
Create a pyv script (without.py extension)
#!/usr/bin/env python3
# Add the Python script code here
Make it executable and copy it to /usr/local/bin/
chmod +x pyv
sudo cp pyv /usr/local/bin/
Windows PowerShell
Create a batch file (pyv.bat)
@echo off
python "%~dp0pyv.py" %*
Set up PowerShell Profile
Test-Path $PROFILE
New-Item -ItemType File -Path $PROFILE -Force
notepad $PROFILE
Add alias to profile
Set-Alias pyv "C:\path\to\pyv.bat" #copy the absolute path of your pyv.bat file
Configure execution policy (if you are having restrected execution policy)
Get-ExecutionPolicy
Set-ExecutionPolicy -ExecutionPolicy RemoteSigned -Scope CurrentUser
Date Timestamps
This format automatically tags using timestamps in the pattern Year_Month_Day__Hour_Minute_Second to ensure unique and chronologically ordered names.
Linux
echo $SHELL #To know your shell
Set Date-Timestamps alias:
alias dtsv="date +'%Y_%m_%d__%H_%M_%S'"
Add Date-Timestamps alias to Shell configuration:
nano ~/.bashrc # or nano ~/.zshrc
After editing, source the profile:
source ~/.bashrc # or source ~/.zshrc
Windows PowerShell
Add the following function to your PowerShell profile to generate timestamp strings:
notepad $PROFILE
Add this function:
function dtsv { Get-Date -Format "yyyy_MM_dd__HH_mm_ss" }
Usage:
dtsv
This setup enables efficient Docker image tagging through semantic or timestamp-based versioning, with cross-platform support and easy integration into your build process.
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