Merge pull request #792 from Lucifergene/main

Auto Cleanup of Older Versions of Docker Images present in a System

Author: pawangeek

old_docker_images_auto_delete/README.md

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+# Auto Cleanup of Older Versions of Docker Images present in a System
+
+During Containerized Deployment of applications, often some VMs are particularly allotted for building the Docker Containers. Whenever a new code change takes place, automatically the CI/CD pipeline triggers the build of a new container containing the latest codes.
+
+Since the VMs have a fixed Disk Size, often storage issues arise, which lead to failure in the building of the containers leading to breakage in the CICD pipeline.
+
+Therefore it's necessary to remove older versions of the container images on a regular basis to avoid storage issues.
+
+**This script will preserve all the docker images containing the latest tag.
+For a particular repository, the tag with the highest number would be preserved.
+A provision is made to add exception images that would be never stopped.**
+
+## Setup instructions
+
+Make sure to have Docker Installed in your System.  
+Run the `main.py` file.  
+
+
+## Detailed explanation of script
+
+- All images with 'Alpine, Buster, Slim & Latest' tag would not be touched.  
+- For a particular repository, the tag with the highest number would be preserved.  
+- A provision is made to add exception images which would be never stopped.
+
+## Output
+
+```
+Deleting <Old Docker Image Name:Version>...
+```
+
+## Author(s)
+
+Avik Kundu
+
+## Disclaimer
+
+Be Careful Before Running this code.   
+Docker Image deletion cannot be reverted back.

old_docker_images_auto_delete/main.py

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+# Python Program to auto-delete old docker images
+"""
+    Rules:
+    1. All images with 'latest' tag would not be touched.
+    2. For a particular repository, the tag with
+        the highest number would be preserved.
+    3. A provision is made to add exception images
+         which would be never stopped.
+"""
+
+import subprocess as sp
+import re
+import operator
+import itertools
+
+
+class DeleteImage:
+    """
+    Deleting Old Docker Images
+    """
+    def __init__(self):
+        self.img_list = []
+        self.hash_list = []
+
+    def get_all(self):
+        """
+        Storing All the Docker Image Details Found on the System to a File
+        """
+        file = open("temp.txt", "r+", encoding='utf-8')
+        file.truncate(0)
+        sp.run("sudo docker image list --format '{{.Repository}}~{{.Tag}}' >> temp.txt",shell=True , capture_output=True, check=True) # noqa
+        file.close()
+
+    def is_excluded(self, tag):
+        """
+        Add other exceptions here
+        """
+        # Excluding all the images with Alpine, Buster, Slim & Latest Tags
+        reg = r"alpine|buster|slim|latest"
+        flag = re.search(reg, tag)
+        if flag is not None:
+            return 0
+        return 1
+
+    def load_all(self):
+        """
+        Loading data from the File to the Python program
+        """
+        file = open("temp.txt", "r", encoding='utf-8')
+
+        for line in file:
+            line = line.rstrip("\n")
+            image = line.split('~')
+            if self.is_excluded(image[1]):
+
+                regex = r"^(((\d+\.)?(\d+\.)?(\*|\d+)))(\-(dev|stage|prod))*$"
+                match = re.search(regex, image[1])
+
+                img_dict = {'Repository': image[0], 'Tag': match.group(2)}
+                self.img_list.append(img_dict)
+        file.close()
+
+    def man_data(self):
+        """
+        Manipulating Data to perform the reqd operation
+        """
+        key = operator.itemgetter('Repository')
+        b_key = [{'Repository': x, 'Tag': [d['Tag'] for d in y]}
+        for x, y in itertools.groupby(sorted(self.img_list, key=key), key=key)] # noqa
+
+        self.img_list.clear()
+        self.img_list = b_key.copy()
+
+    def sort_tag(self):
+        """
+        Sorting Tags according to the Version Numbers
+        """
+
+        for img in self.img_list:
+            temp = img['Tag'].copy()
+
+            for new, i in enumerate(img['Tag']):
+                img['Tag'][new] = int(i.replace('.', ''))
+
+            max_len = len(str(max(abs(x) for x in img['Tag'])))
+            template_string = '{:<0' + str(max_len) + '}'
+            final_list = []
+
+            for new, i in enumerate(img['Tag']):
+                final_list.append(template_string.format(i))
+
+            for i in range(0, len(img['Tag'])):
+                hash_map = {'TagsManipulated': final_list[i], 'TagsOriginal': temp[i]}  # noqa
+                self.hash_list.append(hash_map)
+
+            final_list.sort()
+
+            img['Tag'].clear()
+            img['Tag'].extend(final_list[:-1])
+
+        print(self.hash_list)
+        print(self.img_list)
+
+    def hash_function(self, tag):
+        """
+        Hash Function for Error Detection
+        """
+        for hash_map in self.hash_list:
+            if tag == hash_map['TagsManipulated']:
+                temp = hash_map['TagsOriginal']
+                break
+            else:
+                temp = 'Error in Manipulation'
+        return temp
+
+    def remove_image(self):
+        """
+        Running the Docker RMI Command to Delete the Older Versions
+        """
+        for img in self.img_list:
+            if img['Tag']:
+                for tag in img['Tag']:
+                    val = self.hash_function(tag)
+                    image_url = img['Repository'] + ":" + val
+                    print("Deleting Image : " + image_url)
+                    sp.run("sudo docker rmi " + image_url,shell=True,capture_output=True , check=True) # noqa
+
+
+# Main Function
+if __name__ == "__main__":
+
+    docker = DeleteImage()
+    docker.get_all()
+    docker.load_all()
+    docker.man_data()
+    docker.sort_tag()
+    docker.remove_image()