Initial Python version

.gitignore

@@ -15,3 +15,5 @@
 # Dependency directories (remove the comment below to include it)
 # vendor/
 
+__pycache__/
+venv/

Dockerfile

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+FROM python:3
+
+RUN mkdir -p /app
+WORKDIR /app
+
+COPY ./requirements.txt /app/
+RUN pip install -r ./requirements.txt
+COPY . /app
+
+CMD ["python", "./main.py"]

README.md

@@ -1,3 +1,8 @@
 # docker-check-version-updates
 
-Checks current running containers for newer tags according to semver
+Checks current running containers for newer tags according to semver
+
+Usage:
+
+    python -m venv venv
+    ./venv/bin/python main.py

main.py

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+"""
+Checks to see if newer tagged versions of running images exist
+
+When a newer tag based on semver is found, the tags will be printed and the script will exit with
+a non-zero code.
+"""
+from dataclasses import dataclass
+from typing import Generator
+from typing import List
+
+import docker  # type: ignore
+import requests
+
+
+class NotComparableException(ValueError):
+    pass
+
+
+@dataclass
+class ImageTag(object):
+    image_tag: str
+    image: str
+    full_tag: str
+    version: str
+    tag_desc: str
+    version_parts: List[int]
+
+    @classmethod
+    def from_str(cls, image_tag):
+        image, _, full_tag = image_tag.partition(":")
+        version, _, tag_desc = full_tag.partition("-")
+        # Remove leading v
+        if version[0].lower() == "v":
+            version = version[1:]
+        try:
+            version_parts = [int(p) for p in version.split(".")]
+        except ValueError:
+            version_parts = []
+        return ImageTag(
+            image_tag=image_tag,
+            image=image,
+            full_tag=full_tag,
+            version=version,
+            tag_desc=tag_desc,
+            version_parts=version_parts,
+        )
+
+    def is_same_image(self, other):
+        return self.image == other.image
+
+    def is_same_type(self, other):
+        return self.tag_desc == other.tag_desc
+
+    def is_same_grain(self, other):
+        return len(self.version_parts) == len(other.version_parts)
+
+    def is_comparable(self, other):
+        return all(
+            (
+                self.is_same_image(other),
+                self.is_same_type(other),
+                self.is_same_grain(other),
+            )
+        )
+
+    def __eq__(self, other):
+        if not self.is_comparable(other):
+            raise NotComparableException()
+
+        return self.version_parts == other.version_parts
+
+    def __lt__(self, other):
+        if not self.is_comparable(other):
+            raise NotComparableException()
+
+        for s, o in zip(self.version_parts, other.version_parts):
+            if s < o:
+                return True
+            elif s > o:
+                return False
+
+        return False
+
+    def is_newer_than(self, other):
+        return self.is_comparable(other) and self > other
+
+
+def get_all_tags(image_name: str) -> Generator[ImageTag, None, None]:
+    """Generates all tags for a given image"""
+    if "/" not in image_name:
+        image_name = f"library/{image_name}"
+    url = "https://registry.hub.docker.com/v2/repositories/{}/tags".format(
+        image_name,
+    )
+    page_count = 0
+    max_pages = 1000
+    while url and page_count <= max_pages:
+        data = requests.get(url).json()
+        for tag in data["results"]:
+            try:
+                yield ImageTag.from_str(f"{image_name}:{tag['name']}")
+            except ValueError:
+                pass
+
+        url = data["next"]
+        page_count += 1
+
+
+def generate_message(current: ImageTag, newer_tags: List[ImageTag]) -> str:
+    if not current.version_parts:
+        return f"[{current.image_tag}] No numeric version recognized"
+    if not newer_tags:
+        return f"[{current.image_tag}] No newer tags found for image tag"
+    else:
+        newer_tags = list(reversed(sorted(newer_tags)))
+        tags_list = ", ".join(tag.version for tag in newer_tags)
+        latest_tag = newer_tags[0].image_tag
+        return f"[{current.image_tag}] New versions found {tags_list}. Recommended update to {latest_tag}"
+
+
+def run() -> int:
+    client = docker.from_env()
+    running_images = {container.image.tags[0]
+              for container in client.containers.list()}
+
+    has_update = False
+    for image_name in running_images:
+        current = ImageTag.from_str(image_name)
+
+        newer_tags: List[ImageTag] = []
+        if current.version_parts:
+            newer_tags = [
+                tag for tag in get_all_tags(current.image) if tag.is_newer_than(current)
+            ]
+        has_update |= bool(newer_tags)
+        print(generate_message(current, newer_tags))
+
+    if has_update:
+        return 1
+    return 0
+
+
+if __name__ == "__main__":
+    exit(run())

requirements-dev.txt

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+pyls
+pyls-black
+ipython
+ipdb
+mypy

requirements.txt

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+requests
+docker