chore: improve performance of python script for hash download (kubern…

…etes-sigs#10335)

The old version of the script downloaded all binaries and generated file checksums locally.
This was a slow process since all binaries of all architectures needed to be downloaded.
The new version simply downloads the .sha256 files containing the binary checksum in text
form which saves a lot of traffic and time.

scripts/download_hash.py

@@ -4,22 +4,21 @@
 # run this script to update roles/kubespray-defaults/defaults/main/download.yml
 # with new hashes.
 
-import hashlib
 import sys
 
 import requests
 from ruamel.yaml import YAML
 
-MAIN_YML = "../roles/kubespray-defaults/defaults/main/download.yml"
+CHECKSUMS_YML = "../roles/kubespray-defaults/defaults/main/checksums.yml"
 
-def open_main_yaml():
+def open_checksums_yaml():
     yaml = YAML()
     yaml.explicit_start = True
     yaml.preserve_quotes = True
     yaml.width = 4096
 
-    with open(MAIN_YML, "r") as main_yml:
-        data = yaml.load(main_yml)
+    with open(CHECKSUMS_YML, "r") as checksums_yml:
+        data = yaml.load(checksums_yml)
 
     return data, yaml
 
@@ -28,23 +27,33 @@ def download_hash(versions):
     architectures = ["arm", "arm64", "amd64", "ppc64le"]
     downloads = ["kubelet", "kubectl", "kubeadm"]
 
-    data, yaml = open_main_yaml()
+    data, yaml = open_checksums_yaml()
 
     for download in downloads:
         checksum_name = f"{download}_checksums"
         for arch in architectures:
             for version in versions:
                 if not version.startswith("v"):
                     version = f"v{version}"
-                url = f"https://dl.k8s.io/release/{version}/bin/linux/{arch}/{download}"
-                download_file = requests.get(url, allow_redirects=True)
-                download_file.raise_for_status()
-                sha256sum = hashlib.sha256(download_file.content).hexdigest()
+                url = f"https://dl.k8s.io/release/{version}/bin/linux/{arch}/{download}.sha256"
+                hash_file = requests.get(url, allow_redirects=True)
+                if hash_file.status_code == 404:
+                    print(f"Unable to find hash file for release {version} (arch: {arch})")
+                    continue
+                if hash_file.status_code != 200:
+                    raise Exception(f"Received a non-200 HTTP response code: {hash_file.status_code} (arch: {arch}, version: {version})")
+                sha256sum = hash_file.content.decode().strip()
+                if len(sha256sum) != 64:
+                    raise Exception(f"Checksum has an unexpected length: {len(sha256sum)} (arch: {arch}, version: {version})")
+                if checksum_name not in data:
+                    data[checksum_name] = {}
+                if arch not in data[checksum_name]:
+                    data[checksum_name][arch] = {}
                 data[checksum_name][arch][version] = sha256sum
 
-    with open(MAIN_YML, "w") as main_yml:
-        yaml.dump(data, main_yml)
-        print(f"\n\nUpdated {MAIN_YML}\n")
+    with open(CHECKSUMS_YML, "w") as checksums_yml:
+        yaml.dump(data, checksums_yml)
+        print(f"\n\nUpdated {CHECKSUMS_YML}\n")
 
 
 def usage():