Test dependencies

hack/image-new-kube.py

@@ -0,0 +1,192 @@
+#!/usr/bin/env python3
+
+# Copyright 2019 The Kubernetes Authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import json
+import re
+import requests
+import sys
+import tarfile
+from io import BytesIO
+
+KUBE_SRC = "https://dl.k8s.io"
+
+KUBE_RESOLVED_SEM = "kubernetes_semver"
+KUBE_RESOLVED_SRC = "kubernetes_http_source"
+KUBE_RESOLVED_VER = "kubernetes_version"
+
+# KubeVersionResolver is used for resolving Kubernetes version strings to the
+# actual version and URL or package string that may be used to deploy
+# Kubernetes.
+
+
+class KubeVersionResolver(object):
+
+    # Resolve accepts a Kubernetes version string and returns a dictionary with
+    # information that can be used to deploy the provided version.
+    def Resolve(self, version):
+        if version == '':
+            raise Exception('version is required')
+
+        result = {
+            KUBE_RESOLVED_SEM: version,
+            KUBE_RESOLVED_SRC: 'pkg',
+            KUBE_RESOLVED_VER: version,
+        }
+
+        # When version is 'latest' then the returned dictionary points
+        # to the latest package for Kubernetes.
+        if version == 'latest':
+            return result
+        # Otherwise check to see if the provided version matches a
+        # managed package format. Technically the else clause could be
+        # descoped one level, but by placing the logic in the scope of
+        # the else clause, the scope of 'match' is isolated from the
+        # rest of this function.
+        else:
+            match = re.match(r'^(\d+\.\d+.\d+)\-\d+$', version)
+            if match:
+                version = match.groups(1)[0]
+                result[KUBE_RESOLVED_SEM] = f'v{version}'
+                return result
+
+        url = ''
+        if re.match(r'(?i)^https?:', version):
+            url = version
+        elif re.match(r'^v?\d+(?:\.\d+){0,3}(?:[.+-].+)?$', version):
+            if not version.startswith('v'):
+                version = f'v{version}'
+            url = f'{KUBE_SRC}/release/{version}'
+        elif re.match(r'^(ci|release)/.+$', version):
+            url = self.__resolve_build_url(version)
+        else:
+            raise Exception(f'Invalid Kubernetes version: {version}')
+        result[KUBE_RESOLVED_SRC] = url
+
+        version = self.__read_version_from_kube_tarball(url)
+        result[KUBE_RESOLVED_SEM] = version
+        result[KUBE_RESOLVED_VER] = version
+
+        return result
+
+    def __resolve_build_url(self, buildID):
+        url = f'{KUBE_SRC}/{buildID}'
+
+        # If the URL doesn't end with '.txt' then see if the URL is already valid.
+        if not url.endswith('.txt'):
+            # If there is a kubernetes tarball available at the root of the URL
+            # then it is already a valid URL.
+            try:
+                r = requests.head(url, allow_redirects=True)
+                if r.status_code >= 200 and r.status_code <= 299:
+                    return url
+            except:
+                pass
+            # The URL wasn't valid, so add '.txt' to the end and let's see if the
+            # URL points to a valid build.
+            url = f'{url}.txt'
+
+        # Do an HTTP GET on the txt file to get the actual Kubernetes version.
+        version = requests.get(url).text
+        version = version.strip()
+
+        if buildID.startswith('ci/'):
+            version = f'ci/{version}'
+        url = f'{KUBE_SRC}/{version}'
+
+        return url
+
+    def __read_version_from_kube_tarball(self, url):
+        url = f'{url}/kubernetes.tar.gz'
+        r = requests.get(url)
+        if not r.status_code == 200:
+            raise Exception(f'HTTP GET {url} failed: {r.status_code}')
+        b = BytesIO(r.content)
+        t = tarfile.open(fileobj=b, mode='r')
+        v = t.extractfile('kubernetes/version')
+        return v.read().strip().decode('utf-8')
+
+
+if __name__ == '__main__':
+    import argparse
+    import textwrap
+    parser = argparse.ArgumentParser(
+        formatter_class=argparse.RawTextHelpFormatter,
+        description='Generates new Kubernetes image config',
+        epilog=textwrap.dedent(r'''
+            THE VERSION STRING
+            ====================================================================
+            The version string not only determines what version of Kubernetes 
+            will be installed, but also *how* Kubernetes is installed.
+
+            PLACEHOLDERS
+            ====================================================================
+            The following placeholders are used in the examples below:
+
+            BASE_URI  https://dl.k8s.io
+            K8S_TGZ   kubernetes.tar.gz
+
+            PACKAGE MANAGER INSTALLATION
+            ====================================================================
+            If the version string matches the pattern "^\d+\.\d+.\d+\-\d+$",
+            ex. 1.14.0-0, then Kubernetes is installed using the system's
+            package manager, such as yum or apt.
+
+            MANUAL INSTALLATION
+            ====================================================================
+            If the string does not match the above pattern then the following
+            logic is used to resolve the string VALUE to a valid Kubernetes
+            version along with the URLs for the Kubernetes artifiacts required
+            for installation:
+
+              1. If the VALUE begins with "http:" or "https:" then the value is
+              treated as a URL and the Kubernetes version is obtained by reading
+              the "kuberentes/version" file from the URL "VALUE/K8S_TGZ".
+
+              2. If the VALUE matches a semantic version then the value is
+              treated as a release build and "BASE_URI/release/SEMVER"
+              is processed like the URL in step one.
+
+              3. If the VALUE begins with "ci/" then:
+              
+                a. If VALUE does not end with ".txt" then a HEAD request is used
+                to check the existence of "BASE_URI/VALUE/K8S_TGZ":
+                
+                  i. If the HEAD request is successful then the URL is processed
+                  like the one in step one.
+                  ii. If the HEAD request fails then ".txt" is added to the end
+                  of the URL and is processed by step 3b.
+
+                b. If VALUE *does* end with ".txt" then a GET request is used to
+                read "BASE_URI/VALUE" in order to get the dereferenced
+                version string. Then "BASE_URI/ci/DEREF" is processed
+                like the URL in step one.
+
+              4. If the VALUE begins with "release/" then the VALUE is processed
+              like step three, without the "ci/" prefix
+
+            The resolved URL is used to install Kuberentes from the set of
+            pre-built container images and binaries.
+    '''))
+    parser.add_argument('version',
+                        nargs=1,
+                        help='A Kubernetes version string')
+
+    args = parser.parse_args()
+    resolver = KubeVersionResolver()
+    result = resolver.Resolve(args.version[0])
+
+    data = json.dumps(result, indent=2)
+    print(data)