Fetch configlet python (#2180)

* convert fetch-configlet to Python

* allow retry on failure

* use more reliable methods for os/arch detection

Author: cmccandless

.travis.yml

@@ -16,6 +16,7 @@ matrix:
     - env: JOB=HOUSEKEEPING
       python: 3.7
       install:
+        - pip install requests
         - ./bin/fetch-configlet
         - git clone https://github.com/exercism/problem-specifications spec
         - pip install -r requirements-generator.txt

bin/fetch-configlet

@@ -1,33 +1,54 @@
-#!/bin/bash
-
-LATEST=https://github.com/exercism/configlet/releases/latest
-
-OS=$(
-case $(uname) in
-    (Darwin*)
-        echo "mac";;
-    (Linux*)
-        echo "linux";;
-    (Windows*)
-        echo "windows";;
-    (*)
-        echo "linux";;
-esac)
-
-ARCH=$(
-case $(uname -m) in
-    (*64*)
-        echo 64bit;;
-    (*686*)
-        echo 32bit;;
-    (*386*)
-        echo 32bit;;
-    (*)
-        echo 64bit;;
-esac)
-
-VERSION="$(curl --head --silent $LATEST | awk -v FS=/ '/Location:/{print $NF}' | tr -d '\r')"
-URL=https://github.com/exercism/configlet/releases/download/$VERSION/configlet-$OS-${ARCH}.tgz
-
-echo "Downloading configlet $VERSION for $OS-$ARCH..."
-curl -s --location $URL | tar xz -C bin/
+#!/usr/bin/env python3.7
+import io
+import tarfile
+import platform
+import requests
+import sys
+
+
+def download_and_extract(url):
+    resp = requests.get(url)
+    print('extracting...')
+    file = tarfile.open(fileobj=io.BytesIO(resp.content), mode='r:gz')
+    file.extractall(path='bin/')
+
+
+def get_os():
+    os_ = platform.platform()
+    if os_ == "Darwin":
+        return "mac"
+    elif os_ == "Windows":
+        return "windows"
+    return "linux"
+
+
+def get_arch():
+    return '64bit' if sys.maxsize > 2**32 else '32bit'
+
+
+def fetch_configlet():
+    latest = "https://api.github.com/repos/exercism/configlet/releases/latest"
+    resp = requests.get(latest)
+    data = resp.json()
+    version = data["tag_name"]
+    machine_info = f"{get_os()}-{get_arch()}"
+    name = f"configlet-{machine_info}.tgz"
+    for asset in data["assets"]:
+        if asset["name"] == name:
+            print(f"Downloading configlet {version} for {machine_info}")
+            download_and_extract(asset["browser_download_url"])
+            return 0
+    return 1
+
+
+def main():
+    max_retries = 5
+    for i in range(max_retries):
+        ret = fetch_configlet()
+        if ret == 0:
+            break
+    return ret
+
+
+if __name__ == "__main__":
+    sys.exit(main())