scylla-manager: make --scylla-manager-package option more robust

* now it would first try to download from s3 via boto api (faster)
* local tar.gz file of manager can be used (no need to have it on s3/http)
* hash to identify the specific version now based on ETag and
  not on the url path itself.

Fixes: #463

ccmlib/scylla_repository.py

@@ -1,5 +1,3 @@
-
-
 import logging
 import random
 import time
@@ -16,17 +14,14 @@
 import glob
 import urllib
 
-import hashlib
 import requests
 import yaml
-
-
 import packaging.version
 
 from ccmlib.common import (
     ArgumentError, CCMError, get_default_path, rmdirs, validate_install_dir, get_scylla_version, aws_bucket_ls,
     DOWNLOAD_IN_PROGRESS_FILE, wait_for_parallel_download_finish, print_if_standalone)
-from ccmlib.utils.download import download_file, download_version_from_s3
+from ccmlib.utils.download import download_file, download_version_from_s3, get_url_hash
 from ccmlib.utils.version import parse_version
 
 GIT_REPO = "http://github.com/scylladb/scylla.git"
@@ -414,25 +409,30 @@ def download_packages(version_dir, packages, s3_url, scylla_product, version, ve
     return package_version, packages
 
 
-def setup_scylla_manager(scylla_manager_package=None):
+def setup_scylla_manager(scylla_manager_package=None, verbose=False):
 
     """
     download and cache scylla-manager RPMs,
     :return:
     """
 
     if scylla_manager_package and '--scylla-manager':
-        m = hashlib.md5()
-        m.update(scylla_manager_package.encode('utf-8'))
+        dir_hash = get_url_hash(scylla_manager_package)
 
-        # select a dir to change this version of scylla-manager based on the md5 of the path
-        manager_install_dir = directory_name(os.path.join('manager', m.hexdigest()))
+        # select a dir to change this version of scylla-manager based on the md5 of the path or the etag of the s3 object
+        manager_install_dir = directory_name(os.path.join('manager', dir_hash))
         if not os.path.exists(manager_install_dir):
             os.makedirs(manager_install_dir)
-            tar_data = requests.get(scylla_manager_package, stream=True)
             destination_file = os.path.join(manager_install_dir, "manager.tar.gz")
-            with open(destination_file, mode="wb") as f:
-                f.write(tar_data.raw.read())
+
+            if os.path.exists(scylla_manager_package) and scylla_manager_package.endswith('.tar.gz'):
+                destination_file = scylla_manager_package
+            elif is_valid(scylla_manager_package):
+                _, target = tempfile.mkstemp(suffix=".tar.gz", prefix="ccm-")
+                res = download_version_from_s3(url=scylla_manager_package, target_path=destination_file, verbose=verbose)
+                if not res:
+                    download_file(url=scylla_manager_package, target_path=destination_file, verbose=verbose)
+
             run(f"""
                 tar -xvf {destination_file} -C {manager_install_dir}
                 rm -f {destination_file}

ccmlib/utils/download.py

@@ -2,6 +2,7 @@
 import logging
 import shutil
 import urllib.parse
+import hashlib
 
 import tqdm
 import requests
@@ -158,3 +159,24 @@ def download_version_from_s3(url: str, target_path: str, verbose=False):
         transfer.download_file(bucket_name, download_path, target_path, callback=progress.update)
 
     return target_path
+
+
+def get_url_hash(url: str) -> str:
+    """
+    get hash (etag) or a blob in s3/http/local file/dir
+    """
+
+    if os.path.exists(url):  # if file/dir is local, hash based on the path
+        return hashlib.md5(url).hexdigest().encode()
+
+    # first try is on s3
+    parts = urllib.parse.urlparse(url)
+    _, bucket_name, download_path = parts.path.split('/', maxsplit=2)
+    s3_client = Session().client('s3', config=botocore.client.Config(signature_version=botocore.UNSIGNED))
+
+    try:
+        metadata = s3_client.head_object(Bucket=bucket_name, Key=download_path)
+        return metadata.get('ETag')[1:-1]
+    except botocore.client.ClientError as ex:
+        # fallback to http
+        return requests.head(url).headers.get('ETag')[1:-1]