In composer-cli, request all results

Add a limit argument to all potentially paginated results, equal to
whatever the composer backend is the total number of results. This still
has the potential to provide truncated data if the number of results
increases between the two HTTP requests.

Resolves: #404
(cherry picked from commit ee98d87cea)

src/composer/cli/blueprints.py

@@ -72,7 +72,7 @@ def blueprints_list(socket_path, api_version, args, show_json=False):
     blueprints list
     """
     api_route = client.api_url(api_version, "/blueprints/list")
-    result = client.get_url_json(socket_path, api_route)
+    result = client.get_url_json_unlimited(socket_path, api_route)
     (rc, exit_now) = handle_api_result(result, show_json)
     if exit_now:
         return rc
@@ -119,7 +119,7 @@ def blueprints_changes(socket_path, api_version, args, show_json=False):
     blueprints changes <blueprint,...>     Display the changes for each blueprint.
     """
     api_route = client.api_url(api_version, "/blueprints/changes/%s" % (",".join(argify(args))))
-    result = client.get_url_json(socket_path, api_route)
+    result = client.get_url_json_unlimited(socket_path, api_route)
     (rc, exit_now) = handle_api_result(result, show_json)
     if exit_now:
         return rc

src/composer/cli/modules.py

@@ -37,7 +37,7 @@ def modules_cmd(opts):
         return 1
 
     api_route = client.api_url(opts.api_version, "/modules/list")
-    result = client.get_url_json(opts.socket, api_route)
+    result = client.get_url_json_unlimited(opts.socket, api_route)
     (rc, exit_now) = handle_api_result(result, opts.json)
     if exit_now:
         return rc

src/composer/cli/projects.py

@@ -59,7 +59,7 @@ def projects_list(socket_path, api_version, args, show_json=False):
     projects list
     """
     api_route = client.api_url(api_version, "/projects/list")
-    result = client.get_url_json(socket_path, api_route)
+    result = client.get_url_json_unlimited(socket_path, api_route)
     (rc, exit_now) = handle_api_result(result, show_json)
     if exit_now:
         return rc

src/composer/http_client.py

@@ -20,6 +20,7 @@ log = logging.getLogger("composer-cli")
 import os
 import sys
 import json
+from urlparse import urlparse, urlunparse
 
 from composer.unix_socket import UnixHTTPConnectionPool
 
@@ -35,6 +36,29 @@ def api_url(api_version, url):
     """
     return os.path.normpath("/api/v%s/%s" % (api_version, url))
 
+def append_query(url, query):
+    """Add a query argument to a URL
+
+    The query should be of the form "param1=what&param2=ever", i.e., no
+    leading '?'. The new query data will be appended to any existing
+    query string.
+
+    :param url: The original URL
+    :type url: str
+    :param query: The query to append
+    :type query: str
+    :returns: The new URL with the query argument included
+    :rtype: str
+    """
+
+    url_parts = urlparse(url)
+    if url_parts.query:
+        new_query = url_parts.query + "&" + query
+    else:
+        new_query = query
+    return urlunparse([url_parts[0], url_parts[1], url_parts[2],
+                       url_parts[3], new_query, url_parts[5]])
+
 def get_url_raw(socket_path, url):
     """Return the raw results of a GET request
 
@@ -69,6 +93,31 @@ def get_url_json(socket_path, url):
     r = http.request("GET", url)
     return json.loads(r.data.decode('utf-8'))
 
+def get_url_json_unlimited(socket_path, url):
+    """Return the JSON results of a GET request
+
+    For URLs that use offset/limit arguments, this command will
+    fetch all results for the given request.
+
+    :param socket_path: Path to the Unix socket to use for API communication
+    :type socket_path: str
+    :param url: URL to request
+    :type url: str
+    :returns: The json response from the server
+    :rtype: dict
+    """
+    http = UnixHTTPConnectionPool(socket_path)
+
+    # Start with limit=0 to just get the number of objects
+    total_url = append_query(url, "limit=0")
+    r_total = http.request("GET", total_url)
+    json_total = json.loads(r_total.data.decode('utf-8'))
+
+    # Add the "total" returned by limit=0 as the new limit
+    unlimited_url = append_query(url, "limit=%d" % json_total["total"])
+    r_unlimited = http.request("GET", unlimited_url)
+    return json.loads(r_unlimited.data.decode('utf-8'))
+
 def delete_url_json(socket_path, url):
     """Send a DELETE request to the url and return JSON response