Merge ~ballot/charm-graylog/+git/charm-graylog:lp1896484 into charm-graylog:master

[Benjamin Allot]

Return as JSON the content only if not empty

Fixes: LP#1896484

[Paul Goins (vultaire)]

+1. Arguably it could be reworked to remove the addition of a return statement, but I don't think it's really that big a deal.

review: Approve

[Joe Guo (guoqiao)]

requests response object has builtin `.json()` method, maybe use that ?
ref: https://requests.readthedocs.io/en/latest/api/#requests.Response.json

Also, this function is returning boolean OR json, which is a bit weird.
Although that's out of the topic for this patch.

review: Needs Fixing

[Xav Paice (xavpaice)]

Agreed that it would potentially be preferable to use .json(), but the change is clear and readable as is. Looking at how this function is used, the patch as is will return None where there's no response, which is accounted for in the usage.

The structure of the function itself returning bool or a dict is something to review, but outside the scope of this change.

review: Approve

diff --git a/src/lib/charms/layer/graylog/api.py b/src/lib/charms/layer/graylog/api.py
index ca9cba1..98e52cf 100644
--- a/src/lib/charms/layer/graylog/api.py
+++ b/src/lib/charms/layer/graylog/api.py
@@ -34,7 +34,7 @@ class GraylogApi:
         self.req_timeout = 3
         self.req_retries = 4
 
-    def request(self, path, method="GET", data={}, params=None):
+    def request(self, path, method="GET", data={}, params=None):  # noqa: C901
         """Retrieve data by URL."""
         if path.startswith("/"):
             path = path[1:]
@@ -63,7 +63,8 @@ class GraylogApi:
                 if resp.ok:
                     if method == "DELETE":
                         return True
-                    return json.loads(resp.content.decode("utf-8"))
+                    if resp.content:
+                        return resp.json()
                 else:
                     msg = "API error code: {}".format(resp.status_code)
                     if charm: