fix(cli): report format unfound error w/ REST API

Report error instead of crashing in fatbuildrctl when unable to find
format corresponding to a given distribution with fatbuildrweb REST API.

fix #172

CHANGELOG.md

@@ -224,6 +224,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   definition file (#171).
 - Handle JSON decode error in `fatbuildrctl` in case of unexpected failure in
   `fatbuildrweb` (#146).
+- Report error instead of crashing in `fatbuildrctl` when unable to find format
+  corresponding to a given distribution with fatbuildrweb REST API (#172).
 - docs:
   - Add missing path parameter in REST API to retrieve artifact information.
   - Add missing optional `architectures` parameter in instances pipelines

fatbuildr/protocols/http/client.py

@@ -109,6 +109,11 @@ def pipelines_distribution_format(self, distribution):
         url = f"{self.uri}/pipelines/formats.json?distribution={distribution}"
         response = self._auth_request(requests.get, url)
         formats = response.json()
+        if len(formats) == 0:
+            raise FatbuildrServerError(
+                "Unable to find format corresponding to distribution "
+                f"{distribution}"
+            )
         return list(formats.keys())[0]
 
     @check_http_errors