Merge pull request #214 from slinderud/master

Templating: improved templating.py, added readme with examples, and a test template that uses the API

1 files changed, 26 insertions, 11 deletions

diff --git a/templating/templating.py b/templating/templating.py
index 87853b6..1eff4a3 100755
--- a/templating/templating.py
+++ b/templating/templating.py
@@ -8,20 +8,26 @@ import netaddr
 import requests
 
 from flask import Flask, request
-from jinja2 import Environment, FileSystemLoader, TemplateNotFound
+from jinja2 import Environment, FileSystemLoader, TemplateNotFound, TemplateError
 
-endpoints = "read/networks read/oplog read/snmp read/switches-management public/distro-tree public/config public/dhcp public/dhcp-summary public/ping public/switches public/switch-state".split()
+endpoints = ["read/networks", "read/oplog", "read/snmp", "read/switches-management", "public/distro-tree",
+             "public/config", "public/dhcp", "public/dhcp-summary", "public/ping", "public/switches",
+             "public/switch-state"]
 
 objects = {}
 
 
-def getEndpoint(endpoint):
-    r = requests.get("http://localhost:80/api/{}".format(endpoint))
-    if r.status_code != 200:
-        raise Exception("Bad status code for endpoint {}: {}".format(endpoint, r.status_code))
-    return r.json()
 
 
+def getEndpoint(endpoint: str) -> dict:
+    """
+    Fetches an endpoint and returns the data as a dict.
+    """
+    uri = f"{args.server}/api/{endpoint}"
+    r = requests.get(uri, timeout=args.timeout)
+    r.raise_for_status()
+    return r.json()
+
 def updateData():
     for a in endpoints:
         objects[a] = getEndpoint(a)
@@ -52,14 +58,20 @@ def add_header(response):
 
 @app.route("/<path>", methods=["GET"])
 def root_get(path):
-    updateData()
     try:
+        updateData()
         template = env.get_template(path)
         body = template.render(objects=objects, options=request.args)
+    except (requests.exceptions.ConnectTimeout, requests.exceptions.ConnectionError) as error:
+        return f'Timeout or connection error from gondul: {err}', 500
     except TemplateNotFound:
-        return 'Template "{}" not found\n'.format(path), 404
+        return f'Template "{path}" not found\n', 404
+    except TemplateError as err:
+        return f'Templating of "{path}" failed to render. Most likely due to an error in the template. Error transcript:\n\n{err}\n----\n\n{traceback.format_exc()}\n', 400
+    except requests.exceptions.HTTPError as err:
+        return f'HTTP error from gondul: {err}', 500
     except Exception as err:
-        return 'Templating of "{}" failed to render. Most likely due to an error in the template. Error transcript:\n\n{}\n----\n\n{}\n'.format(path, err, traceback.format_exc()), 400
+        return f'Uncaught error: {err}', 500
     return body, 200
 
 
@@ -71,7 +83,7 @@ def root_post(path):
         template = env.from_string(content.decode("utf-8"))
         body = template.render(objects=objects, options=request.args)
     except Exception as err:
-        return 'Templating of "{}" failed to render. Most likely due to an error in the template. Error transcript:\n\n{}\n----\n\n{}\n'.format(path, err, traceback.format_exc()), 400
+        return 'Templating of "{path}" failed to render. Most likely due to an error in the template. Error transcript:\n\n{err}\n----\n\n{traceback.format_exc()}\n', 400
     return body, 200
 
 
@@ -80,11 +92,14 @@ parser.add_argument("-t", "--templates", type=str, nargs="+", help="location of
 parser.add_argument("-h", "--host", type=str, default="127.0.0.1", help="host address")
 parser.add_argument("-p", "--port", type=int, default=8080, help="host port")
 parser.add_argument("-d", "--debug", action="store_true", help="enable debug mode")
+parser.add_argument("-s", "--server", type=str, default="http://localhost:80", help="gondul server address")
+parser.add_argument("-x", "--timeout", type=int, default=2, help="gondul server timeout")
 
 args = parser.parse_args()
 env.loader.searchpath = args.templates
 
 if not sys.argv[1:]:
     parser.print_help()
+    sys.exit(1)
 
 app.run(host=args.host, port=args.port, debug=args.debug)