Merge ~hloeung/content-cache-charm:master into content-cache-charm:master

[Haw Loeung]

Add map_sites_ports for persistent ports - LP:1865945

[🤖 Canonical IS Merge Bot (canonical-is-mergebot)]

This merge proposal is being monitored by mergebot. Change the status to Approved to merge.

[Joel Sing (jsing)]

LGTM, but see comments.

review: Approve (+1)

3b55472... by Haw Loeung on 2020-03-18

Fixed based on reviews

[Haw Loeung (hloeung)]

Rejected in favor of keeping the mappings in unitdata.kv(). See:

https://code.launchpad.net/~hloeung/content-cache-charm/+git/content-cache-charm/+merge/380871

Unmerged commits

3b55472... by Haw Loeung on 2020-03-18

Fixed based on reviews

ff8557e... by Haw Loeung on 2020-03-18

Add map_sites_ports for persistent ports - LP:1865945

map_sites_ports() to parse the on disk HAProxy config and build a list
of site to port-pair mappings.

diff --git a/lib/haproxy.py b/lib/haproxy.py
index e3a4d38..48cd495 100644
--- a/lib/haproxy.py
+++ b/lib/haproxy.py
@@ -282,3 +282,35 @@ backend backend-{name}
         with open(self.conf_file, 'w', encoding='utf-8') as f:
             f.write(content)
         return True
+
+    def map_sites_ports(self):
+        sites = {'cache': {}, 'backend': {}}
+        regex = {
+            'cache': re.compile(r"^\s+server server_\d 127.0.0.1:(\d+)"),
+            'backend': re.compile(r"^\s+bind 127.0.0.1:(\d+)"),
+            'backend-cache': re.compile(r"^backend backend-cached-(.*)\s*$"),
+        }
+        if not os.path.exists(self.conf_file):
+            return sites
+        with open(self.conf_file, 'r', encoding='utf-8') as f:
+            site = None
+            key = None
+            for line in f.readlines():
+                if line.startswith('listen'):
+                    site = line.split()[1]
+                    if site == 'stats':
+                        continue
+                    key = 'backend'
+                elif line.startswith('backend'):
+                    m = regex['backend-cache'].match(line)
+                    if m:
+                        site = m.group(1)
+                        key = 'cache'
+                if not site or not key:
+                    continue
+                m = regex[key].match(line)
+                if m:
+                    sites[key][site] = int(m.group(1))
+                    key = None
+
+        return sites
diff --git a/tests/unit/test_haproxy.py b/tests/unit/test_haproxy.py
index 1b2bb96..d596c4b 100644
--- a/tests/unit/test_haproxy.py
+++ b/tests/unit/test_haproxy.py
@@ -144,3 +144,37 @@ class TestLibHAProxy(unittest.TestCase):
             },
         }
         self.assertEqual(haproxy._merge_listen_stanzas(config), want)
+
+    def test_haproxy_map_sites_ports(self):
+        haproxy = HAProxy.HAProxyConf(self.tmpdir)
+
+        want = {'cache': {}, 'backend': {}}
+        self.assertEqual(haproxy.map_sites_ports(), want)
+
+        shutil.copyfile('tests/unit/files/content_cache_rendered_haproxy_test_output.txt', haproxy.conf_file)
+        want = {
+            'cache': {
+                'site1-local': 6080,
+                'site2-local': 6081,
+                'site3-local': 6082,
+                'site4-local': 6083,
+                'site5': 6084,
+                'site6-local': 6085,
+                'site7-local': 6086,
+                'site8-local': 6087,
+                'site9-local': 6088,
+            },
+            'backend': {
+                'site1-local': 8080,
+                'site2-local': 8081,
+                'site3-local': 8082,
+                'site5': 8083,
+                'site5-2': 8084,
+                'site6-local': 8085,
+                'site7-local': 8086,
+                'site8-local': 8087,
+                'site8-local-2': 8088,
+                'site9-local': 8089,
+            },
+        }
+        self.assertEqual(haproxy.map_sites_ports(), want)