Combine artifact URLs with log_url if relative

The plan for the idea of a "promote" pipeline is to fetch
previously uploaded artifacts from the build log server
and move them to the final publication location.  However,
jobs which store data (such as documentation builds,
tarballs, or container images) on the log server should not
need to know the configuration of the log server in order
to return the artifact URL to zuul.  To support this, if
the job returns a relative URL for an artifact, assume it
is relative to the log URL for the build and combine the
two when storing the artifact info.

Change-Id: I4bce2401c9e59fd469e3b3da2973514c07faecf2

zuul/driver/sql/sqlreporter.py

@@ -16,6 +16,7 @@ import datetime
 import logging
 import time
 import voluptuous as v
+import urllib.parse
 
 from zuul.reporter import BaseReporter
 
@@ -32,7 +33,9 @@ class SQLReporter(BaseReporter):
     }
     zuul_data = {
         'zuul': {
-            'artifacts': [artifact]
+            'log_url': str,
+            'artifacts': [artifact],
+            v.Extra: object,
         }
     }
     artifact_schema = v.Schema(zuul_data)
@@ -103,11 +106,29 @@ class SQLReporter(BaseReporter):
                 if self.validateArtifactSchema(build.result_data):
                     artifacts = build.result_data.get('zuul', {}).get(
                         'artifacts', [])
+                    default_url = build.result_data.get('zuul', {}).get(
+                        'log_url')
+                    if default_url:
+                        if default_url[-1] != '/':
+                            default_url += '/'
                     for artifact in artifacts:
+                        url = artifact['url']
+                        if default_url:
+                            # If the artifact url is relative, it will
+                            # be combined with the log_url; if it is
+                            # absolute, it will replace it.
+                            try:
+                                url = urllib.parse.urljoin(default_url, url)
+                            except Exception:
+                                self.log.debug("Error parsing URL:",
+                                               exc_info=1)
                         db_build.createArtifact(
                             name=artifact['name'],
-                            url=artifact['url'],
+                            url=url,
                         )
+                else:
+                    self.log.debug("Result data did not pass artifact schema "
+                                   "validation: %s", build.result_data)
 
 
 def getSchema():