[#199] Missing schema changes when user has no permissions on DB

This fixes many glitches with the schema deployment:
- silently ignoring real failure modes such as user not having
correct permissions on the DB
- a couple of broken upgrade steps
- adds --reset so schema can be fully redeployed

Netdisco/bin/netdisco-db-deploy

@@ -50,15 +50,20 @@ netdisco-db-deploy - Database deployment for Netdisco
 
 This script upgrades or initialises a Netdisco database schema.
 
+ ~netdisco/bin/netdisco-db-deploy [--reset]
+
+This script connects to the database and runs without user interaction. If
+there's no Nedisco schema, it is deployed. If there's an unversioned schema
+then versioning is added, and updates applied.  Otherwise only necessary
+updates are applied to an already versioned schema.
+
 Pre-existing requirements are that there be a database table created and a
 user with rights to create tables in that database. Both the table and user
 name must match those configured in your environment YAML file (default
 C<~/environments/deployment.yml>).
 
-Simply run this script, which connects to the database and runs without user
-interaction. If there's no Nedisco schema, it is deployed. If there's an
-unversioned schema then versioning is added, and updates applied.  Otherwise
-only necessary updates are applied to an already versioned schema.
+If you wish to force the redeployment of all database configuration, pass the
+C<--reset> argument on the command line.
 
 =head1 VERSIONS
 
@@ -74,7 +79,11 @@ Version 2 is the "classic" Netdisco database schema as of Netdisco 1.1
 
 =item *
 
-Version 5 (and onwards) adds patches for Netdisco 1.2
+Versions 5 to 16 add patches for Netdisco 1.2
+
+=item *
+
+Version 17 onwards deploys schema upgrades for Netdisco 2
 
 =back
 
@@ -82,6 +91,15 @@ Version 5 (and onwards) adds patches for Netdisco 1.2
 
 my $schema = schema('netdisco');
 
+if (scalar @ARGV and $ARGV[0] and $ARGV[0] eq '--reset') {
+    $schema->storage->dbh_do(
+      sub {
+        my ($storage, $dbh, @args) = @_;
+        $dbh->do('DROP TABLE dbix_class_schema_versions');
+      },
+    );
+}
+
 # installs the dbix_class_schema_versions table with version "1"
 # which corresponds to an empty schema
 if (not $schema->get_db_version) {
@@ -112,8 +130,9 @@ for (my $i = $db_version; $i < $target_version; $i++) {
         $schema->upgrade_single_step($i, $i + 1);
     }
     catch {
-        $schema->_set_db_version({version => $i + 1});
-    }
+        warn "Error: $_"
+          if $_ !~ m/(does not exist|already exists)/;
+    };
 }
 
 exit 0;