Add bionic support

This change is mostly a port of the change authored by mthaddon
to add bionic support to the charm.

As noted in the readme postgres 10 is currently not supported so the
corresponding functional test uses a xenial postgresql node.

Change-Id: I3f11f024ced8aa5ae58135d5e5e23ed94d4c31f9

src/README.md

@@ -11,7 +11,9 @@ SSH credentials, and more.
 ## About the Charm
 
 This charm installs Vault from the Ubuntu Snap Store and
-supports the PostgreSQL storage backend only.
+supports the PostgreSQL and MySQL storage backends. Note that Vault itself
+does not support PostgreSQL 10, so neither does this charm. If you're
+deploying on bionic, you'll need to deploy a 9.x version of PostgreSQL.
 
 After deploying and relating the charm to postgresql, install
 the vault snap locally and use "vault init" to create the

src/metadata.yaml

@@ -12,8 +12,8 @@ description: |
   credentials, SQL/NoSQL databases, X.509 certificates,
   SSH credentials, and more.
 series:
-  - bionic
   - xenial
+  - bionic
 tags:
   - security
 requires:

src/reactive/vault.py

@@ -141,7 +141,7 @@ def mysql_setup(database):
 @when_not('vault.schema.created')
 def create_vault_table(pgsql):
     status_set('maintenance', 'connecting to database')
-    conn = psycopg2.connect(pgsql.master)
+    conn = psycopg2.connect(str(pgsql.master))
     cur = conn.cursor()
     status_set('maintenance', 'creating vault table')
     cur.execute(VAULT_TABLE_DDL)

src/tests/bundles/bionic-postgres.yaml

@@ -0,0 +1,13 @@
+series: bionic
+services:
+  vault:
+    num_units: 1
+    series: bionic
+    charm: ../../../vault
+  postgresql:
+    series: xenial
+    charm: cs:postgresql
+    num_units: 1
+relations:
+- - vault:db
+  - postgresql:db

src/tests/tests.yaml

@@ -6,6 +6,7 @@ configure:
 gate_bundles:
   - xenial-postgres
   - xenial-mysql
+  - bionic-postgres
 smoke_bundles:
   - xenial-mysql
 dev_bundles: