Create Minio Interface Charm Library

Add Minio Interface Charm Library which uses
Serialized Data Interface Library.

config.yaml

@@ -1,11 +1,11 @@
 options:
   port:
-    type: string
-    default: '9000'
+    type: int
+    default: 9000
     description: HTTP port
   access-key:
     type: string
-    default: minio
+    default: 'minio'
     description: Access key
   secret-key:
     type: string

lib/charms/minio/v0/minio_interface.py

@@ -0,0 +1,38 @@
+"""
+Minio Interface
+
+This Interface requires the serialized-data-interface package
+please add it to your requirements.txt
+"""
+from provide_interface import ProvideAppInterface
+from require_interface import RequireAppInterface
+
+# The unique Charmhub library identifier, never change it
+LIBID = "7d0810fb78cf4afd81cc70118b27a127"
+
+# Increment this major API version when introducing breaking changes
+LIBAPI = 0
+
+# Increment this PATCH version before using `charmcraft push-lib` or reset
+# to 0 if you are raising the major API version
+LIBPATCH = 2
+
+# Serialized Data Schema for Minio Interface
+MINIO_SCHEMA = """
+service:
+  type: string
+port:
+  type: number
+access-key:
+  type: string
+secret-key:
+  type: string
+"""
+
+
+class MinioProvide(ProvideAppInterface):
+    SCHEMA = MINIO_SCHEMA
+
+
+class MinioRequire(RequireAppInterface):
+    SCHEMA = MINIO_SCHEMA

requirements.txt

@@ -1,2 +1,3 @@
 ops==1.1.0
 git+https://github.com/juju-solutions/resource-oci-image@1964d748022b762b9dce6e8bb7bdf12835102c72
+git+https://github.com/canonical/serialized-data-interface.git

src/charm.py

@@ -10,6 +10,7 @@
 from ops.model import ActiveStatus, MaintenanceStatus
 
 from oci_image import OCIImageResource, OCIImageResourceError
+from charms.minio.v0.minio_interface import MinioProvide
 
 log = logging.getLogger()
 
@@ -34,18 +35,28 @@ def gen_pass() -> str:
 class MinioCharm(CharmBase):
     def __init__(self, *args):
         super().__init__(*args)
+        self.minio_interface = MinioProvide(self, "minio")
         self.image = OCIImageResource(self, "oci-image")
         self.framework.observe(self.on.install, self.set_pod_spec)
         self.framework.observe(self.on.upgrade_charm, self.set_pod_spec)
         self.framework.observe(self.on.config_changed, self.set_pod_spec)
         self.framework.observe(self.on.minio_relation_joined, self.send_info)
 
     def send_info(self, event):
-        secret_key = get_or_set("password", default=gen_pass)
-        event.relation.data[self.unit]["service"] = self.model.app.name
-        event.relation.data[self.unit]["port"] = self.model.config["port"]
-        event.relation.data[self.unit]["access-key"] = self.model.config["access-key"]
-        event.relation.data[self.unit]["secret-key"] = secret_key
+        secret_key = get_or_set(
+            "password",
+            configured=self.model.config["secret-key"],
+            default=gen_pass(),
+        )
+
+        self.minio_interface.update_relation_data(
+            {
+                "service": self.model.app.name,
+                "port": self.model.config["port"],
+                "access-key": self.model.config["access-key"],
+                "secret-key": secret_key,
+            }
+        )
 
     def set_pod_spec(self, event):
         if not self.model.unit.is_leader():