Convert charm to operator framework (#6)

.github/workflows/test-microk8s.yaml

@@ -22,7 +22,7 @@ jobs:
       run: black --check .
 
     - name: Check flake8
-      run: flake8 .
+      run: flake8 . --max-line-length 100
 
   test:
     name: Test
@@ -39,7 +39,7 @@ jobs:
     - name: Install dependencies
       run: |
         set -eux
-        sudo snap install charm --classic
+        sudo pip3 install charmcraft
         sudo snap install juju --classic
         sudo snap install juju-wait --classic
 
@@ -52,10 +52,10 @@ jobs:
     - name: Deploy MinIO
       run: |
         set -eux
-        charm build .
-        juju deploy /tmp/charm-builds/minio \
-            --config secret-key=minio-secret-key \
-            --resource oci-image=minio/minio:RELEASE.2018-02-09T22-40-05Z
+        charmcraft build
+        juju deploy ./minio.charm \
+          --config secret-key=minio-secret-key \
+          --resource oci-image=minio/minio:RELEASE.2021-02-07T01-31-02Z
         juju wait -wvt 300
 
     - name: Test MinIO
@@ -71,7 +71,7 @@ jobs:
         "mc alias set ci http://minio.minio.svc.cluster.local:9000 minio minio-secret-key && mc mb ci/foo && mc rb ci/foo"
 
 
-    - name: Get pod statuses
+    - name: Get all
       run: kubectl get all -A
       if: failure()
 

.gitignore

@@ -0,0 +1,2 @@
+*.charm
+build/

config.yaml

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

metadata.yaml

@@ -17,10 +17,10 @@ resources:
     type: oci-image
     description: Backing OCI image
     auto-fetch: true
-    upstream-source: minio/minio:RELEASE.2018-02-09T22-40-05Z
+    upstream-source: minio/minio:RELEASE.2021-02-07T01-31-02Z
 provides:
   minio:
-    interface: generic-ip-port-user-pass
+    interface: minio
 storage:
   minio-data:
     type: filesystem

requirements.txt

@@ -0,0 +1,2 @@
+ops==1.1.0
+git+https://github.com/juju-solutions/resource-oci-image@1964d748022b762b9dce6e8bb7bdf12835102c72

src/charm.py

@@ -0,0 +1,96 @@
+#!/usr/bin/env python3
+
+import logging
+from pathlib import Path
+from random import choices
+from string import ascii_uppercase, digits
+from typing import Optional
+from ops.charm import CharmBase
+from ops.main import main
+from ops.model import ActiveStatus, MaintenanceStatus
+
+from oci_image import OCIImageResource, OCIImageResourceError
+
+log = logging.getLogger()
+
+
+def get_or_set(name: str, *, configured: Optional[str], default: str) -> str:
+    if configured:
+        Path(f"/run/{name}").write_text(configured)
+        return configured
+
+    try:
+        path = Path(f"/run/{name}")
+        return path.read_text()
+    except FileNotFoundError:
+        path.write_text(default)
+        return default
+
+
+def gen_pass() -> str:
+    return "".join(choices(ascii_uppercase + digits, k=30))
+
+
+class MinioCharm(CharmBase):
+    def __init__(self, *args):
+        super().__init__(*args)
+        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
+
+    def set_pod_spec(self, event):
+        if not self.model.unit.is_leader():
+            log.info("Not a leader, skipping set_pod_spec")
+            self.model.unit.status = ActiveStatus()
+            return
+
+        try:
+            image_details = self.image.fetch()
+        except OCIImageResourceError as e:
+            self.model.unit.status = e.status
+            log.info(e)
+            return
+
+        secret_key = get_or_set(
+            "password",
+            configured=self.model.config["secret-key"],
+            default=gen_pass(),
+        )
+
+        self.model.unit.status = MaintenanceStatus("Setting pod spec")
+        self.model.pod.set_spec(
+            {
+                "version": 3,
+                "containers": [
+                    {
+                        "name": "minio",
+                        "args": ["server", "/data"],
+                        "imageDetails": image_details,
+                        "ports": [
+                            {
+                                "name": "minio",
+                                "containerPort": int(self.model.config["port"]),
+                            }
+                        ],
+                        "envConfig": {
+                            "MINIO_ACCESS_KEY": self.model.config["access-key"],
+                            "MINIO_SECRET_KEY": secret_key,
+                        },
+                    }
+                ],
+            }
+        )
+        self.model.unit.status = ActiveStatus()
+
+
+if __name__ == "__main__":
+    main(MinioCharm)