refactor(deploy): mount database_url.txt as file and run migrate command in shell under /bin/ash -c

deploy/templates/migration-job.yaml

@@ -25,17 +25,22 @@ spec:
       containers:
         - name: migrations
           image: "{{ .Values.migrations.image.repository }}:{{ .Values.migrations.image.tag }}"
-          command: ["/usr/local/bin/migrate"]
-          args: ["-path", "/srv/migrations/", "-database", "$MIGRATE_DATABASE_URL", "up"]
-          env:
-            - name: MIGRATE_DATABASE_URL
-              valueFrom:
-                secretKeyRef:
-                  name: {{ .Release.Name }}
-                  key: "database_url.txt"
+          command: ["/bin/ash"]
+          args:
+            - -c
+            - |
+              migrate -path /srv/migrations -database $(cat /etc/yggdrasil/secrets/database_url.txt) up
           {{- with .Values.migrations.resources }}
           resources:
             {{- toYaml . | nindent 12 }}
           {{- end }}
+          volumeMounts:
+            - mountPath: /etc/yggdrasil/secrets
+              name: secrets
+              readOnly: true
+      volumes:
+        - name: secrets
+          secret:
+            secretName: {{ .Release.Name }}
       restartPolicy: Never
   backoffLimit: 0