Add docs on OSS update (#242)

* add update docs

* add oncall_db_migration pull

* add -f docker-compose.yml to pull command

* add --remove-orphans

* update -> update version header

README.md

@@ -56,6 +56,20 @@ Grafana Url: http://grafana:3000
 6. Enjoy! Check our [OSS docs](https://grafana.com/docs/grafana-cloud/oncall/open-source/) if you want to set up Slack, Telegram, Twilio or SMS/calls through Grafana Cloud. 
 
 
+## Update version
+To update your Grafana OnCall hobby environment:
+
+```shell
+# Update Docker images
+docker-compose --env-file .env_hobby -f docker-compose.yml pull engine celery oncall_db_migration
+
+# Re-deploy
+docker-compose --env-file .env_hobby -f docker-compose.yml up -d --remove-orphans
+```
+
+After updating the engine, you'll also need to click the "Update" button on the [plugin version page](http://localhost:3000/plugins/grafana-oncall-app?page=version-history).
+See [Grafana docs](https://grafana.com/docs/grafana/latest/administration/plugin-management/#update-a-plugin) for more info on updating Grafana plugins.
+
 ## Join community
 
 <a href="https://github.com/grafana/oncall/discussions/categories/community-calls"><img width="200px" src="docs/img/community_call.png"></a>

docs/sources/open-source.md

@@ -29,6 +29,11 @@ Check the [helm chart](https://github.com/grafana/oncall/tree/dev/helm/oncall) f
 
 We'll always be happy to provide assistance with production deployment in [our communities](https://github.com/grafana/oncall#join-community)! 
 
+## Update Grafana OnCall OSS
+To update an OSS installation of Grafana OnCall, please see the update docs:
+- **Hobby** playground environment: [README.md](https://github.com/grafana/oncall#update)
+- **Production** Helm environment: [Helm update](https://github.com/grafana/oncall/tree/dev/helm/oncall#update)
+
 ## Slack Setup
 
 The Slack integration for Grafana OnCall leverages Slack API features to provide a customizable and useful integration. Refer to the following steps to configure the Slack integration:

helm/oncall/README.md

@@ -144,6 +144,24 @@ externalRabbitmq:
   password:
 ```
 
+## Update
+```shell
+# Add & upgrade the repository
+helm repo add grafana https://grafana.github.io/helm-charts
+helm repo update
+
+# Re-deploy
+helm upgrade \
+    --install \
+    --wait \
+    --set base_url=example.com \
+    --set grafana."grafana\.ini".server.domain=example.com \
+    release-oncall \
+    grafana/oncall
+```
+
+After re-deploying, please also update the Grafana OnCall plugin on the plugin version page. See [Grafana docs](https://grafana.com/docs/grafana/latest/administration/plugin-management/#update-a-plugin) for more info on updating Grafana plugins.
+
 ## Uninstall
 ### Uninstalling the helm chart
 ```bash