> For the complete documentation index, see [llms.txt](https://arise-dream.gitbook.io/synology-notes/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://arise-dream.gitbook.io/synology-notes/container-manager/applications.md).

# Applications

Container Manager unites status monitoring, container image management, and resource management in a straightforward interface.

For more details see the [product page](https://www.synology.com/en-global/dsm/feature/container-manager).

## Maintenance

Updates on **containers** are automatically notified and handled by UI.

## Update Project

Projects updates are not handled by UI.

To update a single project:

* Project -> Select the project -> Action -> *Clean*
* Image -> Select the image(s) related to that project -> *Delete*
* Project -> Select the project -> Action -> *Build*

## Networking

If you set Firewall, remember to open all the traffic for the private subnet used by *Container Manager*.

Few scenarios e.g.:

* **Internet**
* **DBMS**, i.e. your container trying to reach a DB on host
* **DNS**, i.e. your container trying to identify another container in the same project
* **nginx**, i.e. expose your container using nginx

If you want to open the traffic for all subnet used typically by *Container Manager*, you could use the following subnet: `172.16.0.0/255.240.0.0`

### Double check connectivity

* Open a shell inside container: `docker exec -it mycontainer sh`
* Ping google.com: `ping google.com`
* Ping/nslookup another container in the same subnet: `nslookup anothercontainer`

**Note**: manually install **bind9-dnsutils** package for *nslookup* or **dnsutils-ping** for *ping* if needed.