Once you have your Docker template deployed and properly configured, you receive a fully functional and stable application. However, the majority of Dockerized applications and services are continuously developed, delivering new product versions (implemented within tags) from time to time. Thus, most likely, eventually you’ll need to update your already running template to its latest version.With Jelastic, such redeploy operation could be performed just in a few clicks, whilst providing the following benefits:
- data, stored within the mounted to a container volumes, can remain available afterwards through being packed into separate .tar.gz archives, which are automatically transferred out/in the container to the host physical server during this operation
- all the previously specified custom configurations (like run commands, links, variables, etc) and files in /var/lib/jelastic directory (required by Jelastic to ensure container operability) won’t be affected
- if operating with multiple template instances (i.e. in case it was scaled horizontally), the update can be performed implicitly and causing no downtime through redeploying the containers one by one
Also, depending on a used software stack, some of container configuration files will be automatically saved and re-applied to your updated instance(s) afterward. Such files are listed within a dedicated redeploy.conf configuration file, where you can also set paths to your customized configs and/or user data which you’d like to keep during container update(s) in a similar way.
And now let’s consider how to actually perform the container update with another tag version either directly through the developers dashboard using GUI or remotely, with the help of Jelastic API and CLI.