Vitess Operator deploys VTAdmin in two separate containers running on the same pod. One for running the vtadmin-api and one for vtadmin-web. Please look at the architecture docs for details on how they interact with each other.
Vitess Operator then creates services on top of both vtadmin-api and vtadmin-web, which can be used to access them after either port-forwarding or assigning an external IP address to the service.
Finally, Vitess Operator creates the discovery.json file automatically which is needed to connect to vtctld and vtgate services. It connects to the global vtctld service and per-cell service of vtgates, both of which Vitess Operator creates automatically. No configuration from the users is required for discovering these components.
The VTAdmin configuration section lives at the same level as the vtctld configuration in the cluster specification.
The following options are available for configuring VTAdmin:
RBAC is a secret source. It is the role-based access control rules to use for VTAdmin API. More information on role-based access control can be found here.
Cells is a list of strings. It is the cells where VTAdmin must be deployed. Defaults to deploying instances of VTAdmin in all cells.
APIAddresses as a list of strings. Since the VTAdmin web UI runs on the client side, it needs the API address to use to query the API. We can't use the internal kubernetes service address or the ip of the pod, since they aren't visible outside the cluster. The API Address must be provided by the user based on how they export the service of VTAdmin API. In our example configuration (see below) we port-forward the service to port 14001 and therefore that is the address provided there. This value is a list because the address to be used for VTAdmin web in each cell might be different. If only 1 value is provided then, that is used for all the cells. The ideal way to deploy this would be to export each individual VTAdmin service (that we create) in each cell and attach external IPs to them and provide those IPs here.
Replicas - Number of VTAdmin deployments required per cell. We setup a service on top of the web and API connections, so load-balancing comes out of the box.
WebResources - Resource requests and limits for the container running the VTAdmin web server.
APIResources - Resource requests and limits for the container running the VTAdmin API server.
ReadOnly - Configuration to set the VTAdmin web UI to be read-only.
Apart from the VTAdmin configuration, the image to use for the containers also needs to be provided. Currently vitess/lite image doesn't contain the binaries to deploy vtadmin, so the more specific vitess/vtadmin image needs to be used.