What environment variable overrides the CLI's default Vault server address?

The `VAULT_ADDR` environment variable is the standard and well-documented way to specify the address of the Vault server for the CLI and client libraries. Setting this variable allows users to connect to a specific Vault instance without explicitly providing the address in every command, such as `vault login` or `vault kv get`.

`VAULT_HTTP_ADDRESS` is not the standard environment variable used by Vault clients to specify the server address; `VAULT_ADDR` is the correct one.

`VAULT_ADDRESS` is a generic name and not the specific environment variable recognized by the Vault CLI for specifying the server address.

`VAULT_HTTPS_ADDRESS` is not the standard environment variable used by Vault clients; `VAULT_ADDR` handles both HTTP and HTTPS based on the URI scheme.