Small improvements for VM configuration documentation (#37)

* Fix BAO_ADDR environment variable

Signed-off-by: hashworks <mail@hashworks.net>

* Add note for snapshots of larger databases that might exceed the default timeout

Signed-off-by: hashworks <mail@hashworks.net>

* Reference bao instead of vault where possible

The BAO_CLIENT_TIMEOUT environment variable isn't documented, but
supported.

https://github.com/openbao/openbao/blob/main/api/client.go#L41C30-L41C48
Signed-off-by: hashworks <mail@hashworks.net>

---------

Signed-off-by: hashworks <mail@hashworks.net>

Author: hashworks

docs/vm-configuration.md

@@ -62,7 +62,7 @@ api_proxy {
 listener "unix" {
   # Expose OpenBao Agent API seperately
   # https://openbao.org/docs/agent-and-proxy/agent/caching/#configuration-listener
-  address = "/etc/vault.d/agent.sock"
+  address = "/etc/bao.d/agent.sock"
   tls_disable = true
 }
 
@@ -131,7 +131,7 @@ cat << 'EOF' > /usr/local/bin/bao-snapshot
 #  - /etc/bao.d/bao_snapshot_agent.hcl
 #  - /etc/systemd/system/bao-agent.service
 
-BAO_ADDR="BAO_ADDR=unix:///etc/bao.d/agent.sock" \
+BAO_ADDR="unix:///etc/bao.d/agent.sock" \
 /usr/local/bin/bao operator raft snapshot save "/opt/bao/snapshots/bao-raft_$(date +%F-%H%M).snapshot"
 EOF
 ```
@@ -151,9 +151,11 @@ echo "0 * * * * root /usr/local/bin/bao-snapshot" >> /etc/crontab
 Test the script (errors probably in `/var/spool/mail/root`):
 
 ```bash
-vault-snapshot
+bao-snapshot
 ```
 
+For users with larger databases this might fail with `context deadline exceeded`, which can be solved by increasing the `BAO_CLIENT_TIMEOUT` environment variable (default 60s) for the [agent service](https://www.freedesktop.org/software/systemd/man/latest/systemd.exec.html#Environment).
+
 ## Sync with remote storage
 
 ### S3