pass 6 specific env vars to make_mycnf hook

[deepthi]

The env variables that are being passed to make_mycnf are:
KEYSPACE
SHARD
TABLET_TYPE
TABLET_ID
TABLET_DIR

Edit: Added one more:
MYSQL_PORT

Signed-off-by: deepthi deepthi@planetscale.com

[sougou]

For consistency, let's uppercase tablet_type, etc in examples/*/vttablet-up.sh scripts. People often doctor those scripts for prod usage, and may miss this subtlety.

[sjmudd]

It looks like a minimum of MYSQL_PORT is also needed to enable the my.cnf file to be configured exclusively from the make_mycnf hook.

If the hook were also to have access to the exported members of the Mycnf struct then any user configuration overrides would also be seen by the hook and could be taken into account. That obviously would require more settings to be exposed.

[deepthi]

Actually the scripts are already consistent. Environment variables are uppercase and local script variables are lowercase. tablet_type is a local variable in these scripts.

For consistency, let's uppercase tablet_type, etc in examples/*/vttablet-up.sh scripts. People often doctor those scripts for prod usage, and may miss this subtlety.

[deepthi]

@derekperkins Can you take a look at the change to the examples? Do we want to make a similar change for the kubernetes example?

[sougou]

Let's get this through. If fixes are needed in k8s, we can do that later.

[sjmudd]

+1