Fix katib-manager crash in kubeflow cluster

[hougangliu]

In kubeflow cluster, there is a service named "mysql" from pipeline. so in each kubeflow POD, there is will ENV for mysql service like below, which will make getDbName() return in katib mysql DB invalid (owning to env MYSQL_PORT)

# env|grep MYSQL
MYSQL_PORT_3306_TCP_ADDR=10.0.251.111
MYSQL_PORT_3306_TCP_PORT=3306
MYSQL_SERVICE_HOST=10.0.251.111
MYSQL_PORT_3306_TCP_PROTO=tcp
MYSQL_HOST=katib-db.kubeflow
MYSQL_PORT=tcp://10.0.251.111:3306
MYSQL_SERVICE_PORT=3306
MYSQL_PORT_3306_TCP=tcp://10.0.251.111:3306

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This change is 

[hougangliu]

/cc @gaocegege @johnugeorge

[johnugeorge]

Great! what we suspected about env var.

Still, how does env variable get propagated into Katib pod?

[hougangliu]

Still, how does env variable get propagated into Katib pod?

it is Kubernetes feature, all services in the same namespace will be imported into the Pods as env

[gaocegege]

Ref https://kubernetes.io/docs/concepts/services-networking/service/#environment-variables

[gaocegege]

/lgtm

[johnugeorge]

/approve

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