You Do Need power plug adapter while traveling from Djibouti to Cocos (Keeling) Islands.

Here is Why You Need An Adapter

The outlet and plug type used in Cocos (Keeling) Islands is I and in Djibouti are C and E. This is how they look like.

Djibouti

In Djibouti, outlets of type C and E are in use.

Type C

Type E

Cocos (Keeling) Islands

In Cocos (Keeling) Islands, outlets of type I are in use.

Type I