moving to Dar es Salaam

My partner and I are looking to move to Dar es Salaam with my job. This area is new to me and we would like to know is there an ex pat community, is it safe, good restaurants or night life. How are the beaches etc. Is it easy to buy shopping and groceries and is it expensive??

How is the fitness industry? Any fitness clubs or yoga classes etc. Which is the best area to live in, we have heard Oysterbay or Masaki? Are there any other recommendations.

Thank you for your assistance with this. Making a decision to move to a new area is always challenging and information greatly received.
kind regards,
Evert and Debbie