Track Duration

We would like to provide build/deploy/pipeline duration as a metric on the Analytics page. I picture a few ways that this could work.

Initially we could crudely get the duration from getting the 'Deployed' status timestamp and subtracting the 'Deploying' status timestamp from the matching Application/Service/Environment/Version. This would not require any schema changes, or updating anything besides the specific query on the Analytics page.

Since I think this call will get expensive over time, the other option we have is to make this calculation as part of the `/deploy` endpoint. This would allow us to store the pre-computed duration in the log, and possible also in the service if we want to display the value on the Dashboard. I think this is the better long term play, but perhaps we can work this as a future ticket since I'd like to do a bit more research.

從 Analytics page 的 query 和 /deploy endpoint 開始，接著追蹤相符的 Application/Service/Environment/Version 之 Deployed 與 Deploying 狀態時間戳。比較 query 時計算與在 log 或 service 中儲存預先計算的 duration。完成的標準是 Analytics page 公開 build、deploy 或 pipeline duration，並採用有文件記錄的方法及適當的驗證。

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