Apisix-dashboard: feat: embed all generated web assets into api binary

[hnlq715]

Feature request

Embed all generated web assets into api binary, so it would be convenient to run or deploy the dashboard.

Just like grafana.

[hnlq715]

I did a simple test with go-bindata, the api binary size increases about 4MB

I think this should be acceptable :-)

Before

-rwxr-xr-x 1 root root 27M Jan 29 09:02 output/manager-api

After

-rwxr-xr-x 1 root root 31M Jan 29 09:42 output/manager-api

[hnlq715]

And the origin html files have 15M

➜  apisix-dashboard git:(master) ✗ du -sh output/html
15M     output/html

[starsz]

That's sounds so great. PRs are welcomed.

[imjoey]

@hnlq715 this is great and I love this feature. Thanks and looking forward to your contributions. 😄

[hnlq715]

@starsz @imjoey Get it

[nic-chen]

looking forward to it，thanks

[bisakhmondal]

Hii all, can I open a PR here? Yesterday I was giving it a casual try after a bit of conversation with @nic-chen and It seems I have completed the goal😅. Dev branch link
Go 1.16 release has official support for embedding static files into generated go binary. Here's the release notes. Just FYI, the package go-bindata has been achieved and not been maintained for a long time. So I went with the new embed package and go:embed directive of go 1.16.
here's the stats

plain binary

🔥➜ output git:(embed_assets) du -h manager-api
26M manager-api

web assets

🔥➜ output git:(embed_assets) du -sh html       
18M html

binary with web assets

🔥➜ output git:(embed_assets) du -h manager-api 
44M manager-api

Thanks :)

[hnlq715]

nice job