Detect when connection to dcrd is not available and display outage http view

[raedah]

trafficstars

When connection to dcrd is lost or unavailable, display a msg to web visitors about an outage.

[chappjc]

Currently a lost dcrd connection is bad news and there is currently a PR to disable autoreconnect: https://github.com/decred/dcrdata/pull/1130 In the future, a better solution that detects disconnect and reconnect can perhaps be implemented, but that's presently not straightforward.

[ukane-philemon]

@chappjc, how do we want this to be? A mini banner with a message on the UI and a message to API consumers?

[chappjc]

I'd say something down at the bottom near the red/green indicator. Maybe orange with next next to it. But, meh

[ukane-philemon]

I'd say something down at the bottom near the red/green indicator. Maybe orange with next next to it. But, meh

Okay, then how about API consumers?

[chappjc]

I'd say something down at the bottom near the red/green indicator. Maybe orange with next next to it. But, meh

Okay, then how about API consumers?

I'd have to check, but I think the "ready" flag already handles this.

[ukane-philemon]

I think the "ready" flag already handles this.

It should but I don't think it is set when we fail to update connections(which will fail if the node is disconnected).

I'm thinking c.Status should be set to false if we fail at line 167.

https://github.com/decred/dcrdata/blob/master/cmd/dcrdata/internal/api/apiroutes.go#L166-#L200