log connection timeouts

wait for a maximum of ExitTimeout when shutting down

use github actions for ci

small collection of logging improvements

only emit active_at_termination if the conn is not idle

improve smokescreen error handling

goproxy: close after copy

Made requested changes

Log amount of time net.DialTimeout takes to establish the connection

Allow Yaml configuration options

add domain tag prefix

Fix markdown link typo in README.md for go modules

Add flag for proxy protocol if using smokescreen as a reverse proxy

Fix logging of project in CANONICAL-PROXY-DECISION

goproxy: don't log use of closed network connection errors

Update README with current help contents

Fix up Smokescreen build version

This comment was originally written in e1ec5a5 and was not
updated when the graceful shutdown code as overhauled in 804861d.

Update comment about how graceful socket closing works

Update README badge to use github actions test workflow

Add code coverage to our test workflow w/ goveralls

We should be testing on the two most recent Go versions

* Remove empty branch to appease staticcheck

This change is functionally a no-op.
Fix a nearby typo while we're at it.

* Check error in test

* Don't use t.Fatal or assert/require in goroutines

Attempting to fail a test doesn't work in goroutines. At best it might hit the
race detector. Instead, pass a `chan error` into any goroutines to return any
errors in.

Found via staticcheck

* Remove un-needed loop

Found with gosimple

* Use time.{Since,Until} instead of math with time.Now()

Style issue found with gosimple

* Len works on nil slices (returns 0), no check needed

Found with gosimple

* Remove redundant syntax

* Use TrimPrefix instead of doing it manually

Found with gosimple

* Bumping goproxy version

* Running go mod vendor

We log information about TCP connections accepted by the proxy or
created by the proxy, but we don't do it consistently.  We also use
terms like "src" and "dst", which are ambiguous in the context of two
TCP connections (the inbound connection from a client and the outbound
connection that we're making on behalf of the client).

This commit changes how we log TCP information, preferring terms like
"inbound," "outbound," "local," and "remote" to label the various pieces
of the IP+TCP 4-tuples.  It also adds the address and port number for
the local side of outgoing connections, to aid in debugging network
issues.  Finally, since we're changing these field names anyway, we will
prefer "addr" over "ip".

Subtree merge github.com/stripe/go-einhorn/einhorn package into internal/einhorn

I think it would be nice to be able to customize reject responses. This tiny change adds a RejectResponseHandler to the config struct, allowing you to show custom error responses

It can be used like this:

func main() {
	conf, _ := cmd.NewConfiguration(nil, nil)

	conf.RejectResponseHandler = func(resp *http.Response) {
		if resp.StatusCode == http.StatusProxyAuthRequired || resp.StatusCode == http.StatusForbidden {
			resp.Header.Set("X-Custom-Header", "some customer header")
		}
	}

bump go mod version to 1.15