ci: Upgrade to Go 1.15

[francislavoie]

No description provided.

[francislavoie]

@mholt I was just curious whether we could try CI on unstable Go versions, and it seems to work... but the tests fail:

github.com/lucas-clemente/quic-go/internal/handshake.init.2()
	/home/runner/go/pkg/mod/github.com/lucas-clemente/[email protected]/internal/handshake/unsafe.go:26 +0x569
FAIL	github.com/caddyserver/caddy/v2/modules/caddyhttp/headers	0.042s
?   	github.com/caddyserver/caddy/v2/modules/caddyhttp/map	[no test files]
panic: qtls.ClientSessionState not compatible with tls.ClientSessionState

Is this something we can fix while keeping backwards-compat?

[francislavoie]

The binaries aren't much smaller - 2.5MB on linux, 3MB on mac, 2MB on windows. 🤔

[mholt]

Should be? Just looking from the error message it comes from a file that appears to use the unsafe package, so there's probably some voodoo that needs updating. @marten-seemann would know! I'm sure they'll support Go 1.15 once it's released...

The binaries aren't much smaller - 2.5MB on linux,

40 MB to 2.5 MB? Not bad! 😋

j/k... I suppose you meant size delta. 2.5 MB less for free (well, by simply upgrading Go) is pretty good!

[mholt]

@marten-seemann Would you be able to ping us when there's a new release that's compatible with Go 1.15? (We're getting test failures on Go 1.15 in the quic-go lib)

Go 1.15 was only released an hour ago -- there's no hurry. :)

[marten-seemann]

@mholt Yes, definitely. Will be some time later this week. I was planning to cut a new release of quic-go soon anyway - there've been a bunch of bug fixes and - which is important for Caddy - improvements to the QPACK compression efficiency.

[francislavoie]

Thanks @marten-seemann! I think that issue looks to be fixed with the latest release.

There is this new test failure though:

modules/caddyhttp/reverseproxy/fastcgi/client_test.go:252:24: conversion from int to string yields a string of one rune, not a string of digits (did you mean fmt.Sprint(x)?)
modules/caddyhttp/reverseproxy/fastcgi/client_test.go:269:24: conversion from int to string yields a string of one rune, not a string of digits (did you mean fmt.Sprint(x)?)
FAIL	github.com/caddyserver/caddy/v2/modules/caddyhttp/reverseproxy/fastcgi [build failed]

[mholt]

Cool, that error is a new feature of the Go 1.15 compiler.

Anyway, thanks Marten and Francis!

[mholt]

Great work on this, thanks again both of you!