how can I pass parameters to go build when exec ko publish

[tsunhua]

In my Go project, I use go build -tags 'dev' to build dev version, and use go build -tags 'prod' to build production version. When I called ko publish ., it told me that failed to publish images: importpath "git.xxx.com/my-project" is not supported

I know that ko will call go build, but how can I pass -tags 'dev' to go build when exec ko publish?

[jonjohnsonjr]

We don't do a great job of passing through flags to the underlying go build invocation.

Somewhat related: #54 and #52

I dug around for a bit looking for the go build -tags parsing and ran across golang/go@80e7832, which taught me two things:

1. This tags flag is changing from space-separated to comma-separated in 1.13.
2. GOFLAGS exists, which should let you work around this (for now).

Now, this isn't that great:

$ GOFLAGS="-tags=dev" ko publish .

Ideally you could just do this:

$ ko publish -tags=dev .

But that is going to be tough... we currently have another flag (--tags, -t) that allows you to specify how the image is tagged in your registry, so the way the above command is getting parsed right now is equivalent to:

$ ko publish -t "ags=dev" .

This fails because ags=dev isn't a valid image tag. If we want to support that, we'll need to change how we handle flag parsing a bit. It might be possible to maintain a go build FlagSet, and do a first pass over argv before handing off flag parsing to cobra, but I haven't looked into it much.

I'm a little worried that the intersection of our flags, go's flags, and kubectl's flags is going to be a maintenance nightmare, but I'm sure we can figure something out.

[dprotaso]

What about an all encompassing flag for build args?

ie. -build-args "-tag 'dev'"

[dprotaso]

The above being a catch-all while more common options could should promoted to first level flags.

[jonjohnsonjr]

That doesn't seem like a big improvement over GOFLAGS.

[dprotaso]

I definitely missed the second point :( Yeah I agree - GOFLAGS accomplishes that

…

On Wed, Aug 14, 2019 at 12:57 PM jonjohnsonjr ***@***.***> wrote: That doesn't seem like a big improvement over GOFLAGS. — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#69>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAAERAT2LESIOXB6L4S2GNDQEQ2RPANCNFSM4ILGX7VQ> .

[jonjohnsonjr]

I think GOFLAGS is sufficient for this for now, going to close this. Feel free to reopen if that doesn't work (or you have a better idea).

[cameronbraid]

GOFLAGS isnt sufficient for : GOFLAGS="-ldflags=-Xmain.version=1.2.3"

I get flag provided but not defined: -Xmain.version

[jonjohnsonjr]

GOFLAGS isnt sufficient for : GOFLAGS="-ldflags=-Xmain.version=1.2.3"

Does this work?

GOFLAGS="-ldflags=-X=main.version=1.2.3

[cameronbraid]

Yep, thanks heaps

cmd/server/main.go

package main
import (
	"fmt"
)
var Version = "dev"
func main() {
	fmt.Println("version " + Version)
}

go build ./cmd/server; ./server

prints version dev

go build -ldflags="-X=main.Version=1.2.3" ./cmd/server; ./server

printsversion 1.2.3

x=`KO_DOCKER_REPO=ko.local GOFLAGS="-ldflags=-X=main.Version=1.2.3" ko publish ./cmd/server; docker run --rm -it $x

prints
version 1.2.3