Export GOBIN env var

[sslavic]

Please have GOBIN environment var defined in the Golang Docker images, so that go install works without -o switch.

Now it fails with:
go install: no install location for .go files listed on command line (GOBIN not set)

[tianon]

Check that your code is inside GOPATH: https://stackoverflow.com/a/25216795/433558

[sslavic]

Yes, it is.

Repro steps:

$ docker run -it --rm --name test golang:1 bash
$ go get github.com/nats-io/go-nats-streaming
$ go install /go/src/github.com/nats-io/go-nats-streaming/examples/stan-pub.go

Last command fails for me with
go install: no install location for .go files listed on command line (GOBIN not set)

If after that I do:

export GOBIN=$GOPATH/bin
go install /go/src/github.com/nats-io/go-nats-streaming/examples/stan-pub.go

Install now passes, binary gets stored in /go/bin.

To fix this, in all golang Docker files probably it should be enough to add after lines like https://github.com/docker-library/golang/blob/master/1.9/stretch/Dockerfile#L46 something like

ENV GOBIN $GOPATH/bin

[yosifkit]

Later answers in the linked stackoverflow are the key: https://stackoverflow.com/a/36717762 and https://stackoverflow.com/a/39952720.

Actually there are 2 different kinds of behavior.

go install <package>

this is documented in Compile and install packages and dependencies You don't need GOBIN if you set GOPATH correctly.

go install <gofile>

this is not documented and you need GOBIN env variable in this mode.

So I would say that if you are using go install on a .go file, then you should set GOBIN, since it is not a documented use of go install.

$ go install --help
usage: install [build flags] [packages]

Install compiles and installs the packages named by the import paths,
along with their dependencies.

For more about the build flags, see 'go help build'.
For more about specifying packages, see 'go help packages'.

See also: go build, go get, go clean.

[sslavic]

@yosifkit thanks for heads up. go install --help mentions

For more about specifying packages, see 'go help packages'.

go help packages among other things states:

As a special case, if the package list is a list of .go files from a
single directory, the command is applied to a single synthesized
package made up of exactly those files, ignoring any build constraints
in those files and ignoring any other files in the directory.

So I understand this that go install is also for .go files. Problem is inconsistency, in case of package name provided GOBIN is not required while in case .go file is being installed GOBIN is being required.
I've reported this issue on golang/go#23439

Another problem is that github.com/nats-io/go-nats-streaming/examples has multiple apps, each should be in it's own package/dir for current go install for each app to work with current go and without GOBIN being set.
For that I reported https://github.com/nats-io/go-nats-streaming/issues/164

Still I think it would not only not harm to have GOBIN explicitly set in golang Docker images, it would be helpful to better handle the inconsistencies.

[tianon]

If we set GOBIN in the image, then images which set GOPATH to something other than our default value (or add an additional path) will need to either unset GOBIN or modify GOBIN to point to their new directory, so I'm still not comfortable adding it to the image (since it will automatically default to GOPATH/bin, which will change depending on which component of the multi-directory GOPATH value we're building in, etc).

[sslavic]

NATS Streaming examples have been fixed, each example was refactored to be in it's own package/dir so documented go install <package> variant works without GOBIN being defined.

It seems fix for inconsistency in go install variants is scheduled for Go 1.11 so GOBIN will likely not be needed also for the variant when .go file is passed as argument.

I also understand concerns @tianon mentioned.

AFAIC this issue can be closed.