rename init packages and onboard init to go modules

[lydiafilipe]

Summary

This onboards ecs-init to go modules. There are quite a few changes here, to summarize them

• replace ecs init path references in scripts/init package
• created the go module and go sum files
• vendor directory updated
• dep-related files and make target removed
• tweaked the gobuild script to remove setting gopath

Implementation details

Replaced the ecs init package paths by running grep -rl github.com/aws/amazon-ecs-init . | xargs sed -i 's/github.com\/aws\/amazon-ecs-init/github.com\/aws\/amazon-ecs-agent/g'

Onboarded to go modules with
go mod init
go mod tidy

Had to add a replacement: replace github.com/coreos/go-systemd => github.com/coreos/go-systemd/v22 v22.0.0. This is due to a dependency on github.com/docker/go-plugins-helpers, which has not onboarded to go modules or semantic versioning for some of its imports.

After that, ran go mod tidy again. Had to replace some packages for which the versioned changed compared to what was in our dep files.

Then deleted the vendor directory and ran go mod vendor.

Additionally, had to remove setting GOPATH in our init build script (since that cases conflicts when using go modules). Also removed dep stuff in Makefile.

Testing

• made/tested the change in the init package itself
• successfully ran make rpm-in-docker and make generic-rpm in that package, and used the former rpm in an ami build (against which I ran functional tests)
• built changes in Koji and, similarly to above, used the result rpms in ami builds and ran functional tests against those

I replicated those changes in this repository.

Also verified the github workflow for the same changes in the init repository succeeds

New tests cover the changes: no

Description for the changelog

rename init packages and onboard init to go modules

Licensing

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[fierlion]

Looks good!

[chienhanlin]

Q. See some golang.org files are empty, like ecs-init/vendor/golang.org/x/sys/unix/mksyscall.pl, are they supposed to be empty? Thanks!

[lydiafilipe]

Q. See some golang.org files are empty, like ecs-init/vendor/golang.org/x/sys/unix/mksyscall.pl, are they supposed to be empty? Thanks!

Interesting that they are empty in the diff, they are not actually empty locally or in my branch - (eg https://github.com/lydiafilipe/amazon-ecs-agent/blob/init-gomodules/ecs-init/vendor/golang.org/x/sys/unix/mksyscall.pl). Regardless, these were all generated automatically by go mod vendor