Add initial .devcontainer for go 1.19

[jmhbnz]

When the devcontainer starts it will run make build to ensure compiled etcd binaries are immediately available for use.

I've confirmed make test is also successfully running unit and integration tests within the container.

Standard etcd ports are forwarded in-case the user wants to interact with the etcd components from outside the container.

This is just an initial proposal and creates a foundation that other contributors can add to moving forward.

Fixes #15377

[serathius]

cc @ahrtr

[ahrtr]

Thanks @jmhbnz

A quick question, did you follow https://github.com/devcontainers/cli#try-out-the-cli ?

cc @craiglpeters

[jmhbnz]

A quick question, did you follow https://github.com/devcontainers/cli#try-out-the-cli ?

Yep - works great :)

See below - running from the root of cloned etcd directory that has this .devcontainer present:

 james   feat/add_devcon.. 
 ➜ devcontainer up --workspace-folder .                                                                                         
[10 ms] @devcontainers/cli 0.31.0. Node.js v19.7.0. linux 6.1.11-76060111-generic x64.
{"outcome":"success","containerId":"62b00884d2852165077a28d131c1a898e3bbfc0251e469d705e648675621884f","remoteUser":"vscode","rem
oteWorkspaceFolder":"/workspaces/etcd"}


 james   feat/add_devcon..                                                                                         22:17:49 
 ➜ devcontainer exec --workspace-folder . make build
GO_BUILD_FLAGS=" -v" ./scripts/build.sh
Running etcd_build
% 'rm' '-f' 'bin/etcd'
% (cd server && 'env' 'CGO_ENABLED=0' 'GO_BUILD_FLAGS= -v' 'GOOS=' 'GOARCH=' 'go' 'build' '-v' '-trimpath' '-installsuffix=cgo' '-ldflags=-X=go.etcd.io/etcd/api/v3/version.GitSHA=f2bd3154a' '-o=../bin/etcd' '.')
stderr: go.etcd.io/etcd/server/v3
% 'rm' '-f' 'bin/etcdutl'
% (cd etcdutl && 'env' 'GO_BUILD_FLAGS= -v' 'CGO_ENABLED=0' 'GO_BUILD_FLAGS= -v' 'GOOS=' 'GOARCH=' 'go' 'build' '-v' '-trimpath' '-installsuffix=cgo' '-ldflags=-X=go.etcd.io/etcd/api/v3/version.GitSHA=f2bd3154a' '-o=../bin/etcdutl' '.')
stderr: go.etcd.io/etcd/etcdutl/v3
% 'rm' '-f' 'bin/etcdctl'
% (cd etcdctl && 'env' 'GO_BUILD_FLAGS= -v' 'CGO_ENABLED=0' 'GO_BUILD_FLAGS= -v' 'GOOS=' 'GOARCH=' 'go' 'build' '-v' '-trimpath' '-installsuffix=cgo' '-ldflags=-X=go.etcd.io/etcd/api/v3/version.GitSHA=f2bd3154a' '-o=../bin/etcdctl' '.')
stderr: go.etcd.io/etcd/etcdctl/v3
SUCCESS: etcd_build (GOARCH=)
./bin/etcd --version
etcd Version: 3.6.0-alpha.0
Git SHA: f2bd3154a
Go Version: go1.19.6
Go OS/Arch: linux/amd64
./bin/etcdctl version
etcdctl version: 3.6.0-alpha.0
API version: 3.6
./bin/etcdutl version
etcdutl version: 3.6.0-alpha.0
API version: 3.6
{"outcome":"success"}

[ahrtr]

Please @craiglpeters take a look, thx

[ahrtr]

Thanks both @craiglpeters and @jkeech , could you please approve this PR if no any other objections or comments?

[ptabor]

LGTM. I don't think we need to engage github engineers for low-risk and streightforward use-case.

[ahrtr]

Thank you @jkeech