Add helm 2.7.2

Once we have helm in the core origin, the Helm exporter can then depend on
this and be able to use this binary from the studio. This would mean that
the exporter can then take care of the `helm dep up` command for you.

Signed-off-by: Zeeshan Ali <zeeshan@kinvolk.io>

.bldr.toml

@@ -330,6 +330,8 @@ plan_path = "handlebars-cmd"
 plan_path = "haproxy"
 [harfbuzz]
 plan_path = "harfbuzz"
+[helm]
+plan_path = "helm"
 [htop]
 plan_path = "htop"
 [httpd]

helm/README.md

@@ -0,0 +1,10 @@
+Helm
+====
+
+This is a Habitat plan for the Kubernetes Helm client CLI application, called `helm`.
+
+Usage
+=====
+
+Please consult the [official documentation](https://docs.helm.sh/using_helm/) for information on how
+to use `helm`.

helm/plan.sh

@@ -0,0 +1,55 @@
+go_pkg="k8s.io/helm"
+
+pkg_name=helm
+pkg_origin=core
+pkg_version="2.7.2"
+pkg_description="Helm is a tool for managing Kubernetes charts"
+pkg_maintainer="The Habitat Maintainers <humans@habitat.sh>"
+pkg_license=("Apache-2.0")
+pkg_source="https://$go_pkg"
+pkg_upstream_url=$pkg_source
+pkg_scaffolding="core/scaffolding-go"
+pkg_bin_dirs=(bin)
+pkg_build_deps=(
+  core/which
+  core/coreutils
+  core/mercurial
+)
+scaffolding_go_build_deps=()
+# note: helm uses github.com/Masterminds/glide but `make bootstrap` we launch as
+# part of the build below, takes care of that for use.
+
+do_prepare() {
+  build_line "mkdir -p \$GOPATH/bin; export PATH=\$GOPATH/bin:\$PATH"
+  mkdir -p "$GOPATH/bin"
+  export PATH=$GOPATH/bin:$PATH
+}
+
+do_download() {
+  # `-d`: don't let go build it, we'll have to build this ourselves
+  # also, don't have `go get` bail when not finding a package in that directory
+  build_line "go get -d $go_pkg"
+
+  go get -d $go_pkg 2>&1 | grep -q "no Go files"
+
+  pushd "$scaffolding_go_pkg_path"
+    git reset --hard v$pkg_version
+  popd
+}
+
+do_build() {
+  # For some reason one of the commands in the Makefile launches env with an
+  # absolute path so we need to ensure it can find it there.
+  build_line "ln -fs \"$(which env)\" /usr/bin/env"
+  ln -fs "$(which env)" /usr/bin/env
+
+  pushd "$scaffolding_go_pkg_path"
+    build_line "make bootstrap build"
+    make bootstrap build
+  popd
+}
+
+do_install() {
+  build_line "copying Helm binary"
+  cp -f "${scaffolding_go_pkg_path:?}/bin/helm" "$pkg_prefix/bin"
+}