feat(rootfs/Dockerfile): add goss tool for validating server configs (#285)

See https://github.com/aelsabbahy/goss/releases/tag/v0.3.16

Author: mboersma

README.md

@@ -18,6 +18,7 @@ creating [issues][] and submitting [pull requests][].
 * [ginkgo][]: BDD testing framework for Go
 * [go-bindata][]: converts any file into Go source code
 * [golangci-lint][]: concurrent runner for Go linting tools
+* [goss][]: YAML-based tool for validating a server's configuration
 * [gox][]: simple Go cross-compiling tool
 * [helm][]: Kubernetes package manager
 * [jq][]: command-line JSON processor
@@ -97,6 +98,7 @@ You will be prompted to confirm again before any tag or release is written to Gi
 [Go]: https://golang.org/
 [go-dev index URL]: https://mcr.microsoft.com/v2/oss/azcu/go-dev/tags/list
 [golangci-lint]: https://github.com/golangci/golangci-lint
+[goss]: https://github.com/aelsabbahy/goss
 [gox]: https://github.com/mitchellh/gox
 [helm]: https://github.com/kubernetes/helm
 [issues]: https://github.com/deis/docker-go-dev/issues

rootfs/Dockerfile

@@ -9,6 +9,7 @@ ENV ANSIBLE_VERSION=2.10.3 \
     ETCDCTL_VERSION=v3.1.8 \
     GO_VERSION=1.16.3 \
     GOLANGCI_LINT_VERSION=v1.39.0 \
+    GOSS_VERSION=v0.3.16 \
     HELM_VERSION=3.5.4 \
     KUBECTL_VERSION=v1.18.18 \
     PACKER_VERSION=1.6.1 \
@@ -102,6 +103,10 @@ RUN \
     && unzip /tmp/packer.zip -d /usr/local/bin \
   && curl -o /usr/local/bin/shfmt -sSL https://github.com/mvdan/sh/releases/download/v{SHFMT_VERSION}/shfmt_v{SHFMT_VERSION}_linux_amd64 \
   && chmod +x /usr/local/bin/shfmt \
+  && curl -L "https://github.com/aelsabbahy/goss/releases/download/${GOSS_VERSION}/goss-linux-amd64" -o /usr/local/bin/goss \
+  && chmod +rx /usr/local/bin/goss \
+  && curl -L "https://github.com/aelsabbahy/goss/releases/download/${GOSS_VERSION}/dgoss" -o /usr/local/bin/dgoss \
+  && chmod +rx /usr/local/bin/dgoss \
   && pip3 install --disable-pip-version-check --no-cache-dir --upgrade pip \
   && pip3 install --disable-pip-version-check --no-cache-dir azure-cli==${AZCLI_VERSION} PyJWT==${PYJWT_VERSION} shyaml ansible==${ANSIBLE_VERSION} pywinrm==${PYWINRM_VERSION} \
   && apt-get purge --auto-remove -y libffi-dev python3-dev \