Dockerfile to create an image which can run kops, kubectl and kustomize commands

Dockerfile

# Use a builder layer while adding ecr-login to minimise the size of final image
FROM golang:alpine AS builder
RUN apk --no-cache add git && \
    git clone https://github.com/awslabs/amazon-ecr-credential-helper /go/src/github.com/awslabs/amazon-ecr-credential-helper && \
    go build -o /assets/docker-credential-ecr-login github.com/awslabs/amazon-ecr-credential-helper/ecr-login/cli/docker-credential-ecr-login

FROM alpine AS resource
COPY --from=builder /assets/docker-credential-ecr-login /usr/local/bin/docker-credential-ecr-login

# OpenSSH is required to create a ssh key while creating a new cluster
RUN apk add --no-cache --update openssh-keygen
RUN apk add --no-cache curl

RUN curl -LO "https://storage.googleapis.com/kubernetes-release/release/$(curl -s https://storage.googleapis.com/kubernetes-release/release/stable.txt)/bin/linux/amd64/kubectl"
RUN chmod +x ./kubectl
RUN mv ./kubectl /usr/local/bin/kubectl

RUN curl -LO https://github.com/kubernetes/kops/releases/download/$(curl -s https://api.github.com/repos/kubernetes/kops/releases/latest | grep tag_name | cut -d '"' -f 4)/kops-linux-amd64
RUN chmod +x kops-linux-amd64
RUN mv kops-linux-amd64 /usr/local/bin/kops

RUN curl -s https://api.github.com/repos/kubernetes-sigs/kustomize/releases | grep browser_download | grep linux | cut -d '"' -f 4 | grep /kustomize/$version.*amd64 | sort -r | head -1 | xargs curl -sL --output kustomize_linux_amd64.tar.gz
RUN tar xzf ./kustomize_linux_amd64.tar.gz
RUN mv kustomize /usr/local/bin/kustomize
RUN rm ./kustomize_linux_amd64.tar.gz