Update Dockerfile to reduce image size

Author: sagnik3788

build/Dockerfile

@@ -1,31 +1,46 @@
-FROM golang:1.14.2
-
-LABEL maintainer="LitmusChaos"
-
-RUN apt-get update && apt-get install -y git && \
-    apt-get install -y ssh && \
-    apt install ssh rsync
-
-ARG KUBECTL_VERSION=1.18.0
-
-#setup go envs
-ENV GO111MODULE=off
-ENV GOPATH=$HOME/go
-ENV PATH=$PATH:/usr/local/go/bin:$GOPATH/bin
-
-#Installing helm
-RUN wget https://get.helm.sh/helm-v3.4.0-linux-amd64.tar.gz && \ 
-    tar -zxvf helm-v3.4.0-linux-amd64.tar.gz && \
-    mv linux-amd64/helm /usr/local/bin/helm
-
-#Install kubectl
-ADD https://storage.googleapis.com/kubernetes-release/release/v${KUBECTL_VERSION}/bin/linux/amd64/kubectl /usr/local/bin/kubectl
-RUN chmod +x /usr/local/bin/kubectl
-
-#copying binaries
-COPY build/_output ./
-COPY litmus/helm-install.sh ./ 
-COPY build/experiment_entrypoint.sh ./
-
-#overwrite entrypoint with test binary
-ENTRYPOINT ["./all-experiments"]
+FROM golang:alpine AS builder
+
+# Set Go environment variables
+ENV GO111MODULE=off
+ENV GOPATH=/go
+ENV PATH=$PATH:/usr/local/go/bin:$GOPATH/bin
+
+# Install dependencies and cleanup
+RUN apk update && \
+    apk add --no-cache \
+        git \
+        wget \
+        tar
+
+# Install Helm
+RUN wget https://get.helm.sh/helm-v3.4.0-linux-amd64.tar.gz && \
+    tar -zxvf helm-v3.4.0-linux-amd64.tar.gz && \
+    mv linux-amd64/helm /usr/local/bin/helm && \
+    rm -rf helm-v3.4.0-linux-amd64.tar.gz linux-amd64
+
+# Install kubectl
+RUN wget https://storage.googleapis.com/kubernetes-release/release/v1.18.0/bin/linux/amd64/kubectl -O /usr/local/bin/kubectl && \
+    chmod +x /usr/local/bin/kubectl
+
+# Copy and build the binaries
+COPY build/_output /app/_output
+COPY litmus/helm-install.sh /app/
+COPY build/experiment_entrypoint.sh /app/
+
+FROM alpine:latest
+
+# Install runtime dependencies
+RUN apk update && \
+    apk add --no-cache \
+        openssh-client
+
+# Copy only the necessary files from the build stage
+COPY --from=builder /app /app
+COPY --from=builder /usr/local/bin/kubectl /usr/local/bin/kubectl
+COPY --from=builder /usr/local/bin/helm /usr/local/bin/helm
+
+# Set working directory
+WORKDIR /app
+
+# Override entrypoint with test binary
+ENTRYPOINT ["./all-experiments"]