dep: Upgrade kubectl from v1.20.2 to v1.20.5.

Dockerfile

@@ -16,12 +16,11 @@ FROM alpine:latest
 
 USER root
 
-ENV KUBECTL_VERSION v1.20.2
 COPY --from=gotty-build /gotty /usr/bin/
 RUN ARCH=$(uname -m) && case $ARCH in aarch64) ARCH="arm64";; x86_64) ARCH="amd64";; esac && echo "ARCH: " $ARCH && \
     echo > /etc/apk/repositories && echo -e "https://dl-cdn.alpinelinux.org/alpine/latest-stable/main\nhttps://dl-cdn.alpinelinux.org/alpine/latest-stable/community" >> /etc/apk/repositories && \
     apk add --update --no-cache bash bash-completion curl git wget openssl iputils busybox-extras vim ncurses && sed -i "s/nobody:\//nobody:\/nonexistent/g" /etc/passwd && \
-    curl -sLf https://storage.googleapis.com/kubernetes-release/release/${KUBECTL_VERSION}/bin/linux/${ARCH}/kubectl > /usr/bin/kubectl && chmod +x /usr/bin/kubectl && \
+    curl -sLf https://storage.googleapis.com/kubernetes-release/release/v1.20.5/bin/linux/${ARCH}/kubectl > /usr/bin/kubectl && chmod +x /usr/bin/kubectl && \
     git clone --branch v0.8.0 https://github.com/ahmetb/kubectx /opt/kubectx && chmod -R 755 /opt/kubectx && ln -s /opt/kubectx/kubectx /usr/local/bin/kubectx && ln -s /opt/kubectx/kubens /usr/local/bin/kubens && \
     git clone --branch master --depth 1 https://github.com/ahmetb/kubectl-aliases /opt/kubectl-aliases && chmod -R 755 /opt/kubectl-aliases && \
     git clone --branch 0.21.0 --depth 1 https://github.com/junegunn/fzf /opt/fzf && chmod -R 755 /opt/fzf && /opt/fzf/install && ln -s /opt/fzf/bin/fzf /usr/local/bin/fzf && \