Update and cleanup Dockerfiles

Dockerfile

@@ -1,13 +1,12 @@
 ARG EKSCTL_BUILD_IMAGE
 FROM $EKSCTL_BUILD_IMAGE AS build
 
-RUN apk add --update \
+RUN apk add --no-cache \
       py-pip \
       python \
       python-dev \
       && true
 
-RUN mkdir /out
 RUN mkdir -p /out/etc/apk && cp -r /etc/apk/* /out/etc/apk/
 RUN apk add --no-cache --initdb --root /out \
     alpine-baselayout \
@@ -35,7 +34,7 @@ RUN make lint && make test && make build \
 RUN go build ./vendor/github.com/kubernetes-sigs/aws-iam-authenticator/cmd/aws-iam-authenticator \
     && cp ./aws-iam-authenticator /out/usr/local/bin/aws-iam-authenticator
 
-RUN pip install --root=/out aws-mfa==0.0.12 awscli==1.15.40
+RUN pip install --root=/out aws-mfa==0.0.12 awscli==1.16.33
 
 WORKDIR /out
 

build/Dockerfile

@@ -1,13 +1,13 @@
-FROM golang:1.10.2-alpine3.7
+FROM golang:1.11-alpine3.8
 
-RUN apk add --update \
+RUN apk add --no-cache \
       curl \
       git \
       make \
       gcc \
       && true
 
-ENV DEP_VERSION v0.4.1
+ENV DEP_VERSION v0.5.0
 
 # Install dep to avoid vendoring all the things
 RUN curl --silent --location "https://github.com/golang/dep/releases/download/${DEP_VERSION}/dep-linux-amd64" --output /usr/local/bin/dep \
@@ -21,8 +21,6 @@ WORKDIR $EKSCTL_BUILD
 
 RUN dep ensure
 
-WORKDIR $EKSCTL_BUILD
-
 RUN ./install.sh
 
 WORKDIR $EKSCTL_BUILD/vendor/github.com/goreleaser/goreleaser