Fix unsigned repository issue of GCP SDK (close #154)

k8s-dataflow/Dockerfile

@@ -4,13 +4,12 @@ LABEL MAINTAINER="Snowplow Analytics Ltd. <[email protected]>"
 SHELL ["/bin/bash", "-o", "pipefail", "-c"]
 
 RUN \
-  mkdir -p /var/lib/apt/lists/partial &&\
-  echo "deb [signed-by=/usr/share/keyrings/cloud.google.gpg] http://packages.cloud.google.com/apt cloud-sdk main" | tee -a /etc/apt/sources.list.d/google-cloud-sdk.list &&\
   apt-get update &&\
-  apt-get install -y --no-install-recommends apt-transport-https=1.4.10 ca-certificates=20200601~deb9u1 wget=1.18-5+deb9u3 gnupg=2.1.18-8~deb9u4 &&\
-  wget -O - http://packages.cloud.google.com/apt/doc/apt-key.gpg | apt-key --keyring /usr/share/keyrings/cloud.google.gpg add - &&\
+  echo "deb [signed-by=/usr/share/keyrings/cloud.google.gpg] https://packages.cloud.google.com/apt cloud-sdk main" | tee -a /etc/apt/sources.list.d/google-cloud-sdk.list &&\
+  apt-get install -y --no-install-recommends apt-transport-https=1.8.2.1 ca-certificates=20200601~deb10u1 gnupg=2.2.12-1+deb10u1 curl=7.64.0-4+deb10u1 &&\
+  curl https://packages.cloud.google.com/apt/doc/apt-key.gpg | apt-key --keyring /usr/share/keyrings/cloud.google.gpg add - &&\
   apt-get update &&\
-  apt-get install -y --no-install-recommends python=2.7.13-2 google-cloud-sdk=302.0.0-0 &&\
+  apt-get install -y --no-install-recommends google-cloud-sdk=316.0.0-0 &&\
   apt-get clean &&\
   rm -rf /var/lib/apt/lists/* &&\
   apt-get purge -y --auto-remove gnupg