release.sh, Dockerfile: always --pull, use alpine:latest, fix tagging

Signed-off-by: Thilo Fromm <thilo.alexander@gmail.com>

Dockerfile

@@ -1,5 +1,5 @@
 # First, build the metrics exporter and the "prips" (print ip ranges) tool.
-FROM alpine AS builder
+FROM alpine:latest AS builder
 ARG postfix_exporter_version=0.3.0
 ARG fail2ban_exporter_version=0.9.0
 ARG prips_version=1.2.0
@@ -37,7 +37,7 @@ RUN cd "/prips-$prips_version" \
     && mv prips /
 
 
-FROM alpine
+FROM alpine:latest
 
 COPY --from=builder /postfix_exporter /fail2ban-prometheus-exporter /prips /
 RUN apk update \

release.sh

@@ -47,8 +47,8 @@ if [ -n "${untracked}" ] ; then
 fi
 
 yell "Building the container image"
-docker build -t "${container}:${version}" .
-docker tag "${container}:latest" "${container}:${version}"
+docker build --pull -t "${container}:${version}" .
+docker tag "${container}:${version}" "${container}:latest"
 
 yell "Creating the release tarball"
 echo "${version}" >VERSION