build in two steps

.woodpecker.yml

@@ -2,7 +2,7 @@ pipeline:
   publish:
     image: plugins/docker
     registry: registry.nulo.in
-    repo: registry.nulo.in/sutty/CHANGEME
+    repo: registry.nulo.in/sutty/redis
     tags:
     - ${ALPINE_VERSION}
     - latest

Dockerfile

@@ -1,12 +1,10 @@
 ARG ALPINE_VERSION=3.13.6
 ARG BASE_IMAGE=sutty/monit
-FROM ${BASE_IMAGE}:${ALPINE_VERSION}
+FROM ${BASE_IMAGE}:${ALPINE_VERSION} AS build
 MAINTAINER "f <f@sutty.nl>"
 
 RUN apk add --no-cache redis
 
-COPY ./monit.conf /etc/monit.d/redis.conf
-
 RUN sed -re "/^bind /d" -i /etc/redis.conf
 RUN sed -re "/^protected-mode /d" -i /etc/redis.conf
 RUN sed -re "/^logfile /d" -i /etc/redis.conf
@@ -18,5 +16,15 @@ RUN echo "protected-mode no" >> /etc/redis.conf
 RUN echo "maxmemory-policy allkeys-lfu" >> /etc/redis.conf
 RUN echo "maxmemory 100mb" >> /etc/redis.conf
 
+ARG ALPINE_VERSION=3.13.6
+ARG BASE_IMAGE=sutty/monit
+FROM ${BASE_IMAGE}:${ALPINE_VERSION}
+MAINTAINER "f <f@sutty.nl>"
+
+RUN apk add --no-cache redis
+
+COPY --from=build /etc/redis.conf /etc/redis.conf
+COPY ./monit.conf /etc/monit.d/redis.conf
+
 EXPOSE 6379
 VOLUME "/var/lib/redis"