merge multiple installs into one

0.18/source/Dockerfile

@@ -6,20 +6,24 @@ COPY --from=lncm/berkeleydb:db-4.8.30.NC /opt /opt
 
 # Replace `http:` repositories with `https:` ones
 RUN sed -i 's/http\:\/\/dl-cdn.alpinelinux.org/https\:\/\/alpine.global.ssl.fastly.net/g' /etc/apk/repositories
-RUN apk --no-cache add autoconf
-RUN apk --no-cache add automake
-RUN apk --no-cache add boost-dev
-RUN apk --no-cache add build-base
-RUN apk --no-cache add chrpath
-RUN apk --no-cache add file
-RUN apk --no-cache add gnupg
-RUN apk --no-cache add libevent-dev
-RUN apk --no-cache add libressl
-RUN apk --no-cache add libressl-dev
-RUN apk --no-cache add libtool
-RUN apk --no-cache add linux-headers
-RUN apk --no-cache add protobuf-dev
-RUN apk --no-cache add zeromq-dev
+
+# install packages necessary to build Bitcoind
+RUN apk add --no-cache --update \
+    autoconf \
+    automake \
+    boost-dev \
+    build-base \
+    chrpath \
+    file \
+    gnupg \
+    libevent-dev \
+    libressl \
+    libressl-dev \
+    libtool \
+    linux-headers \
+    protobuf-dev \
+    zeromq-dev
+
 RUN set -ex \
   && for key in \
     90C8019E36C2E964 \
@@ -85,13 +89,15 @@ LABEL maintainer.0="nolim1t (@nolim1t)" \
 # TODO: Eliminating the two RUN lines below is necessary to cross-compile…
 # Replace `http:` repositories with `https:` ones
 RUN sed -i 's/http\:\/\/dl-cdn.alpinelinux.org/https\:\/\/alpine.global.ssl.fastly.net/g' /etc/apk/repositories
-RUN apk --no-cache add \
-  boost \
-  boost-program_options \
-  libevent \
-  libressl \
-  libzmq \
-  su-exec
+
+RUN apk --no-cache --update \
+    add \
+    boost \
+    boost-program_options \
+    libevent \
+    libressl \
+    libzmq \
+    su-exec
 
 ENV BITCOIN_VERSION=0.18.0
 ENV BITCOIN_PREFIX=/opt/bitcoin-${BITCOIN_VERSION}