RED-46: Stop using our node base image

Our base image doesn't do much. Import what it does into the local Dockerfile

Dockerfile

@@ -1,5 +1,15 @@
-# govukpay/nodejs:alpine-3.8.1
-FROM govukpay/nodejs@sha256:a3ae1b0b3ab5e7cdefe0787b97b1047cdc5e0c5166fb677e3cefac538bc99f86
+# alpine:3.8
+FROM alpine@sha256:ea47a59a33f41270c02c8c7764e581787cf5b734ab10d27e876e62369a864459
+
+### Needed to run appmetrics and pact-mock-service
+ADD sgerrand.rsa.pub /etc/apk/keys/sgerrand.rsa.pub
+RUN ["apk", "--no-cache", "add", "ca-certificates"]
+RUN wget https://github.com/sgerrand/alpine-pkg-glibc/releases/download/2.28-r0/glibc-2.28-r0.apk && apk add --no-cache glibc-2.28-r0.apk && rm -f glibc-2.28-r0.apk
+###
+
+RUN ["apk", "--no-cache", "upgrade"]
+
+RUN ["apk", "add", "--no-cache", "nodejs", "npm"]
 
 ADD package.json /tmp/package.json
 ADD package-lock.json /tmp/package-lock.json
@@ -11,6 +21,6 @@ EXPOSE 9000
 WORKDIR /app
 ADD . /app
 ENV LD_LIBRARY_PATH /app/node_modules/appmetrics
-RUN ln -s /tmp/node_modules /app/node_modules
+RUN ["ln", "-s", "/tmp/node_modules", "/app/node_modules"]
 
 CMD npm start

sgerrand.rsa.pub

@@ -0,0 +1,9 @@
+-----BEGIN PUBLIC KEY-----
+MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEApZ2u1KJKUu/fW4A25y9m
+y70AGEa/J3Wi5ibNVGNn1gT1r0VfgeWd0pUybS4UmcHdiNzxJPgoWQhV2SSW1JYu
+tOqKZF5QSN6X937PTUpNBjUvLtTQ1ve1fp39uf/lEXPpFpOPL88LKnDBgbh7wkCp
+m2KzLVGChf83MS0ShL6G9EQIAUxLm99VpgRjwqTQ/KfzGtpke1wqws4au0Ab4qPY
+KXvMLSPLUp7cfulWvhmZSegr5AdhNw5KNizPqCJT8ZrGvgHypXyiFvvAH5YRtSsc
+Zvo9GI2e2MaZyo9/lvb+LbLEJZKEQckqRj4P26gmASrZEPStwc+yqy1ShHLA0j6m
+1QIDAQAB
+-----END PUBLIC KEY-----