use COPY instead of ADD, install pkgs then build
- using COPY instead of ADD, since working with local paths, and
not extracting archived data
- installing packages before building application binary improves caching,
and avoids installing packages every time the application code changes
# Build the go application into a binary
FROM golang:alpine as builder
+RUN apk --update add ca-certificates
WORKDIR /app
-ADD . ./
+COPY . ./
RUN CGO_ENABLED=0 GOOS=linux go build -mod vendor -a -installsuffix cgo -o gatus .
-RUN apk --update add ca-certificates
# Run Tests inside docker image if you don't have a configured go environment
#RUN apk update && apk add --virtual build-dependencies build-base gcc
