example docker file

build with:
     docker build -t intercert .

run with
    docker run -p 6300 intercert serve --agree --dns-provider=azure

Dockerfile

@@ -0,0 +1,59 @@
+# Accept the Go version for the image to be set as a build argument.
+ARG GO_VERSION=1.12
+
+ARG INTERCERT_VERSION="DEV-SNAPSHOT"
+
+# First stage: build the executable.
+FROM golang:${GO_VERSION}-alpine AS builder
+
+# Create the user and group files that will be used in the running container to
+# run the process as an unprivileged user.
+RUN mkdir /user && \
+    echo 'nobody:x:65534:65534:nobody:/:' > /user/passwd && \
+    echo 'nobody:x:65534:' > /user/group
+
+# Install the Certificate-Authority certificates for the app to be able to make
+# calls to HTTPS endpoints.
+# Git is required for fetching the dependencies.
+RUN apk add --no-cache ca-certificates git
+
+# Set the working directory outside $GOPATH to enable the support for modules.
+WORKDIR /src
+
+# Fetch dependencies first; they are less susceptible to change on every build
+# and will therefore be cached for speeding up the next build
+COPY ./go.mod ./go.sum ./
+RUN go mod download
+
+# Import the code from the context.
+COPY ./ ./ 
+
+# Build the executable to `/app`. Mark the build as statically linked.
+RUN CGO_ENABLED=0 go build -ldflags \
+    "-s -w -X main.Version=DEV-SNAPSHOT -X main.Commit=$(`echo git rev-parse --short HEAD`)" -o /app .
+
+# Final stage: the running container.
+FROM scratch AS final
+
+# Import the user and group files from the first stage.
+COPY --from=builder /user/group /user/passwd /etc/
+
+# Import the Certificate-Authority certificates for enabling HTTPS.
+COPY --from=builder /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/
+
+# Import the compiled executable from the first stage.
+COPY --from=builder /app /app
+
+# Declare the port on which the server will be exposed.
+# As we're going to run the executable as an unprivileged user, we can't bind
+# to ports below 1024.
+EXPOSE 6300
+
+VOLUME /server-data
+VOLUME /.intercert
+
+# Perform any further action as an unprivileged user.
+USER nobody:nobody
+
+# Run the compiled binary.
+ENTRYPOINT ["/app"]

cmd/root.go

@@ -1,6 +1,7 @@
 package cmd
 
 import (
+	"errors"
 	"fmt"
 	"runtime"
 
@@ -39,7 +40,8 @@ func initConfig() {
 
 	// Try to read config
 	if err := viper.ReadInConfig(); err != nil {
-		PrintErrorAndExit(err)
+		errMsg := fmt.Sprintf("Failed to read configuration: %v", err)
+		PrintErrorAndExit(errors.New(errMsg))
 	}
 }