chore: dockerfile.example (#505)

* fix(build): include CA certificates in Docker image (#483)

Ensure the image contains trusted CA certificates so the app can establish
secure HTTPS connections to AWS services. Without them, TLS handshakes
fail with **x509: certificate signed by unknown authority**:

`failed to check if infra exists: operation error SQS: GetQueueUrl, exceeded maximum number of attempts, 3, https response error StatusCode: 0, RequestID: , request send failed, Post "https://sqs.eu-west-1.amazonaws.com/": tls: failed to verify certificate: x509: certificate signed by unknown authority`

* chore(build): Copy go mod files first to leverage Docker layer cachin… (#482)

* chore(build): Copy go mod files first to leverage Docker layer caching for dependencies

* chore(build): reorder WORKDIR command

* chore: rename to dockerfile.example

* chore: update dockerfile.example to include entrypoint.sh

* chore: comment

---------

Co-authored-by: Olivier Bazoud <[email protected]>

Author: alexluong

build/Dockerfile

@@ -0,0 +1,46 @@
+# ⚠️ IMPORTANT: This Dockerfile is for REFERENCE ONLY and is NOT production-ready.
+#
+# We do NOT recommend using this Dockerfile in production. Instead, use the official
+# hookdeck/outpost image from Docker Hub:
+#   docker pull hookdeck/outpost:latest
+#
+# The official image is optimized, regularly updated, and fully supported.
+#
+# This example is provided for educational purposes and as a starting point for
+# custom builds. If you need help with custom deployments, please create a
+# discussion at: https://github.com/hookdeck/outpost/discussions
+
+# Stage 0
+# Build the binaries
+FROM golang:1.23-alpine
+WORKDIR /app
+COPY go.mod go.sum ./
+RUN go mod download
+COPY . .
+
+# Build all binaries
+RUN go build -o ./bin/outpost ./cmd/outpost/main.go && \
+    go build -o ./bin/outpost-server ./cmd/outpost-server/main.go && \
+    go build -o ./bin/outpost-migrate-redis ./cmd/outpost-migrate-redis/main.go
+
+# Stage 1
+# Get busybox shell for entrypoint script
+FROM busybox:1.36-musl AS busybox
+
+# Stage 2
+# Copy binaries to a new image
+FROM gcr.io/distroless/base-debian12:nonroot
+
+# Copy statically linked shell from busybox for entrypoint script
+COPY --from=busybox /bin/sh /bin/sh
+
+# Copy all binaries
+COPY --from=0 /app/bin/outpost /usr/local/bin/outpost
+COPY --from=0 /app/bin/outpost-server /usr/local/bin/outpost-server
+COPY --from=0 /app/bin/outpost-migrate-redis /usr/local/bin/outpost-migrate-redis
+
+# Copy entrypoint script
+COPY --from=0 /app/build/entrypoint.sh /usr/local/bin/entrypoint.sh
+
+# Default entrypoint runs migrations and starts server
+ENTRYPOINT ["/bin/sh", "/usr/local/bin/entrypoint.sh"]