Split build-container-image into build-container-image-{debug,release}

This allows `run-in-container` to default to using the much faster
`build-container-image-debug`.

Dockerfile

@@ -15,14 +15,23 @@ WORKDIR /app
 
 COPY . /app
 
+ARG RELEASE_BUILD=true
+
 RUN --mount=type=cache,target=/cargo,sharing=locked \
 	--mount=type=cache,target=/target,sharing=locked \
-	cargo build --release
+	if [ "$RELEASE_BUILD" = "true" ]; then \
+		cargo build --release; \
+	else \
+		cargo build; \
+	fi
 
 # Move it out of the mounted cache, so we can copy it in the next stage.
 RUN --mount=type=cache,target=/target,sharing=locked \
-	cp /target/release/baibot /baibot
-
+	if [ "$RELEASE_BUILD" = "true" ]; then \
+		cp /target/release/baibot /baibot; \
+	else \
+		cp /target/debug/baibot /baibot; \
+	fi
 
 #######################################
 #                                     #

docs/installation.md

@@ -15,8 +15,16 @@
 
 We provide prebuilt container images for the `amd64` and `arm64` architectures, so **you don't necessarily need to build images yourself** and can jump to [Running in a container](#-running-in-a-container).
 
-If you nevertheless wish to build a container image yourself, you can do so by running `just build-container-image`.
-This will build and tag your container image as `localhost/baibot:latest`.
+If you nevertheless wish to build a container image yourself, you can do so by running:
+
+- (recommended) `just build-container-image-release` to build a release version of the container image
+
+- or `just build-container-image-debug` to build a debug version of the container image
+
+Debug images are faster to build but are larger in size.
+Release images are ~5x smaller in size, but are slower to build.
+
+Both of these commands will build and tag your container image as `localhost/baibot:latest`.
 
 
 ### 🐋 Running in a container

justfile

@@ -14,7 +14,7 @@ run-locally *extra_args: app-local-prepare
 	cargo run -- {{ extra_args }}
 
 # Builds and runs the bot in a container
-run-in-container *extra_args: app-container-prepare build-container-image
+run-in-container *extra_args: app-container-prepare build-container-image-debug
 	/usr/bin/env docker run \
 	-it \
 	--rm \
@@ -39,9 +39,16 @@ build-debug *extra_args:
 # Builds an optimized release binary (target/release/*)
 build-release *extra_args: (build-debug "--release")
 
-# Builds a container image
-build-container-image tag='latest':
+# Builds a container image (debug mode)
+build-container-image-debug tag='latest': (_build-container-image "false" tag)
+
+# Builds a container image (release mode)
+build-container-image-release tag='latest': (_build-container-image "true" tag)
+
+_build-container-image release_build tag:
 	/usr/bin/env docker build \
+	--build-arg RELEASE_BUILD={{ release_build }} \
+	-f {{ justfile_directory() }}/Dockerfile \
 	-t {{ container_image_name }}:{{ tag }} \
 	.