feat: switch default container image from Ubuntu to Alpine

.github/workflows/lint_and_test.yml

@@ -129,10 +129,10 @@ jobs:
             ghcr.io/patrickhoefler/dockerfilegraph:latest \
             --version
 
-      - name: Get the version on Alpine
+      - name: Get the version on Ubuntu
         run: |
           docker run \
-            ghcr.io/patrickhoefler/dockerfilegraph:alpine \
+            ghcr.io/patrickhoefler/dockerfilegraph:ubuntu \
             --version
 
       - name: Run the Docker image with flags
@@ -147,14 +147,14 @@ jobs:
             --output png \
             --dpi 200
 
-      - name: Run the Alpine-based Docker image with flags
+      - name: Run the Ubuntu-based Docker image with flags
         run: |
           cd examples/dockerfiles
           docker run \
             --user "$(id -u):$(id -g)" \
             --workdir /workspace \
             --volume "$(pwd)":/workspace \
-            ghcr.io/patrickhoefler/dockerfilegraph:alpine \
+            ghcr.io/patrickhoefler/dockerfilegraph:ubuntu \
             --legend \
             --output png \
             --dpi 200

.gitignore

@@ -22,6 +22,6 @@ dockerfilegraph
 
 # dockerfilegraph
 Dockerfile.*
-!/Dockerfile.alpine
+!/Dockerfile.ubuntu
 !Dockerfile.golden.dot
 !examples/dockerfiles/Dockerfile.large

.goreleaser.yaml

@@ -23,15 +23,20 @@ dockers:
       - 'ghcr.io/patrickhoefler/dockerfilegraph:{{ .Major }}'
       - 'ghcr.io/patrickhoefler/dockerfilegraph:{{ .Major }}.{{ .Minor }}'
       - 'ghcr.io/patrickhoefler/dockerfilegraph:{{ .Major }}.{{ .Minor }}.{{ .Patch }}'
-
-  - dockerfile: Dockerfile.alpine
-    image_templates:
       - 'ghcr.io/patrickhoefler/dockerfilegraph:alpine'
       - 'ghcr.io/patrickhoefler/dockerfilegraph:latest-alpine'
       - 'ghcr.io/patrickhoefler/dockerfilegraph:{{ .Major }}-alpine'
       - 'ghcr.io/patrickhoefler/dockerfilegraph:{{ .Major }}.{{ .Minor }}-alpine'
       - 'ghcr.io/patrickhoefler/dockerfilegraph:{{ .Major }}.{{ .Minor }}.{{ .Patch }}-alpine'
 
+  - dockerfile: Dockerfile.ubuntu
+    image_templates:
+      - 'ghcr.io/patrickhoefler/dockerfilegraph:ubuntu'
+      - 'ghcr.io/patrickhoefler/dockerfilegraph:latest-ubuntu'
+      - 'ghcr.io/patrickhoefler/dockerfilegraph:{{ .Major }}-ubuntu'
+      - 'ghcr.io/patrickhoefler/dockerfilegraph:{{ .Major }}.{{ .Minor }}-ubuntu'
+      - 'ghcr.io/patrickhoefler/dockerfilegraph:{{ .Major }}.{{ .Minor }}.{{ .Patch }}-ubuntu'
+
 brews:
   - repository:
       owner: patrickhoefler

Dockerfile

@@ -1,23 +1,20 @@
 ### Release image
-FROM ubuntu:oracular-20250225@sha256:aadf9a3f5eda81295050d13dabe851b26a67597e424a908f25a63f589dfed48f
+FROM alpine:3.21.3@sha256:a8560b36e8b8210634f77d9f7f9efd7ffa463e380b75e2e74aff4511df3ef88c
 
 LABEL org.opencontainers.image.source="https://github.com/patrickhoefler/dockerfilegraph"
 
-# renovate: datasource=repology depName=ubuntu_24_04/fonts-dejavu versioning=loose
-ENV FONTS_DEJAVU_VERSION="2.37-8"
+# renovate: datasource=repology depName=alpine_3_21/font-dejavu versioning=loose
+ENV FONT_DEJAVU_VERSION="2.37-r5"
 
-# renovate: datasource=repology depName=ubuntu_24_04/graphviz versioning=loose
-ENV GRAPHVIZ_VERSION="2.42.4-2build2"
+# renovate: datasource=repology depName=alpine_3_21/graphviz versioning=loose
+ENV GRAPHVIZ_VERSION="12.2.0-r0"
 
-RUN \
-  apt-get update \
-  && apt-get install -y --no-install-recommends \
-  fonts-dejavu="${FONTS_DEJAVU_VERSION}" \
+RUN apk add --update --no-cache \
+  font-dejavu="${FONT_DEJAVU_VERSION}" \
   graphviz="${GRAPHVIZ_VERSION}" \
-  && rm -rf /var/lib/apt/lists/* \
   \
   # Add a non-root user
-  && useradd app
+  && adduser -D app
 
 # Run as non-root user
 USER app

Dockerfile.ubuntu

@@ -0,0 +1,29 @@
+### Release image
+FROM ubuntu:oracular-20250225@sha256:aadf9a3f5eda81295050d13dabe851b26a67597e424a908f25a63f589dfed48f
+
+LABEL org.opencontainers.image.source="https://github.com/patrickhoefler/dockerfilegraph"
+
+# renovate: datasource=repology depName=ubuntu_24_10/fonts-dejavu versioning=loose
+ENV FONTS_DEJAVU_VERSION="2.37-8"
+
+# renovate: datasource=repology depName=ubuntu_24_10/graphviz versioning=loose
+ENV GRAPHVIZ_VERSION="2.42.4-2build2"
+
+RUN \
+  apt-get update \
+  && apt-get install -y --no-install-recommends \
+  fonts-dejavu="${FONTS_DEJAVU_VERSION}" \
+  graphviz="${GRAPHVIZ_VERSION}" \
+  && rm -rf /var/lib/apt/lists/* \
+  \
+  # Add a non-root user
+  && useradd app
+
+# Run as non-root user
+USER app
+
+# This only works after running `make build-linux`
+# or when using goreleaser
+COPY dockerfilegraph /
+
+ENTRYPOINT ["/dockerfilegraph"]

Makefile

@@ -12,13 +12,13 @@ build: clean
 	go build $(FLAGS)
 
 build-docker-image-alpine: build-linux
-	docker build -t dockerfilegraph:alpine -f Dockerfile.alpine .
+	docker build -t dockerfilegraph:alpine -f Dockerfile .
 
 build-docker-image-ubuntu: build-linux
-	docker build -t dockerfilegraph:ubuntu -f Dockerfile .
+	docker build -t dockerfilegraph:ubuntu -f Dockerfile.ubuntu .
 
 build-linux: clean
-	GOOS=linux go build $(FLAGS)
+	CGO_ENABLED=0 GOOS=linux go build $(FLAGS)
 
 clean:
 	go clean

README.md

@@ -53,20 +53,20 @@ Run `dockerfilegraph` in your project directory to generate a `Dockerfile.pdf` w
 
 #### Docker
 
-- **Alpine-based** (Graphviz 12.2):
+- **Alpine-based** (Graphviz 12.2) - **Default**:
 
   ```shell
   docker run --rm --user "$(id -u):$(id -g)" \
     -v "$(pwd)":/workspace -w /workspace \
-    ghcr.io/patrickhoefler/dockerfilegraph:alpine
+    ghcr.io/patrickhoefler/dockerfilegraph
   ```
 
 - **Ubuntu-based** (Graphviz 2.42):
 
   ```shell
   docker run --rm --user "$(id -u):$(id -g)" \
     -v "$(pwd)":/workspace -w /workspace \
-    ghcr.io/patrickhoefler/dockerfilegraph
+    ghcr.io/patrickhoefler/dockerfilegraph:ubuntu
   ```
 
 #### Homebrew

internal/cmd/testdata/Dockerfile.golden.dot

@@ -1,5 +1,5 @@
 digraph G {
-	graph [bb="0,0,543,252",
+	graph [bb="0,0,541.25,252",
 		compound=true,
 		nodesep=1.00,
 		rankdir=LR,
@@ -10,63 +10,63 @@ digraph G {
 		fontcolor=grey20,
 		height=0.5,
 		label="ubuntu:l...887c2c7ac",
-		pos="86,234",
+		pos="85.625,234",
 		shape=box,
 		style="dashed,rounded",
-		width=2.3056];
+		width=2.2951];
 	stage_0	[height=0.5,
 		label=ubuntu,
-		pos="285.5,234",
+		pos="284.25,234",
 		shape=box,
 		style=rounded,
 		width=2];
-	external_image_0 -> stage_0	[pos="e,213.41,234 169.04,234 180.32,234 191.9,234 203.17,234"];
+	external_image_0 -> stage_0	[pos="e,212.06,234 168.59,234 179.19,234 190.05,234 200.66,234"];
 	stage_2	[fillcolor=grey90,
 		height=0.5,
 		label=release,
-		pos="471,126",
+		pos="469.25,126",
 		shape=box,
 		style="filled,rounded",
 		width=2];
 	stage_0 -> stage_2	[arrowhead=empty,
-		pos="e,439.19,144.14 317.21,215.92 348.31,197.62 396.52,169.25 430.45,149.28",
+		pos="e,437.05,144.41 316.29,215.68 346.92,197.6 393.91,169.87 427.52,150.04",
 		style=dashed];
 	external_image_1	[color=grey20,
 		fontcolor=grey20,
 		height=0.5,
 		label="golang:1...b738433da",
-		pos="86,126",
+		pos="85.625,126",
 		shape=box,
 		style="dashed,rounded",
-		width=2.3889];
+		width=2.3785];
 	stage_1	[height=0.5,
 		label="build-tool-depend...",
-		pos="285.5,126",
+		pos="284.25,126",
 		shape=box,
 		style=rounded,
-		width=2.1528];
-	external_image_1 -> stage_1	[pos="e,207.99,126 172.19,126 180.65,126 189.25,126 197.73,126"];
+		width=2.1389];
+	external_image_1 -> stage_1	[pos="e,206.99,126 171.72,126 179.6,126 187.6,126 195.5,126"];
 	stage_1 -> stage_2	[arrowhead=empty,
-		pos="e,398.82,126 363.26,126 371.64,126 380.19,126 388.62,126",
+		pos="e,396.78,126 361.53,126 369.37,126 377.37,126 385.28,126",
 		style=dashed];
 	external_image_2	[color=grey20,
 		fontcolor=grey20,
 		height=0.5,
 		label=buildcache,
-		pos="86,18",
+		pos="85.625,18",
 		shape=box,
 		style="dashed,rounded",
 		width=2];
 	external_image_2 -> stage_1	[arrowhead=ediamond,
-		pos="e,251.34,107.86 120.06,36.077 153.1,54.144 204.09,82.03 240.53,101.96",
+		pos="e,249.73,107.59 119.98,36.321 152.61,54.241 202.51,81.651 238.55,101.45",
 		style=dotted];
 	external_image_3	[color=grey20,
 		fontcolor=grey20,
 		height=0.5,
 		label=scratch,
-		pos="285.5,18",
+		pos="284.25,18",
 		shape=box,
 		style="dashed,rounded",
 		width=2];
-	external_image_3 -> stage_2	[pos="e,439.19,107.86 317.21,36.077 348.31,54.378 396.52,82.753 430.45,102.72"];
+	external_image_3 -> stage_2	[pos="e,437.05,107.59 316.29,36.321 346.92,54.396 393.91,82.126 427.52,101.96"];
 }