From 5a890369a0ae9b11ce4c4a5043700b8fe41b2a00 Mon Sep 17 00:00:00 2001
From: David Gageot <david@gageot.net>
Date: Sat, 5 Oct 2019 12:01:28 +0200
Subject: [PATCH] Add support for Cloud Native Buildpacks pack CLI

Signed-off-by: David Gageot <david@gageot.net>
---
 pack/Dockerfile              |  7 +++++++
 pack/README.md               | 19 +++++++++++++++++++
 pack/cloudbuild.yaml         | 11 +++++++++++
 pack/example/cloudbuild.yaml | 10 ++++++++++
 pack/example/go.mod          |  3 +++
 pack/example/main.go         | 18 ++++++++++++++++++
 6 files changed, 68 insertions(+)
 create mode 100644 pack/Dockerfile
 create mode 100644 pack/README.md
 create mode 100644 pack/cloudbuild.yaml
 create mode 100644 pack/example/cloudbuild.yaml
 create mode 100644 pack/example/go.mod
 create mode 100644 pack/example/main.go

diff --git a/pack/Dockerfile b/pack/Dockerfile
new file mode 100644
index 000000000..c88308129
--- /dev/null
+++ b/pack/Dockerfile
@@ -0,0 +1,7 @@
+FROM busybox
+ENV PACK_VERSION=v0.4.1
+RUN wget -O- https://github.com/buildpack/pack/releases/download/${PACK_VERSION}/pack-${PACK_VERSION}-linux.tgz | tar zx
+
+FROM gcr.io/distroless/base
+ENTRYPOINT ["/pack"]
+COPY --from=0 /pack /
diff --git a/pack/README.md b/pack/README.md
new file mode 100644
index 000000000..ac7b00391
--- /dev/null
+++ b/pack/README.md
@@ -0,0 +1,19 @@
+# Pack
+
+[pack](https://github.com/buildpack/pack) is the CLI for building apps using [Cloud Native Buildpacks](https://buildpacks.io).
+
+This build step invokes `pack` commands in [Google Cloud Build](cloud.google.com/cloud-build/).
+
+Arguments passed to this builder will be passed to `pack` directly, allowing
+callers to run [any pack
+command](https://buildpacks.io/docs/using-pack/).
+
+## Usage:
+
+To build a Docker image from sources:
+
+```
+steps:
+- name: gcr.io/$PROJECT_ID/pack
+  args: ["build", "--builder", "heroku/buildpacks:18", "gcr.io/$PROJECT_ID/sample:tag"]
+```
diff --git a/pack/cloudbuild.yaml b/pack/cloudbuild.yaml
new file mode 100644
index 000000000..026998971
--- /dev/null
+++ b/pack/cloudbuild.yaml
@@ -0,0 +1,11 @@
+# In this directory, run the following command to build this builder.
+# $ gcloud builds submit . --config=cloudbuild.yaml
+
+steps:
+- name: 'gcr.io/cloud-builders/docker'
+  args: ['build', '--tag=gcr.io/${PROJECT_ID}/pack', '.']
+- name: 'gcr.io/${PROJECT_ID}/pack'
+  args: ['--help']
+
+images: ['gcr.io/${PROJECT_ID}/pack']
+tags: ['cloud-builders-community']
diff --git a/pack/example/cloudbuild.yaml b/pack/example/cloudbuild.yaml
new file mode 100644
index 000000000..98874fef1
--- /dev/null
+++ b/pack/example/cloudbuild.yaml
@@ -0,0 +1,10 @@
+steps:
+- name: 'gcr.io/$PROJECT_ID/pack'
+  args:
+    - build
+    - --builder
+    - heroku/buildpacks:18
+    - gcr.io/$PROJECT_ID/pack-sample
+
+images:
+  - gcr.io/$PROJECT_ID/pack-sample
diff --git a/pack/example/go.mod b/pack/example/go.mod
new file mode 100644
index 000000000..3f0fc6e12
--- /dev/null
+++ b/pack/example/go.mod
@@ -0,0 +1,3 @@
+module github.com/GoogleCloudPlatform/cloud-builders-community/pack/sample
+
+go 1.13
diff --git a/pack/example/main.go b/pack/example/main.go
new file mode 100644
index 000000000..5e666f89d
--- /dev/null
+++ b/pack/example/main.go
@@ -0,0 +1,18 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"net/http"
+)
+
+func main() {
+	http.HandleFunc("/", hello)
+
+	log.Println("Listening on port 8080")
+	http.ListenAndServe(":8080", nil)
+}
+
+func hello(w http.ResponseWriter, r *http.Request) {
+	fmt.Fprintf(w, "Hello, World!")
+}