From f80c5741dcd92237678cb06947ab57a6b2e96cac Mon Sep 17 00:00:00 2001
From: Yujun Zhang <zhangyujun@gmail.com>
Date: Fri, 31 Jan 2020 20:36:55 +0800
Subject: [PATCH] Allow loading file from http

---
 api/internal/target/kusttarget.go    | 20 ++++++++------------
 api/krusty/accumulation_test.go      |  4 ++--
 api/loader/fileloader.go             | 17 +++++++++++++++++
 examples/loadHttp.md                 | 25 +++++++++++++++++++++++++
 examples/loadHttp/kustomization.yaml | 15 +++++++++++++++
 5 files changed, 67 insertions(+), 14 deletions(-)
 create mode 100644 examples/loadHttp.md
 create mode 100644 examples/loadHttp/kustomization.yaml

diff --git a/api/internal/target/kusttarget.go b/api/internal/target/kusttarget.go
index 35a2b281d28..f5fb08fb98b 100644
--- a/api/internal/target/kusttarget.go
+++ b/api/internal/target/kusttarget.go
@@ -7,7 +7,6 @@ import (
 	"bytes"
 	"encoding/json"
 	"fmt"
-	"log"
 	"strings"
 
 	"github.com/pkg/errors"
@@ -302,18 +301,15 @@ func (kt *KustTarget) configureExternalTransformers() ([]resmap.Transformer, err
 func (kt *KustTarget) accumulateResources(
 	ra *accumulator.ResAccumulator, paths []string) error {
 	for _, path := range paths {
-		ldr, err := kt.ldr.New(path)
-		if err == nil {
-			err = kt.accumulateDirectory(ra, ldr)
-			if err != nil {
-				return err
+		// try loading resource as file then as base (directory or git repository)
+		if errF := kt.accumulateFile(ra, path); errF != nil {
+			ldr, errL := kt.ldr.New(path)
+			if errL != nil {
+				return fmt.Errorf("accumulateFile %q, loader.New %q", errF, errL)
 			}
-		} else {
-			err2 := kt.accumulateFile(ra, path)
-			if err2 != nil {
-				// Log ldr.New() error to highlight git failures.
-				log.Print(err.Error())
-				return err2
+			errD := kt.accumulateDirectory(ra, ldr)
+			if errD != nil {
+				return fmt.Errorf("accumulateFile %q, accumulateDirector: %q", errF, errD)
 			}
 		}
 	}
diff --git a/api/krusty/accumulation_test.go b/api/krusty/accumulation_test.go
index e0df8445652..491e52013bb 100644
--- a/api/krusty/accumulation_test.go
+++ b/api/krusty/accumulation_test.go
@@ -74,7 +74,7 @@ spec:
 	if err == nil {
 		t.Fatalf("expected an error")
 	}
-	if !IsMissingKustomizationFileError(err) {
+	if !strings.Contains(err.Error(), "accumulating resources") {
 		t.Fatalf("unexpected error: %q", err)
 	}
 }
@@ -89,7 +89,7 @@ resources:
 	if err == nil {
 		t.Fatalf("expected an error")
 	}
-	if !strings.Contains(err.Error(), "'/app/deployment.yaml' doesn't exist") {
+	if !strings.Contains(err.Error(), "accumulating resources") {
 		t.Fatalf("unexpected error: %q", err)
 	}
 }
diff --git a/api/loader/fileloader.go b/api/loader/fileloader.go
index 0822d0c8489..d7fddac94c4 100644
--- a/api/loader/fileloader.go
+++ b/api/loader/fileloader.go
@@ -5,7 +5,10 @@ package loader
 
 import (
 	"fmt"
+	"io/ioutil"
 	"log"
+	"net/http"
+	"net/url"
 	"path/filepath"
 	"strings"
 
@@ -293,6 +296,20 @@ func (fl *fileLoader) errIfRepoCycle(newRepoSpec *git.RepoSpec) error {
 // else an error.  Relative paths are taken relative
 // to the root.
 func (fl *fileLoader) Load(path string) ([]byte, error) {
+	if u, err := url.Parse(path); err == nil && strings.HasPrefix(u.Scheme, "http") {
+		client := &http.Client{}
+		resp, err := client.Get(path)
+		if err != nil {
+			return nil, err
+		}
+		defer resp.Body.Close()
+		body, err := ioutil.ReadAll(resp.Body)
+		if err != nil {
+			return nil, err
+		}
+		return body, nil
+	}
+
 	if !filepath.IsAbs(path) {
 		path = fl.root.Join(path)
 	}
diff --git a/examples/loadHttp.md b/examples/loadHttp.md
new file mode 100644
index 00000000000..fb1e78386a8
--- /dev/null
+++ b/examples/loadHttp.md
@@ -0,0 +1,25 @@
+# load file from http
+
+Resource and patch files could be loaded from http
+
+<!-- @loadHttp -->
+```sh
+DEMO_HOME=$(mktemp -d)
+
+cat <<EOF >$DEMO_HOME/kustomization.yaml
+resources:
+- https://raw.githubusercontent.com/kubernetes-sigs/kustomize/master/examples/helloWorld/configMap.yaml
+EOF
+```
+
+<!-- @loadHttp -->
+```sh
+test 1 == \
+  $(kustomize build $DEMO_HOME | grep "Good Morning!" | wc -l); \
+  echo $?
+```
+
+Kustomize will try loading resource as a file either from local or http. If it
+fails, try to load it as a directory or git repository.
+
+Http load applies to patches as well. See full example in [loadHttp](loadHttp/).
diff --git a/examples/loadHttp/kustomization.yaml b/examples/loadHttp/kustomization.yaml
new file mode 100644
index 00000000000..28e1b6ad42a
--- /dev/null
+++ b/examples/loadHttp/kustomization.yaml
@@ -0,0 +1,15 @@
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+resources:
+- https://raw.githubusercontent.com/kubernetes-sigs/kustomize/master/examples/wordpress/wordpress/deployment.yaml
+- https://github.com/knative/serving/releases/download/v0.12.0/serving.yaml # redirects to s3
+patches:
+- https://raw.githubusercontent.com/kubernetes-sigs/kustomize/master/examples/wordpress/patch.yaml
+patchesStrategicMerge:
+- |-
+  apiVersion: rbac.authorization.k8s.io/v1
+  kind: RoleBinding
+  metadata:
+    name: custom-metrics-auth-reader
+    namespace: kube-system
+  $patch: delete