From 16a1041d2e45c76bee11c43eb5cfa761089d22a5 Mon Sep 17 00:00:00 2001
From: Chris Goller <goller@gmail.com>
Date: Tue, 19 Dec 2017 15:06:24 -0600
Subject: [PATCH] Add env var golang templates to filestore rendering
---
filestore/dashboards.go | 3 +-
filestore/environ.go | 24 ++++++++++++++
filestore/environ_test.go | 29 +++++++++++++++++
filestore/templates.go | 28 ++++++++++++++++
filestore/templates_test.go | 64 +++++++++++++++++++++++++++++++++++++
5 files changed, 147 insertions(+), 1 deletion(-)
create mode 100644 filestore/environ.go
create mode 100644 filestore/environ_test.go
create mode 100644 filestore/templates.go
create mode 100644 filestore/templates_test.go
diff --git a/filestore/dashboards.go b/filestore/dashboards.go
index 6a73a1d11..9b8fc6578 100644
--- a/filestore/dashboards.go
+++ b/filestore/dashboards.go
@@ -47,10 +47,11 @@ func dashboardFile(dir string, dashboard chronograf.Dashboard) string {
}
func load(name string, resource interface{}) error {
- octets, err := ioutil.ReadFile(name)
+ octets, err := templatedFromEnv(name)
if err != nil {
return fmt.Errorf("resource %s not found", name)
}
+
return json.Unmarshal(octets, resource)
}
diff --git a/filestore/environ.go b/filestore/environ.go
new file mode 100644
index 000000000..091e179e8
--- /dev/null
+++ b/filestore/environ.go
@@ -0,0 +1,24 @@
+package filestore
+
+import (
+ "os"
+ "strings"
+)
+
+var env map[string]string
+
+// environ returns a map of all environment variables in the running process
+func environ() map[string]string {
+ if env == nil {
+ env = make(map[string]string)
+ envVars := os.Environ()
+ for _, envVar := range envVars {
+ kv := strings.SplitN(envVar, "=", 2)
+ if len(kv) != 2 {
+ continue
+ }
+ env[kv[0]] = kv[1]
+ }
+ }
+ return env
+}
diff --git a/filestore/environ_test.go b/filestore/environ_test.go
new file mode 100644
index 000000000..689484806
--- /dev/null
+++ b/filestore/environ_test.go
@@ -0,0 +1,29 @@
+package filestore
+
+import (
+ "os"
+ "testing"
+)
+
+func Test_environ(t *testing.T) {
+ tests := []struct {
+ name string
+ key string
+ value string
+ }{
+ {
+ name: "environment variable is returned",
+ key: "CHRONOGRAF_TEST_ENVIRON",
+ value: "howdy",
+ },
+ }
+ for _, tt := range tests {
+ t.Run(tt.name, func(t *testing.T) {
+ os.Setenv(tt.key, tt.value)
+ got := environ()
+ if v, ok := got[tt.key]; !ok || v != tt.value {
+ t.Errorf("environ() = %v, want %v", v, tt.value)
+ }
+ })
+ }
+}
diff --git a/filestore/templates.go b/filestore/templates.go
new file mode 100644
index 000000000..fc0e1ffc4
--- /dev/null
+++ b/filestore/templates.go
@@ -0,0 +1,28 @@
+package filestore
+
+import (
+ "bytes"
+ "html/template"
+)
+
+// templated returns all files templated using data
+func templated(data interface{}, filenames ...string) ([]byte, error) {
+ t, err := template.ParseFiles(filenames...)
+ if err != nil {
+ return nil, err
+ }
+ var b bytes.Buffer
+ // If a key in the file exists but is not in the data we
+ // immediately fail with a missing key error
+ err = t.Option("missingkey=error").Execute(&b, data)
+ if err != nil {
+ return nil, err
+ }
+
+ return b.Bytes(), nil
+}
+
+// templatedFromEnv returns all files templated against environment variables
+func templatedFromEnv(filenames ...string) ([]byte, error) {
+ return templated(environ(), filenames...)
+}
diff --git a/filestore/templates_test.go b/filestore/templates_test.go
new file mode 100644
index 000000000..5d5b82f5d
--- /dev/null
+++ b/filestore/templates_test.go
@@ -0,0 +1,64 @@
+package filestore
+
+import (
+ "io/ioutil"
+ "os"
+ "reflect"
+ "testing"
+)
+
+func Test_templated(t *testing.T) {
+ tests := []struct {
+ name string
+ content []string
+ data interface{}
+ want []byte
+ wantErr bool
+ }{
+ {
+ name: "files with templates are rendered correctly",
+ content: []string{
+ "{{ .MYVAR }}",
+ },
+ data: map[string]string{
+ "MYVAR": "howdy",
+ },
+ want: []byte("howdy"),
+ },
+ {
+ name: "missing key gives an error",
+ content: []string{
+ "{{ .MYVAR }}",
+ },
+ wantErr: true,
+ },
+ {
+ name: "no files make me an error!",
+ wantErr: true,
+ },
+ }
+ for _, tt := range tests {
+ t.Run(tt.name, func(t *testing.T) {
+ filenames := make([]string, len(tt.content))
+ for i, c := range tt.content {
+ f, err := ioutil.TempFile("", "")
+ if err != nil {
+ t.Fatal(err)
+ }
+ if _, err := f.Write([]byte(c)); err != nil {
+ t.Fatal(err)
+ }
+ filenames[i] = f.Name()
+ defer os.Remove(f.Name())
+ }
+ got, err := templated(tt.data, filenames...)
+ if (err != nil) != tt.wantErr {
+ t.Errorf("templated() error = %v, wantErr %v", err, tt.wantErr)
+ return
+ }
+ if !reflect.DeepEqual(got, tt.want) {
+ t.Errorf("templated() = %v, want %v", got, tt.want)
+ }
+ })
+ }
+}