Allow escaping $ in environment variable interpolation (#560)

* Add test for escaped dollar signs

* Check for 2663 and return it rather than an error in env parsing

* Consolidate the parEnv and envMapper functions

end_to_end_testing/course_files/03_test_env_var.yml

@@ -15,3 +15,9 @@ charts:
  comment-problem-detector:
  # This is a comment "${this_var_should_not_be_parsed}"
  - test-value
+ escape-values:
+ repository: fairwinds-incubator
+ chart: basic-demo
+ namespace: 03-infra
+ values:
+ non-used: "A string that needs a $$ in it"

pkg/course/course.go

@@ -625,21 +625,22 @@ func parseSecrets(courseData []byte) error {
 }
 
 func parseEnv(data string) (string, error) {
- dataWithEnv := os.Expand(data, envMapper)
+ dataWithEnv := os.Expand(data, func(key string) string {
+ if key == "$" {
+ return "$$"
+ }
+ if value, ok := os.LookupEnv(key); ok {
+ return value
+ }
+ color.Red("ERROR: environment variable %s is not set", key)
+ return "_ENV_NOT_SET_"
+ })
  if strings.Contains(dataWithEnv, "_ENV_NOT_SET_") {
  return data, fmt.Errorf("course has env variables that are not properly set")
  }
  return dataWithEnv, nil
 }
 
-func envMapper(key string) string {
- if value, ok := os.LookupEnv(key); ok {
- return value
- }
- color.Red("ERROR: environment variable %s is not set", key)
- return "_ENV_NOT_SET_"
-}
-
 func boolPtr(b bool) *bool {
  return &b
 }

pkg/course/course_test.go

@@ -15,6 +15,7 @@
 package course
 
 import (
+ "os"
  "testing"
 
  "github.com/stretchr/testify/assert"
@@ -221,3 +222,58 @@ func TestFileV2_populateDefaultRepository(t *testing.T) {
  })
  }
 }
+
+func Test_parseEnv(t *testing.T) {
+
+ tests := []struct {
+ name string
+ data string
+ want string
+ envMap map[string]string
+ wantErr bool
+ }{
+ {
+ name: "basic error check",
+ data: "$this-is-certainly-not-a-valid-env-var",
+ wantErr: true,
+ },
+ {
+ name: "basic test",
+ data: "$TEST_ENV_KEY",
+ want: "test-env-value",
+ envMap: map[string]string{
+ "TEST_ENV_KEY": "test-env-value",
+ },
+ wantErr: false,
+ },
+ {
+ name: "escaping test",
+ data: "$$TEST_ENV_KEY",
+ want: "$$TEST_ENV_KEY",
+ envMap: map[string]string{
+ "TEST_ENV_KEY": "test-env-value",
+ },
+ wantErr: false,
+ },
+ }
+ for _, tt := range tests {
+ t.Run(tt.name, func(t *testing.T) {
+ for k, v := range tt.envMap {
+ os.Setenv(k, v)
+ }
+
+ got, err := parseEnv(tt.data)
+ if tt.wantErr {
+ assert.Error(t, err)
+ } else {
+ assert.NoError(t, err)
+ assert.EqualValues(t, tt.want, got)
+ }
+ })
+ }
+}
+
+func Test_boolPtr(t *testing.T) {
+ testBool := true
+ assert.EqualValues(t, &testBool, boolPtr(testBool))
+}