Merge pull request #481 from hairyhenderson/envfile-support-479

Adding support for .env files

data/data.go

@@ -7,6 +7,8 @@ import (
 	"reflect"
 	"strings"
 
+	"github.com/joho/godotenv"
+
 	"github.com/Shopify/ejson"
 	ejsonJson "github.com/Shopify/ejson/json"
 	"github.com/hairyhenderson/gomplate/env"
@@ -100,6 +102,11 @@ func TOML(in string) (interface{}, error) {
 	return unmarshalObj(obj, in, toml.Unmarshal)
 }
 
+// dotEnv - Unmarshal a dotenv file
+func dotEnv(in string) (interface{}, error) {
+	return godotenv.Unmarshal(in)
+}
+
 func parseCSV(args ...string) ([][]string, []string, error) {
 	in, delim, hdr := csvParseArgs(args...)
 	c := csv.NewReader(strings.NewReader(in))

data/data_test.go

@@ -460,3 +460,25 @@ func TestDecryptEJSON(t *testing.T) {
 	assert.NoError(t, err)
 	assert.EqualValues(t, expected, actual)
 }
+
+func TestDotEnv(t *testing.T) {
+	in := `FOO=a regular unquoted value
+export BAR=another value, exports are ignored
+
+# comments are totally ignored, as are blank lines
+FOO.BAR = "values can be double-quoted, and shell\nescapes are supported"
+
+BAZ = "variable expansion: ${FOO}"
+QUX='single quotes ignore $variables'
+`
+	expected := map[string]string{
+		"FOO":     "a regular unquoted value",
+		"BAR":     "another value, exports are ignored",
+		"FOO.BAR": "values can be double-quoted, and shell\nescapes are supported",
+		"BAZ":     "variable expansion: a regular unquoted value",
+		"QUX":     "single quotes ignore $variables",
+	}
+	out, err := dotEnv(in)
+	assert.NoError(t, err)
+	assert.EqualValues(t, expected, out)
+}

data/datasource.go

@@ -36,6 +36,7 @@ func init() {
 	regExtension(".yaml", yamlMimetype)
 	regExtension(".csv", csvMimetype)
 	regExtension(".toml", tomlMimetype)
+	regExtension(".env", envMimetype)
 }
 
 // registerReaders registers the source-reader functions
@@ -338,6 +339,8 @@ func parseData(mimeType, s string) (out interface{}, err error) {
 		out, err = CSV(s)
 	case tomlMimetype:
 		out, err = TOML(s)
+	case envMimetype:
+		out, err = dotEnv(s)
 	case textMimetype:
 		out = s
 	default:

data/mimetypes.go

@@ -7,4 +7,5 @@ const (
 	jsonArrayMimetype = "application/array+json"
 	tomlMimetype      = "application/toml"
 	yamlMimetype      = "application/yaml"
+	envMimetype       = "application/x-env"
 )

docs/content/datasources.md

@@ -100,12 +100,13 @@ These are the supported types:
 
 | Format | MIME Type | Extension(s) | Notes |
 |--------|-----------|-------|------|
-| CSV | `text/csv` | | Uses the [`data.CSV`][] function to present the file as a 2-dimensional row-first string array |
-| JSON | `application/json` | | [JSON][] _objects_ are assumed, and arrays or other values are not parsed with this type. Uses the [`data.JSON`][] function for parsing. [EJSON][] (encrypted JSON) is supported and will be decrypted. |
+| CSV | `text/csv` | `.csv` | Uses the [`data.CSV`][] function to present the file as a 2-dimensional row-first string array |
+| JSON | `application/json` | `.json` | [JSON][] _objects_ are assumed, and arrays or other values are not parsed with this type. Uses the [`data.JSON`][] function for parsing. [EJSON][] (encrypted JSON) is supported and will be decrypted. |
 | JSON Array | `application/array+json` | | A special type for parsing datasources containing just JSON arrays. Uses the [`data.JSONArray`][] function for parsing |
 | Plain Text | `text/plain` | | Unstructured, and as such only intended for use with the [`include`][] function |
-| TOML | `application/toml` | | Parses [TOML][] with the [`data.TOML`][] function |
-| YAML | `application/yaml` | | Parses [YAML][] with the [`data.YAML`][] function |
+| TOML | `application/toml` | `.toml` | Parses [TOML][] with the [`data.TOML`][] function |
+| YAML | `application/yaml` | `.yml`, `.yaml` | Parses [YAML][] with the [`data.YAML`][] function |
+| [.env](#the-env-file-format) | `application/x-env` | `.env` | Basically just a file of `key=value` pairs separated by newlines, usually intended for sourcing into a shell. Common in [Docker Compose](https://docs.docker.com/compose/env-file/), [Ruby](https://github.com/bkeepers/dotenv), and [Node.js](https://github.com/motdotla/dotenv) applications. See [below](#the-env-file-format) for more information. |
 
 ### Overriding MIME Types
 
@@ -119,6 +120,28 @@ $ gomplate -d data=file:///tmp/data.txt?type=application/json -i '{{ (ds "data")
 bar
 ```
 
+### The `.env` file format
+
+Many applications and frameworks support the use of a ".env" file for providing environment variables. It can also be considerd a simple key/value file format, and as such can be used as a datasource in gomplate.
+
+To [override](#overriding-mime-types), use the unregistered `application/x-env` MIME type.
+
+Here's a sample explaining the syntax:
+
+```bash
+FOO=a regular unquoted value
+export BAR=another value, exports are ignored
+
+# comments are totally ignored, as are blank lines
+FOO.BAR = "values can be double-quoted, and\tshell\nescapes are supported"
+
+BAZ="variable expansion: ${FOO}"
+QUX='single quotes ignore $variables and newlines'
+```
+
+The [`github.com/joho/godotenv`](https://github.com/joho/godotenv) package is used for parsing - see the full details there.
+
+
 ## Using `aws+smp` datasources
 
 The `aws+smp://` scheme can be used to retrieve data from the [AWS Systems Manager](https://aws.amazon.com/systems-manager/) (née AWS EC2 Simple  Systems Manager) [Parameter Store](https://aws.amazon.com/systems-manager/features/#Parameter_Store). This hierarchically organized key/value store allows you to store text, lists or encrypted secrets for easy retrieval by AWS resources. See [the AWS Systems Manager documentation](https://docs.aws.amazon.com/systems-manager/latest/userguide/sysman-paramstore-su-create.html#sysman-paramstore-su-create-about) for details on creating these parameters.

tests/integration/datasources_file_test.go

@@ -30,6 +30,15 @@ func (s *FileDatasourcesSuite) SetUpSuite(c *C) {
 A1,B1
 A2,"foo""
 bar"
+`,
+			"test.env": `FOO=a regular unquoted value
+export BAR=another value, exports are ignored
+
+# comments are totally ignored, as are blank lines
+FOO.BAR = "values can be double-quoted, and shell\nescapes are supported"
+
+BAZ = "variable expansion: ${FOO}"
+QUX='single quotes ignore $variables'
 `,
 		}),
 		fs.WithDir("sortorder", fs.WithFiles(map[string]string{
@@ -144,4 +153,15 @@ bar`})
 	zonef = "false"
 }
 `})
+	result = icmd.RunCommand(GomplateBin,
+		"-d", "envfile="+s.tmpDir.Join("test.env"),
+		"-i", `{{ (ds "envfile") | data.ToJSONPretty "  " }}`,
+	)
+	result.Assert(c, icmd.Expected{ExitCode: 0, Out: `{
+  "BAR": "another value, exports are ignored",
+  "BAZ": "variable expansion: a regular unquoted value",
+  "FOO": "a regular unquoted value",
+  "FOO.BAR": "values can be double-quoted, and shell\nescapes are supported",
+  "QUX": "single quotes ignore $variables"
+}`})
 }