feat: implement substitute command for the native CLI (#65)

`ngssc substitute` substitutes the variable ${NGSSC_CSP_HASH} in files ending with ".template"
and copies the file while removing the ".template" extension.

${NGSSC_CSP_HASH} represents the CSP hash value of the IIFE generated/inserted by the
insert command, wrapped by single quotes.

By default looks for "*.template" files in the current working directory. Specify another
directory to search for "*.template" files via argument.
(e.g. ngssc substitute /path/to/template/files)

When applying the variable(s), the file is copied to the same directory without the
".template" extension with the substituion applied.
(e.g. ngssc substitute: /a/my.conf.template => /a/my.conf)

Use the "--out" flag to define a different output directory.
(e.g. ngssc substitute --out=/b: /a/my.conf.template => /b/my.conf)

Optionally supports substituting environment variables with the --include-env flag.
The format ${EXAMPLE} must be used ($EXAMPLE will not work). Additionally only
alphanumeric characters and _ are allowed as variable names (e.g. ${EXAMPLE_KEY}).
(e.g. ngssc substitute --include-env)

Closes #64

Author: kyubisation

.gitignore

@@ -20,6 +20,9 @@ coverage
 # nyc test coverage
 .nyc_output
 
+# Golang coverage
+cli/coverage.out
+
 # Grunt intermediate storage (http://gruntjs.com/creating-plugins#storing-task-files)
 .grunt
 

README.md

@@ -105,7 +105,7 @@ export const environment = {
 };
 ```
 
-#### NG_ENV.\* _Deprecated_
+#### NG\_ENV.\* *Deprecated*
 
 Import NG_ENV from `angular-server-side-configuration/ng-env`
 and use NG_ENV.NAME in your environment.prod.ts, where NAME is the
@@ -157,13 +157,54 @@ if you need an additional environment.)
 
 #### ngssc insert
 
+Insert environment variables. Looks for an ngssc.json file inside the current or
+given directory. Directory defaults to current working directory.
+
 Usage: ngssc insert [options] [directory]
 
 | Options           | Description                                                                       |
 | ----------------- | --------------------------------------------------------------------------------- |
-| `-r, --recursive` | Recursively searches for ngssc.json files and applies the contained configuration |
+| `--recursive, -r` | Recursively searches for ngssc.json files and applies the contained configuration |
 | `--dry`           | Perform the insert without actually inserting the variables                       |
 
+#### ngssc substitute
+
+Substitutes the variable \$\{NGSSC_CSP_HASH\} in files ending with ".template"
+and copies the file while removing the ".template" extension.
+
+\$\{NGSSC_CSP_HASH\} represents the CSP hash value of the IIFE generated/inserted by the
+insert command, wrapped by single quotes.
+
+By default looks for "\*.template" files in the current working directory. Specify another
+directory to search for "\*.template" files via argument.
+(e.g. `ngssc substitute /path/to/template/files`)
+
+When applying the variable(s), the file is copied to the same directory without the
+".template" extension with the substituion applied.
+(e.g. `ngssc substitute`: /a/my.conf.template => /a/my.conf)
+
+Use the "--out" flag to define a different output directory.
+(e.g. `ngssc substitute --out=/b`: /a/my.conf.template => /b/my.conf)
+
+Optionally supports substituting environment variables with the --include-env flag.
+The format \$\{EXAMPLE\} must be used (\$EXAMPLE will not work). Additionally only
+alphanumeric characters and \_ are allowed as variable names (e.g. \$\{EXAMPLE_KEY\}).
+(e.g. `ngssc substitute --include-env`)
+
+**ATTENTION**: Since the official nginx container image already provides a similar mechanism
+with substitution, it is recommended **not** to use the `/etc/nginx/templates` directory.
+Instead use the directory `/etc/nginx/ngssc-templates`.
+
+Usage: ngssc substitute [options] [directory]
+
+| Options                | Description                                                                                                                                                                                                                                 |
+| ---------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| `--ngssc-path`         | Path to the ngssc.json file or containing directory to be used for the generated IIFE. Supports glob. Defaults to [current working directory]/\*\*/ngssc.json. Throws if multiple ngssc.json with different variant or variables are found. |
+| `--hash-algorithm, -a` | The hash algorithm to be used. Supports sha256, sha384 and sha512. Defaults to sha512.                                                                                                                                                      |
+| `--out, -o`            | The directory into which the updated files should be copied.                                                                                                                                                                                |
+| `--include-env, -e`    | Substitute all variables in the format of \$\{VARIABLE_NAME\}.                                                                                                                                                                              |
+| `--dry`                | Perform the insert without actually inserting the variables                                                                                                                                                                                 |
+
 ##### Minimal Example
 
 Dockerfile
@@ -188,6 +229,9 @@ ngssc.sh
 ```bash
 #!/bin/sh
 ngssc insert /usr/share/nginx/html
+# Substitute CSP variable (and optionally environment variables)
+# See documentation above
+#ngssc substitute --ngssc-path=/usr/share/nginx/html -o=/etc/nginx/conf.d/ /etc/nginx/ngssc-templates/
 ```
 
 ### ngssc.json

cli/commands/insert.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"bytes"
+	"fmt"
 	"io"
 	"io/ioutil"
 	"os"
@@ -59,36 +60,25 @@ func (result TestResult) StdoutContains(pattern string) bool {
 	return strings.Contains(result.Stdout(), pattern)
 }
 
-type TestIOContext struct {
+type TestDir struct {
 	path string
 }
 
-func NewTestIOContext(t *testing.T) TestIOContext {
-	dir, err := ioutil.TempDir("", "ngssc_test")
-	if err != nil {
-		panic(err)
-	}
-
-	context := TestIOContext{path: dir}
-	t.Cleanup(func() {
-		err := os.RemoveAll(context.path)
-		if err != nil {
-			panic(err)
-		}
-	})
-	return context
+func newTestDir(t *testing.T) TestDir {
+	dir := t.TempDir()
+	return TestDir{path: dir}
 }
 
-func (context TestIOContext) CreateFile(fileName string, content string) {
+func (context TestDir) CreateFile(fileName string, content string) {
 	filePath := filepath.Join(context.path, fileName)
 	ioutil.WriteFile(filePath, []byte(content), 0644)
 }
 
-func (context TestIOContext) FileContains(fileName string, pattern string) bool {
+func (context TestDir) FileContains(fileName string, pattern string) bool {
 	return strings.Contains(context.ReadFile(fileName), pattern)
 }
 
-func (context TestIOContext) ReadFile(fileName string) string {
+func (context TestDir) ReadFile(fileName string) string {
 	filePath := filepath.Join(context.path, fileName)
 	fileContent, err := ioutil.ReadFile(filePath)
 	if err != nil {
@@ -98,13 +88,89 @@ func (context TestIOContext) ReadFile(fileName string) string {
 	return string(fileContent)
 }
 
-func (context TestIOContext) CreateLanguageContext(language string) TestIOContext {
+func (context TestDir) CreateDirectory(language string) TestDir {
 	path := filepath.Join(context.path, language)
 	err := os.Mkdir(path, 0755)
 	if err != nil {
 		panic(err)
 	}
 
-	languageContext := TestIOContext{path}
-	return languageContext
+	return TestDir{path}
+}
+
+func chdir(t *testing.T, dir string) {
+	t.Helper()
+	wd, err := os.Getwd()
+	if err != nil {
+		t.Fatalf("chdir %s: %v", dir, err)
+	}
+	if err := os.Chdir(dir); err != nil {
+		t.Fatal(err)
+	}
+
+	t.Cleanup(func() {
+		if err := os.Chdir(wd); err != nil {
+			t.Fatalf("restoring working directory: %v", err)
+		}
+	})
+}
+
+func tmpEnv(t *testing.T, key string, value string) {
+	os.Setenv("TEST_VALUE", "example value")
+
+	t.Cleanup(func() {
+		os.Unsetenv("TEST_VALUE")
+	})
+}
+
+func assertContains(t *testing.T, s string, substring string, message string) {
+	t.Helper()
+	debugMessage := fmt.Sprintf("Expected %v to contain %v", s, substring)
+	assertTrue(t, strings.Contains(s, substring), appendDebugMessage(message, debugMessage))
+}
+
+func assertNotContains(t *testing.T, s string, substring string, message string) {
+	t.Helper()
+	debugMessage := fmt.Sprintf("Expected %v to not contain %v", s, substring)
+	assertTrue(t, !strings.Contains(s, substring), appendDebugMessage(message, debugMessage))
+}
+
+func assertEqual(t *testing.T, a interface{}, b interface{}, message string) {
+	t.Helper()
+	assertTrue(t, a == b, appendDebugMessage(message, fmt.Sprintf("%v != %v", a, b)))
+}
+
+func assertFailure(t *testing.T, result TestResult) {
+	t.Helper()
+	if !result.Success() {
+		return
+	}
+	t.Fatalf("Expected to fail, but succeeded: %v %v", result.Stdout(), result.Error())
+}
+
+func assertSuccess(t *testing.T, result TestResult) {
+	t.Helper()
+	if result.Success() {
+		return
+	}
+	t.Fatalf("Expected to succeed, but failed: %v %v", result.Stdout(), result.Error())
+}
+
+func assertTrue(t *testing.T, v bool, message string) {
+	t.Helper()
+	if v {
+		return
+	}
+	if len(message) == 0 {
+		message = "Expected value to be true"
+	}
+	t.Fatal(message)
+}
+
+func appendDebugMessage(message string, debugMessage string) string {
+	if len(message) == 0 {
+		return debugMessage
+	} else {
+		return message + "\n" + debugMessage
+	}
 }