feat: allow template execution to be disabled via env var (resolves #540)

Author: steve-r-west

README.md

@@ -112,7 +112,8 @@ The following environment variables can be set up to control which environment a
 | EPCC_CLIENT_SECRET                  | This is the Client Secret which can be retrieved via CM.                                                                                                                                                                                                                                                                                                             |
 | EPCC_PROFILE                        | A profile name that allows for an independent session and isolation (e.g., distinct histories).                                                                                                                                                                                                                                                                      |
 | EPCC_RUNBOOK_DIRECTORY              | A directory that will be scanned for runbook, a runbook ends with `.epcc.yml`.                                                                                                                                                                                                                                                                                       |
-| EPCC_DISABLE_LEGACY_RESOURCES       | If set disables legacy endpoints from being available.                                                                                                                                                                                                                                                                                                               |   
+| EPCC_DISABLE_LEGACY_RESOURCES       | If set disables legacy endpoints from being available.                                                                                                                                                                                                                                                                                                               |
+| EPCC_CLI_DISABLE_TEMPLATE_EXECUTION | If set to true, `epcc` will not render templates in variabes (i.e., `{{` will be treated literally), recommended when input might be untrusted.                                                                                                                                                                                                                      |
 
 It is recommended to set EPCC_API_BASE_URL, EPCC_CLIENT_ID, and EPCC_CLIENT_SECRET to be able to interact with most things in the CLI.
 

cmd/root.go

@@ -220,14 +220,16 @@ Environment Variables
 - EPCC_BETA_API_FEATURES - Beta features in the API we want to enable.
 - EPCC_CLI_HTTP_HEADER_[0,1,...] - An additional HTTP header to set with all requests, the format should be "HeaderName: value"
 - EPCC_PROFILE - The name of the profile we will use (isolates namespace, credentials, etc...)
-
+- EPCC_CLI_DISABLE_TLS_VERIFICATION - Disables TLS verification
+- EPCC_RUNBOOK_DIRECTORY - Directory to scan for additional runbooks
+- EPCC_CLI_DISABLE_TEMPLATE_EXECUTION - Disables template execution (recommended if input is untrusted).
 `,
 		PersistentPreRunE: func(cmd *cobra.Command, args []string) error {
 			log.SetLevel(logger.Loglevel)
 
-			env := config.GetEnv()
-			if env.EPCC_RATE_LIMIT != 0 {
-				rateLimit = env.EPCC_RATE_LIMIT
+			e := config.GetEnv()
+			if e.EPCC_RATE_LIMIT != 0 {
+				rateLimit = e.EPCC_RATE_LIMIT
 			}
 			authentication.Initialize()
 

config/config.go

@@ -3,14 +3,15 @@ package config
 import "sync/atomic"
 
 type Env struct {
-	EPCC_API_BASE_URL                  string `env:"EPCC_API_BASE_URL"`
-	EPCC_CLIENT_ID                     string `env:"EPCC_CLIENT_ID"`
-	EPCC_CLIENT_SECRET                 string `env:"EPCC_CLIENT_SECRET"`
-	EPCC_BETA_API_FEATURES             string `env:"EPCC_BETA_API_FEATURES"`
-	EPCC_RATE_LIMIT                    uint16 `env:"EPCC_RATE_LIMIT"`
-	EPCC_CLI_SUPPRESS_NO_AUTH_MESSAGES bool   `env:"EPCC_CLI_SUPPRESS_NO_AUTH_MESSAGES"`
-	EPCC_RUNBOOK_DIRECTORY             string `env:"EPCC_RUNBOOK_DIRECTORY"`
-	EPCC_DISABLE_LEGACY_RESOURCES      bool   `env:"EPCC_DISABLE_LEGACY_RESOURCES"`
+	EPCC_API_BASE_URL                   string `env:"EPCC_API_BASE_URL"`
+	EPCC_CLIENT_ID                      string `env:"EPCC_CLIENT_ID"`
+	EPCC_CLIENT_SECRET                  string `env:"EPCC_CLIENT_SECRET"`
+	EPCC_BETA_API_FEATURES              string `env:"EPCC_BETA_API_FEATURES"`
+	EPCC_RATE_LIMIT                     uint16 `env:"EPCC_RATE_LIMIT"`
+	EPCC_CLI_SUPPRESS_NO_AUTH_MESSAGES  bool   `env:"EPCC_CLI_SUPPRESS_NO_AUTH_MESSAGES"`
+	EPCC_RUNBOOK_DIRECTORY              string `env:"EPCC_RUNBOOK_DIRECTORY"`
+	EPCC_DISABLE_LEGACY_RESOURCES       bool   `env:"EPCC_DISABLE_LEGACY_RESOURCES"`
+	EPCC_CLI_DISABLE_TEMPLATE_EXECUTION bool   `env:"EPCC_CLI_DISABLE_TEMPLATE_EXECUTION"`
 }
 
 var env = atomic.Pointer[Env]{}

external/templates/template.go

@@ -3,6 +3,7 @@ package templates
 import (
 	"bytes"
 	"github.com/Masterminds/sprig/v3"
+	"github.com/elasticpath/epcc-cli/config"
 	log "github.com/sirupsen/logrus"
 	"strings"
 	"text/template"
@@ -13,6 +14,10 @@ func init() {
 }
 func Render(templateString string) string {
 
+	if config.GetEnv().EPCC_CLI_DISABLE_TEMPLATE_EXECUTION {
+		return templateString
+	}
+
 	if !strings.Contains(templateString, "{{") {
 		return templateString
 	}