Issue #120: Add configuration to disable env auto expansion

process-compose.override.yaml

@@ -5,6 +5,7 @@ is_strict: true
 environment:
   - 'ABC=222'
 log_location: ./pc.log
+disable_env_expansion: false
 shell:
   shell_command: "zsh"
   shell_argument: "-c"
@@ -46,7 +47,9 @@ processes:
     ready_log_line: "test loop 1"
 
   dep-on-log-line-ready:
-    command: "echo log is ready"
+    command: "echo log is $ENV_TEST"
+    environment:
+      - 'ENV_TEST=ready'
     availability:
       restart: "on_failure"
       backoff_seconds: 2
@@ -182,7 +185,7 @@ processes:
       - /tmp
       - /
 
-  vim:
+  nvim:
     description: "run a foreground process"
-    command: "vim process-compose.override.yaml"
+    command: "nvim process-compose.override.yaml"
     is_foreground: true

src/loader/loader.go

@@ -89,15 +89,25 @@ func loadProjectFromFile(inputFile string) *types.Project {
 	// .env is optional we don't care if it errors
 	_ = godotenv.Load()
 
-	yamlFile = []byte(os.ExpandEnv(string(yamlFile)))
+	const envEscaped = "##PC_ENV_ESCAPED##"
+	// replace escaped $$ env vars in yaml
+	temp := strings.ReplaceAll(string(yamlFile), "$$", envEscaped)
+	temp = os.ExpandEnv(temp)
+	temp = strings.ReplaceAll(temp, envEscaped, "$")
 
 	project := &types.Project{
 		LogLength: defaultLogLength,
 	}
-	err = yaml.Unmarshal(yamlFile, project)
+	err = yaml.Unmarshal([]byte(temp), project)
 	if err != nil {
 		log.Fatal().Err(err).Msgf("Failed to parse %s", inputFile)
 	}
+	if project.DisableEnvExpansion {
+		err = yaml.Unmarshal(yamlFile, project)
+		if err != nil {
+			log.Fatal().Err(err).Msgf("Failed to parse %s", inputFile)
+		}
+	}
 
 	if err != nil {
 		log.Fatal().Err(err).Msgf("Failed to validate %s", inputFile)

src/types/project.go

@@ -9,18 +9,19 @@ import (
 type Vars map[string]any
 
 type Project struct {
-	Version      string               `yaml:"version"`
-	LogLocation  string               `yaml:"log_location,omitempty"`
-	LogLevel     string               `yaml:"log_level,omitempty"`
-	LogLength    int                  `yaml:"log_length,omitempty"`
-	LoggerConfig *LoggerConfig        `yaml:"log_configuration,omitempty"`
-	LogFormat    string               `yaml:"log_format,omitempty"`
-	Processes    Processes            `yaml:"processes"`
-	Environment  Environment          `yaml:"environment,omitempty"`
-	ShellConfig  *command.ShellConfig `yaml:"shell,omitempty"`
-	IsStrict     bool                 `yaml:"is_strict"`
-	Vars         Vars                 `yaml:"vars"`
-	FileNames    []string
+	Version             string               `yaml:"version"`
+	LogLocation         string               `yaml:"log_location,omitempty"`
+	LogLevel            string               `yaml:"log_level,omitempty"`
+	LogLength           int                  `yaml:"log_length,omitempty"`
+	LoggerConfig        *LoggerConfig        `yaml:"log_configuration,omitempty"`
+	LogFormat           string               `yaml:"log_format,omitempty"`
+	Processes           Processes            `yaml:"processes"`
+	Environment         Environment          `yaml:"environment,omitempty"`
+	ShellConfig         *command.ShellConfig `yaml:"shell,omitempty"`
+	IsStrict            bool                 `yaml:"is_strict"`
+	Vars                Vars                 `yaml:"vars"`
+	DisableEnvExpansion bool                 `yaml:"disable_env_expansion"`
+	FileNames           []string
 }
 
 type ProcessFunc func(process ProcessConfig) error

www/docs/configuration.md

@@ -31,6 +31,7 @@ Default environment variables:
 `PC_REPLICA_NUM` - Defines the process replica number. Useful for port collision avoidance for processes with multiple replicas.
 
 ## .env file
+
 ```.env
 VERSION='1.2.3'
 DB_USER='USERNAME'
@@ -49,6 +50,45 @@ processes:
       - 'OUTPUT_DIR=/path/to/B/data'
 ```
 
+## Disable Automatic Expansion
+
+Process Compose provides 2 ways to disable the automatic environment variables expansion:
+
+1. Escape the environment variables with `$$`. Example:
+   ```yaml
+   processes:
+   	foo:
+     	command: echo I am $$ENV_TEST
+       environment:
+       	- 'ENV_TEST=ready'
+   ```
+
+   **Output**: `I am ready`
+
+2. Globally disable the automatic expansion with `disable_env_expansion: true`. Example:
+   ```yaml
+   disable_env_expansion: true
+   processes:
+   	foo:
+     	command: echo I am $ENV_TEST
+       environment:
+       	- 'ENV_TEST=ready'
+   ```
+
+   **Output**: `I am ready`
+
+>  :bulb: Note: The default behavior for the following `process-compose.yaml`:
+>
+>  ```yaml
+>  processes:
+>  	foo:
+>    	command: echo I am $ENV_TEST
+>      environment:
+>      	- 'ENV_TEST=ready'
+>  ```
+>
+>  **Output**: `I am `
+
 ## Variables
 
 Variables in Process Compose rely on [Go template engine](https://pkg.go.dev/text/template)