chore(cli)!: Update default for --strict-env-vars to true (#20062)

This deprecates this option.

Signed-off-by: Jesse Szwedko <[email protected]>

changelog.d/deprecate_strict_env_vars.breaking.md

@@ -0,0 +1,4 @@
+The default of `--strict-env-vars` has been changed to `true`. This option has been deprecated. In
+a future version it will be removed and Vector will have the behavior it currently has when set
+to `true` which is that missing environment variables will cause Vector to fail to start up with an
+error instead of a warning.

docs/DEPRECATIONS.md

@@ -16,7 +16,7 @@ For example:
 
 ## To be migrated
 
-- v0.37.0 strict_env_vars Change the default for missing environment variable interpolation from
-  warning to erroring.
-
 ## To be removed
+
+- v0.38.0 strict_env_vars Remove option for configuring missing environment variable interpolation
+  to be a warning rather than an error

src/cli.rs

@@ -213,11 +213,12 @@ pub struct RootOpts {
     #[arg(long, env = "VECTOR_ALLOW_EMPTY_CONFIG", default_value = "false")]
     pub allow_empty_config: bool,
 
-    /// Turn on strict mode for environment variable interpolation. When set, interpolation of a
-    /// missing environment variable in configuration files will cause an error instead of a
-    /// warning, which will result in a failure to load any such configuration file. This defaults
-    /// to false, but that default is deprecated and will be changed to strict in future versions.
-    #[arg(long, env = "VECTOR_STRICT_ENV_VARS", default_value = "false")]
+    /// Turn on strict mode for environment variable interpolation. When set, interpolation of
+    /// a missing environment variable in configuration files will cause an error instead of
+    /// a warning, which will result in a failure to load any such configuration file. This option
+    /// is deprecated and will be removed in a future version to remove the ability to downgrade
+    /// missing environment variables to warnings.
+    #[arg(long, env = "VECTOR_STRICT_ENV_VARS", default_value = "true")]
     pub strict_env_vars: bool,
 }
 

website/cue/reference/cli.cue

@@ -658,9 +658,13 @@ cli: {
 		}
 		VECTOR_STRICT_ENV_VARS: {
 			description: """
-				Turn on strict mode for environment variable interpolation. When set, interpolation of a missing environment variable in configuration files will cause an error instead of a warning, which will result in a failure to load any such configuration file. This defaults to false, but that default is deprecated and will be changed to strict in future versions.
+				Turn on strict mode for environment variable interpolation. When set, interpolation of a missing
+				environment variable in configuration files will cause an error instead of a warning, which will
+				result in a failure to load any such configuration file. This option is deprecated and will be
+				removed in a future version to remove the ability to downgrade missing environment variables to
+				warnings.
 				"""
-			type: bool: default: false
+			type: bool: default: true
 		}
 	}