[confmap] Use values as string if YAML is invalid (#10794)

<!--Ex. Fixing a bug - Describe the bug and how this fixes the issue.
Ex. Adding a feature - Explain what this achieves.-->
#### Description

<!-- Issue number if applicable -->

If YAML parsing fails, assume the user wanted to pass the value as a
string.

This has the downside that the error messages are less informative: it
will tell you it expected something other than a string instead of the
YAML parser error.

A future improvement could be to pass these errors down as extra
metadata up until the unmarshaling stage.

#### Link to tracking issue

Fixes #10759

<!--Describe what testing was performed and which tests were added.-->
#### Testing

<!--Describe the documentation added.-->

Added test case for this.

.chloggen/mx-psi_fix-invalid-yaml-string.yaml

@@ -0,0 +1,26 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: bug_fix
+
+# The name of the component, or a single word describing the area of concern, (e.g. otlpreceiver)
+component: confmap
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: If loading an invalid YAML string through a provider, use it verbatim instead of erroring out.
+
+# One or more tracking issues or pull requests related to the change
+issues: [10759]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext: | 
+   This makes the ${env:ENV} syntax closer to how ${ENV} worked before unifying syntaxes.
+
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: []

confmap/internal/e2e/types_test.go

@@ -345,6 +345,17 @@ func TestStrictTypeCasting(t *testing.T) {
 			targetField: TargetFieldInlineString,
 			expected:    "inline field with 2006-01-02T15:04:05Z07:00 expansion",
 		},
+		// issue 10759
+		{
+			value:       `["a",`,
+			targetField: TargetFieldString,
+			expected:    `["a",`,
+		},
+		{
+			value:       `["a",`,
+			targetField: TargetFieldInlineString,
+			expected:    `inline field with ["a", expansion`,
+		},
 	}
 
 	previousValue := globalgates.StrictlyTypedInputGate.IsEnabled()

confmap/provider.go

@@ -137,6 +137,11 @@ func withStringRepresentation(stringRepresentation string) RetrievedOption {
 func NewRetrievedFromYAML(yamlBytes []byte, opts ...RetrievedOption) (*Retrieved, error) {
 	var rawConf any
 	if err := yaml.Unmarshal(yamlBytes, &rawConf); err != nil {
+		if globalgates.StrictlyTypedInputGate.IsEnabled() {
+			// If the string is not valid YAML, we try to use it verbatim as a string.
+			strRep := string(yamlBytes)
+			return NewRetrieved(strRep, append(opts, withStringRepresentation(strRep))...)
+		}
 		return nil, err
 	}
 

confmap/provider/envprovider/provider_test.go

@@ -47,11 +47,14 @@ func TestUnsupportedScheme(t *testing.T) {
 }
 
 func TestInvalidYAML(t *testing.T) {
-	const envName = "invalid-yaml"
+	const envName = "invalid_yaml"
 	t.Setenv(envName, "[invalid,")
 	env := createProvider()
-	_, err := env.Retrieve(context.Background(), envSchemePrefix+envName, nil)
-	assert.Error(t, err)
+	ret, err := env.Retrieve(context.Background(), envSchemePrefix+envName, nil)
+	require.NoError(t, err)
+	raw, err := ret.AsRaw()
+	require.NoError(t, err)
+	assert.IsType(t, "", raw)
 	assert.NoError(t, env.Shutdown(context.Background()))
 }
 

confmap/provider/fileprovider/provider_test.go

@@ -47,10 +47,18 @@ func TestNonExistent(t *testing.T) {
 
 func TestInvalidYAML(t *testing.T) {
 	fp := createProvider()
-	_, err := fp.Retrieve(context.Background(), fileSchemePrefix+filepath.Join("testdata", "invalid-yaml.yaml"), nil)
-	assert.Error(t, err)
-	_, err = fp.Retrieve(context.Background(), fileSchemePrefix+absolutePath(t, filepath.Join("testdata", "invalid-yaml.yaml")), nil)
-	assert.Error(t, err)
+	ret, err := fp.Retrieve(context.Background(), fileSchemePrefix+filepath.Join("testdata", "invalid-yaml.yaml"), nil)
+	require.NoError(t, err)
+	raw, err := ret.AsRaw()
+	require.NoError(t, err)
+	assert.IsType(t, "", raw)
+
+	ret, err = fp.Retrieve(context.Background(), fileSchemePrefix+absolutePath(t, filepath.Join("testdata", "invalid-yaml.yaml")), nil)
+	require.NoError(t, err)
+	raw, err = ret.AsRaw()
+	require.NoError(t, err)
+	assert.IsType(t, "", raw)
+
 	require.NoError(t, fp.Shutdown(context.Background()))
 }
 

confmap/provider/internal/configurablehttpprovider/provider_test.go

@@ -282,8 +282,11 @@ func TestInvalidYAML(t *testing.T) {
 		}
 	}))
 	defer ts.Close()
-	_, err := fp.Retrieve(context.Background(), ts.URL, nil)
-	assert.Error(t, err)
+	ret, err := fp.Retrieve(context.Background(), ts.URL, nil)
+	require.NoError(t, err)
+	raw, err := ret.AsRaw()
+	require.NoError(t, err)
+	assert.Equal(t, "wrong : [", raw)
 	require.NoError(t, fp.Shutdown(context.Background()))
 }
 

confmap/provider/yamlprovider/provider_test.go

@@ -8,6 +8,7 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 
 	"go.opentelemetry.io/collector/confmap"
 	"go.opentelemetry.io/collector/confmap/confmaptest"
@@ -26,8 +27,12 @@ func TestEmpty(t *testing.T) {
 
 func TestInvalidYAML(t *testing.T) {
 	sp := createProvider()
-	_, err := sp.Retrieve(context.Background(), "yaml:[invalid,", nil)
-	assert.Error(t, err)
+	ret, err := sp.Retrieve(context.Background(), "yaml:[invalid,", nil)
+	require.NoError(t, err)
+	raw, err := ret.AsRaw()
+	require.NoError(t, err)
+	assert.IsType(t, "", raw)
+
 	assert.NoError(t, sp.Shutdown(context.Background()))
 }
 

confmap/provider_test.go

@@ -56,8 +56,19 @@ func TestNewRetrievedFromYAMLWithOptions(t *testing.T) {
 }
 
 func TestNewRetrievedFromYAMLInvalidYAMLBytes(t *testing.T) {
-	_, err := NewRetrievedFromYAML([]byte("[invalid:,"))
+	ret, err := NewRetrievedFromYAML([]byte("[invalid:,"))
+	require.NoError(t, err)
+
+	_, err = ret.AsConf()
 	assert.Error(t, err)
+
+	str, err := ret.AsString()
+	require.NoError(t, err)
+	assert.Equal(t, "[invalid:,", str)
+
+	raw, err := ret.AsRaw()
+	require.NoError(t, err)
+	assert.Equal(t, "[invalid:,", raw)
 }
 
 func TestNewRetrievedFromYAMLInvalidAsMap(t *testing.T) {