tests: add processor_invalid.sh test for validating invalid processor handling

This test verifies Fluent Bit's behavior when configured with a non-existent
processor. It checks that Fluent Bit properly fails to start and reports
a relevant error message.

Part of #10305

Author: niedbalski

tests/runtime_shell/CMakeLists.txt

@@ -14,6 +14,7 @@ set(UNIT_TESTS_SH
   in_syslog_uds_dgram_plaintext_expect.sh
   in_syslog_uds_stream_plaintext_expect.sh
   processor_conditional.sh
+  processor_invalid.sh
   )
 
 # Prepare list of unit tests

tests/runtime_shell/processor_invalid.sh

@@ -0,0 +1,67 @@
+#!/bin/sh
+
+# Setup environment if not already set
+if [ -z "$FLB_BIN" ]; then
+    FLB_ROOT=${FLB_ROOT:-$(cd $(dirname $0)/../.. && pwd)}
+    FLB_BIN=${FLB_BIN:-$FLB_ROOT/build/bin/fluent-bit}
+fi
+
+echo "Using Fluent Bit at: $FLB_BIN"
+
+# Create a temporary YAML config file
+cat > /tmp/processor_invalid.yaml << EOL
+service:
+  log_level: debug
+  flush: 1
+pipeline:
+  inputs:
+    - name: dummy
+      dummy: '{"message": "test message"}'
+      tag: test
+      processors:
+        logs:
+          - name: non_existent_processor
+            action: invalid
+
+  outputs:
+    - name: stdout
+      match: '*'
+EOL
+
+echo "Running Fluent Bit with invalid processor YAML config..."
+echo "YAML Config:"
+cat /tmp/processor_invalid.yaml
+
+# Redirect stdout and stderr to a file for analysis
+OUTPUT_FILE="/tmp/processor_invalid_output.txt"
+$FLB_BIN -c /tmp/processor_invalid.yaml -o stdout > $OUTPUT_FILE 2>&1
+
+# Check exit code - we expect it to fail
+EXIT_CODE=$?
+echo "Fluent Bit exited with code: $EXIT_CODE"
+
+# Show the output
+echo "Output file content:"
+cat $OUTPUT_FILE
+
+# Check if the output contains an error related to invalid processor
+INVALID_PROCESSOR=$(grep -c "error creating processor 'non_existent_processor': plugin doesn't exist or failed to initialize" $OUTPUT_FILE || true)
+FAILED_INIT=$(grep -c "error initializing processor" $OUTPUT_FILE || true)
+
+# Clean up
+echo "Cleaning up..."
+rm -f /tmp/processor_invalid.yaml
+rm -f $OUTPUT_FILE
+
+# Check results - we expect Fluent Bit to fail (non-zero exit code)
+# and have an error message about the invalid processor
+if [ "$EXIT_CODE" -ne 0 ] && ([ "$INVALID_PROCESSOR" -gt 0 ] || [ "$FAILED_INIT" -gt 0 ]); then
+    echo "Test passed: Fluent Bit failed with error about invalid processor"
+    exit 0
+else
+    echo "Test failed: Fluent Bit should fail when an invalid processor is configured"
+    echo "Exit code: $EXIT_CODE (expected non-zero)"
+    echo "Invalid processor message count: $INVALID_PROCESSOR (expected > 0)"
+    echo "Failed init message count: $FAILED_INIT (expected > 0)"
+    exit 1
+fi