reload: preserve configuration path during hot reload

src/flb_reload.c

@@ -533,6 +533,20 @@ int flb_reload(flb_ctx_t *ctx, struct flb_cf *cf_opts)
 
     new_config = new_ctx->config;
 
+    if (old_config->conf_path) {
+        new_config->conf_path = flb_strdup(old_config->conf_path);
+        if (!new_config->conf_path) {
+            if (file != NULL) {
+                flb_sds_destroy(file);
+            }
+            flb_cf_destroy(new_cf);
+            flb_destroy(new_ctx);
+            flb_error("[reload] copying configuration path failed. Reloading is halted");
+            flb_reload_watchdog_cleanup(watchdog_ctx);
+            return FLB_RELOAD_HALTED;
+        }
+    }
+
     /* Inherit verbose from the old ctx instance */
     verbose = ctx->config->verbose;
     new_config->verbose = verbose;

tests/integration/scenarios/hot_reload_watch/config/fluent-bit-relative-parser-after.conf

@@ -0,0 +1,29 @@
+[SERVICE]
+    Flush        1
+    Log_Level    info
+    Parsers_File relative-parser.conf
+    HTTP_Server  On
+    HTTP_Listen  127.0.0.1
+    HTTP_Port    ${FLUENT_BIT_HTTP_MONITORING_PORT}
+    Hot_Reload   On
+
+[INPUT]
+    Name    dummy
+    Tag     relative_parser
+    Samples 1
+    Dummy   {"message":"after"}
+
+[FILTER]
+    Name         parser
+    Match        relative_parser
+    Key_Name     message
+    Parser       reload_test
+    Reserve_Data On
+
+[OUTPUT]
+    Name          opentelemetry
+    Match         relative_parser
+    Host          127.0.0.1
+    Port          ${TEST_SUITE_HTTP_PORT}
+    Logs_URI      /v1/logs
+    Logs_Body_Key $parsed

tests/integration/scenarios/hot_reload_watch/config/fluent-bit-relative-parser-after.yaml

@@ -0,0 +1,32 @@
+service:
+  flush: 1
+  log_level: info
+  parsers_file: relative-parser.conf
+  http_server: on
+  http_port: ${FLUENT_BIT_HTTP_MONITORING_PORT}
+  hot_reload: on
+
+pipeline:
+  inputs:
+    - name: dummy
+      tag: relative_parser
+      samples: 1
+      dummy: |
+        {
+          "message": "after"
+        }
+
+  filters:
+    - name: parser
+      match: relative_parser
+      key_name: message
+      parser: reload_test
+      reserve_data: on
+
+  outputs:
+    - name: opentelemetry
+      match: relative_parser
+      host: 127.0.0.1
+      port: ${TEST_SUITE_HTTP_PORT}
+      logs_uri: /v1/logs
+      logs_body_key: $parsed

tests/integration/scenarios/hot_reload_watch/config/fluent-bit-relative-parser-before.conf

@@ -0,0 +1,29 @@
+[SERVICE]
+    Flush        1
+    Log_Level    info
+    Parsers_File relative-parser.conf
+    HTTP_Server  On
+    HTTP_Listen  127.0.0.1
+    HTTP_Port    ${FLUENT_BIT_HTTP_MONITORING_PORT}
+    Hot_Reload   On
+
+[INPUT]
+    Name    dummy
+    Tag     relative_parser
+    Samples 1
+    Dummy   {"message":"before"}
+
+[FILTER]
+    Name         parser
+    Match        relative_parser
+    Key_Name     message
+    Parser       reload_test
+    Reserve_Data On
+
+[OUTPUT]
+    Name          opentelemetry
+    Match         relative_parser
+    Host          127.0.0.1
+    Port          ${TEST_SUITE_HTTP_PORT}
+    Logs_URI      /v1/logs
+    Logs_Body_Key $parsed

tests/integration/scenarios/hot_reload_watch/config/fluent-bit-relative-parser-before.yaml

@@ -0,0 +1,32 @@
+service:
+  flush: 1
+  log_level: info
+  parsers_file: relative-parser.conf
+  http_server: on
+  http_port: ${FLUENT_BIT_HTTP_MONITORING_PORT}
+  hot_reload: on
+
+pipeline:
+  inputs:
+    - name: dummy
+      tag: relative_parser
+      samples: 1
+      dummy: |
+        {
+          "message": "before"
+        }
+
+  filters:
+    - name: parser
+      match: relative_parser
+      key_name: message
+      parser: reload_test
+      reserve_data: on
+
+  outputs:
+    - name: opentelemetry
+      match: relative_parser
+      host: 127.0.0.1
+      port: ${TEST_SUITE_HTTP_PORT}
+      logs_uri: /v1/logs
+      logs_body_key: $parsed

tests/integration/scenarios/hot_reload_watch/config/relative-parser.conf

@@ -0,0 +1,4 @@
+[PARSER]
+    Name   reload_test
+    Format regex
+    Regex  ^(?<parsed>.*)$

tests/integration/scenarios/hot_reload_watch/tests/test_hot_reload_watch_001.py

@@ -37,17 +37,24 @@
 
 
 class Service:
-    def __init__(self, before_name, after_name):
+    def __init__(self, before_name, after_name, support_files=None):
         self.test_path = os.path.dirname(os.path.abspath(__file__))
         self.config_dir = os.path.abspath(os.path.join(self.test_path, "../config"))
         self.before_config = os.path.join(self.config_dir, before_name)
         self.after_config = os.path.join(self.config_dir, after_name)
+        self.support_files = support_files or []
         self.runtime_dir = tempfile.mkdtemp(prefix="flb-hot-reload-watch-")
-        self.runtime_config = os.path.join(self.runtime_dir, "fluent-bit.yaml")
+        extension = os.path.splitext(before_name)[1]
+        self.runtime_config = os.path.join(self.runtime_dir, f"fluent-bit{extension}")
         data_storage["logs"] = []
 
     def start(self):
         shutil.copyfile(self.before_config, self.runtime_config)
+        for support_file in self.support_files:
+            shutil.copyfile(
+                os.path.join(self.config_dir, support_file),
+                os.path.join(self.runtime_dir, support_file),
+            )
 
         self.flb = FluentBitManager(self.runtime_config)
         self.test_suite_http_port = find_available_port(starting_port=50000)
@@ -96,7 +103,7 @@ def read_message(self, index):
         return payload["resourceLogs"][0]["scopeLogs"][0]["logRecords"][0]["body"]["stringValue"]
 
     def replace_config(self):
-        pending_path = os.path.join(self.runtime_dir, "fluent-bit.yaml.tmp")
+        pending_path = f"{self.runtime_config}.tmp"
         shutil.copyfile(self.after_config, pending_path)
         os.replace(pending_path, self.runtime_config)
 
@@ -178,3 +185,37 @@ def test_hot_reload_http_yaml_config_change():
         assert_reload_result(service)
     finally:
         service.stop()
+
+
+@pytest.mark.parametrize(
+    ("before_name", "after_name"),
+    [
+        ("fluent-bit-relative-parser-before.conf", "fluent-bit-relative-parser-after.conf"),
+        ("fluent-bit-relative-parser-before.yaml", "fluent-bit-relative-parser-after.yaml"),
+    ],
+    ids=["classic", "yaml"],
+)
+def test_hot_reload_http_relative_parser(before_name, after_name):
+    parser_file = "relative-parser.conf"
+
+    # Ensure the parser cannot be loaded relative to the process working directory.
+    assert not os.path.exists(os.path.join(os.getcwd(), parser_file))
+
+    service = Service(before_name, after_name, support_files=[parser_file])
+
+    try:
+        service.start()
+        service.wait_for_log_count(1)
+        assert service.read_message(0) == "before"
+
+        service.replace_config()
+
+        with pytest.raises(TimeoutError):
+            service.flb.wait_for_hot_reload_count(1, timeout=2)
+
+        payload = service.flb.trigger_http_reload()
+        assert payload["reload"] == "done"
+        service.flb.wait_for_hot_reload_count(1)
+        assert_reload_result(service)
+    finally:
+        service.stop()

tests/internal/data/reload/fluent-bit.conf

@@ -2,6 +2,7 @@
     Flush        1
     Daemon       Off
     Log_Level    error
+    Parsers_File parsers.conf
     HTTP_Server  On
     HTTP_Listen  0.0.0.0
     HTTP_Port    2022

tests/internal/data/reload/parsers.conf

@@ -0,0 +1,3 @@
+[PARSER]
+    Name   reload_test
+    Format json

tests/internal/reload.c

@@ -5,6 +5,7 @@
 #include <fluent-bit/flb_kv.h>
 #include <fluent-bit/flb_config_format.h>
 #include <fluent-bit/flb_lib.h>
+#include <fluent-bit/flb_parser.h>
 #include <fluent-bit/flb_reload.h>
 
 #include <cfl/cfl.h>
@@ -22,6 +23,7 @@
 #define FLB_YAML                 FLB_TESTS_DATA_PATH "/data/reload/yaml/processor.yaml"
 #define FLB_YAML_MISSING_INCLUDE FLB_TESTS_DATA_PATH "/data/reload/yaml/missing_include.yaml"
 #define FLB_CLASSIC              FLB_TESTS_DATA_PATH "/data/reload/fluent-bit.conf"
+#define FLB_CLASSIC_PATH         FLB_TESTS_DATA_PATH "/data/reload/"
 
 void test_reconstruct_cf()
 {
@@ -147,11 +149,14 @@ void test_reload()
     cf = flb_cf_create_from_file(cf, FLB_CLASSIC);
     TEST_CHECK(cf != NULL);
 
+    ctx->config->conf_path = flb_strdup(FLB_CLASSIC_PATH);
+    TEST_CHECK(ctx->config->conf_path != NULL);
     ctx->config->conf_path_file = flb_sds_create(FLB_CLASSIC);
     ctx->config->enable_hot_reload = FLB_TRUE;
 
     status = flb_config_load_config_format(ctx->config, cf);
     TEST_CHECK(status == 0);
+    TEST_CHECK(flb_parser_get("reload_test", ctx->config) != NULL);
 
     /* Start the engine */
     status = flb_start(ctx);
@@ -162,12 +167,16 @@ void test_reload()
 
     status = flb_reload(ctx, cf_opts);
     TEST_CHECK(status == 0);
+    TEST_MSG("Expected reload status 0, got %d", status);
 
     sleep(2);
 
     /* flb context should be replaced with flb_reload() */
     ctx = flb_context_get();
 
+    TEST_CHECK(ctx->config->conf_path != NULL &&
+               strcmp(ctx->config->conf_path, FLB_CLASSIC_PATH) == 0);
+    TEST_CHECK(flb_parser_get("reload_test", ctx->config) != NULL);
     TEST_CHECK(mk_list_size(&ctx->config->cf_opts->inputs) == 1);
     TEST_CHECK(mk_list_size(&ctx->config->inputs) == 2);