Refactor to add MQTT integration

.clang-format

@@ -1,3 +1,3 @@
 ---
 BasedOnStyle: LLVM
-ColumnLimit: 120
+ColumnLimit: 140

.github/workflows/make.yml

@@ -6,15 +6,32 @@ on:
   pull_request:
     branches: [ "master" ]
 
+permissions:
+  contents: read
+
 jobs:
   build:
+    runs-on: ubuntu-latest
+    continue-on-error: true  # FIXME: remove when gcc build is passing
+    strategy:
+      fail-fast: false
+      matrix:
+        cc: [clang, gcc]
+    steps:
+      - uses: actions/checkout@v4
+      - uses: awalsh128/cache-apt-pkgs-action@latest
+        with:
+          packages: ${{ matrix.cc }} libbsd-dev libconfig-dev libmodbus-dev libmosquitto-dev
+      - name: make with ${{ matrix.cc }}
+        run: env CC=${{ matrix.cc }} make
+  test:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3
-    - uses: awalsh128/cache-apt-pkgs-action@latest
-      with:
-        packages: clang libbsd-dev libmodbus-dev
-    - name: make
-      run: make
-    - name: make lint
-      run: make lint
+      - uses: actions/checkout@v4
+      - uses: awalsh128/cache-apt-pkgs-action@latest
+        with:
+          packages: clang libbsd-dev libconfig-dev libmodbus-dev libmosquitto-dev mosquitto-clients
+      - name: make lint
+        run: env CC=clang make lint
+      - name: make test
+        run: env CC=clang make test

.gitignore

@@ -1,2 +1,4 @@
 /deploy.sh
 /growatt
+/html/
+/tests/mock-server

Makefile

@@ -1,19 +1,29 @@
-CC=clang
-RM=rm -f
-CFLAGS=$(shell pkg-config --cflags libbsd libmodbus)
-LIBS=$(shell pkg-config --libs libbsd libmodbus) -pthread
-
-SRCS=src/growatt.c src/*.h
+CC?=clang
+#CC?=gcc
+RM=rm -fv
+CFLAGS=$(shell pkg-config --cflags libbsd libconfig libmodbus libmosquitto)
+LIBS=$(shell pkg-config --libs libbsd libconfig libmodbus libmosquitto) -pthread
+SRCS=src/*
+TESTS=tests/*.c
 
 all: growatt
 
+doc: $(SRCS)
+	doxygen .doxygen
+
 growatt: $(SRCS)
-	$(CC) $(CFLAGS) $(LIBS) -Wall -Werror -pedantic -O3 -o growatt src/growatt.c
+	$(CC) -v $(CFLAGS) $(LIBS) -Wall -Werror -O3 -o growatt src/*.c
 
 lint:
-	clang-format --verbose --Werror -i --style=file src/*
-	clang-tidy --checks='*,-altera-id-dependent-backward-branch,-altera-unroll-loops,-cert-err33-c,-clang-analyzer-security.insecureAPI.DeprecatedOrUnsafeBufferHandling,-llvm-header-guard,-llvmlibc-restrict-system-libc-headers,-readability-function-cognitive-complexity' --format-style=llvm src/* -- $(CFLAGS)
+	clang-format --verbose --Werror -i --style=file $(SRCS) $(TESTS)
+	clang-tidy --checks='*,-altera-id-dependent-backward-branch,-altera-unroll-loops,-bugprone-assignment-in-if-condition,-cert-err33-c,-clang-analyzer-security.insecureAPI.DeprecatedOrUnsafeBufferHandling,-cppcoreguidelines-avoid-magic-numbers,-llvm-header-guard,-llvmlibc-restrict-system-libc-headers,-readability-function-cognitive-complexity' --format-style=llvm $(SRCS) $(TESTS) -- $(CFLAGS)
 .PHONY: lint
 
+test: growatt $(TESTS)
+	$(CC) -v $(shell pkg-config --libs --cflags libbsd libmodbus) -Wall -Werror -o tests/mock-server $(TESTS)
+	timeout 30 mosquitto_sub -h test.mosquitto.org -p 1884 -u rw -P readwrite -t homeassistant/sensor/growatt/state -d &
+	./tests/mock-server &
+	./growatt config-example.conf || true
+
 clean:
-	$(RM) growatt
+	$(RM) growatt tests/mock-server

README.md

@@ -7,7 +7,7 @@ This allows to monitor PV production, battery status, etc. on a nice Grafana int
 ## Build
 
 ```bash
-apt install clang libbsd-dev libmodbus-dev
+apt install clang libbsd-dev libconfig-dev libmodbus-dev libmosquitto-dev mosquitto-clients
 make
 ```
 
@@ -19,6 +19,12 @@ The "Growatt OffGrid SPF5000 Modbus RS485 RTU Protocol" PDF document has been a
 
 Would like to monitor Epever/Epsolar Tracer solar charge controllers instead? Here is a sister repository for that: https://github.com/infertux/epever_exporter
 
+## Other approaches
+
+- Blog post: https://www.splitbrain.org/blog/2023-11/03-growatt_and_home_assistant
+- Reading Modbus registers via Home Assistant: https://github.com/home-assistant/core/issues/94149
+- https://github.com/rspring/Esphome-Growatt
+
 ## License
 
 AGPLv3+

TODO

@@ -0,0 +1,5 @@
+- add program option --verbose instead of compile-time LOG_VERBOSE define
+- test program with either --mqtt XOR --prometheus but not both
+- go through commented code
+- fix all lint warnings
+- use condition variables to exit all threads cleanly?

config-example.conf

@@ -0,0 +1,16 @@
+// Block device path or host:port to connect to (required)
+# device_or_uri = "/dev/ttyUSB0"
+device_or_uri = "127.0.0.1:1502"
+
+// Prometheus config (optional block)
+prometheus = {
+  port = 1234
+}
+
+// MQTT config (optional block)
+mqtt = {
+  host = "test.mosquitto.org"
+  port = 1884
+  username = "wo"
+  password = "writeonly"
+}

config-minimal.conf

@@ -0,0 +1,4 @@
+device_or_uri = "127.0.0.1:1502"
+prometheus = {
+  port = 1234
+}

docker-build.sh

@@ -4,28 +4,28 @@ set -euxo pipefail
 
 cd "$(dirname "$0")"
 
-target="${1:-growatt}"
-interactive="${2:-}"
-container=${target}-builder
+channel="${1:-stable}" # can be overriden with "bullseye" for example
+target=growatt
+container=${target}-builder-${channel}
 volume=/root/HOST
-channel=stable
+cc=clang-13
 
 if [ -z "${FAST:-}" ]; then
-    docker pull debian:${channel}
+    docker pull "debian:${channel}"
 
-    [ "$(docker ps -qaf "name=${container}")" ] || docker run --name $container -d -t -v "${PWD}:${volume}" debian:${channel}
+    [ "$(docker ps -qaf "name=${container}")" ] || docker run --name "$container" --detach --tty --volume "${PWD}:${volume}" --network host "debian:${channel}"
 
-    docker start $container
+    docker start "$container"
 
-    docker exec $container dpkg --configure -a
-    docker exec $container bash -c "echo \"deb http://ftp.sg.debian.org/debian ${channel} main\" | tee /etc/apt/sources.list"
-    docker exec $container apt-get update
-    docker exec $container apt-get upgrade -y
-    docker exec $container apt-get install -y make clang pkg-config
-    docker exec $container apt-get install -y libbsd-dev libmodbus-dev
-    docker exec $container apt-get autoremove -y --purge
+    docker exec "$container" dpkg --configure -a
+    docker exec "$container" apt-get update
+    docker exec "$container" apt-get upgrade -y
+    docker exec "$container" apt-get install -y $cc
+    docker exec "$container" apt-get install -y make pkg-config
+    docker exec "$container" apt-get install -y libbsd-dev libconfig-dev libmodbus-dev libmosquitto-dev
+    docker exec "$container" apt-get autoremove -y --purge
 fi
 
-docker exec --workdir "${volume}" $container rm -fv $target
-docker exec --workdir "${volume}" $container make $target
-docker exec --workdir "${volume}" $container ls -l $target
+docker exec --workdir "${volume}" "$container" rm -fv $target
+docker exec --workdir "${volume}" "$container" env CC=$cc make $target
+docker exec --workdir "${volume}" "$container" ls -l $target

src/growatt.c

@@ -1,40 +1,152 @@
 // SPDX-License-Identifier: AGPL-3.0-or-later
 
+#include <assert.h>
+#include <libconfig.h>
 #include <limits.h>
 #include <stdio.h>
 #include <stdlib.h>
 
-#include "http.h"
 #include "log.h"
-
-#define MAX_PORT_NUMBER USHRT_MAX
+#include "mqtt.h"
+#include "prometheus.h"
 
 enum {
-  MAX_DEVICES = 8,
   RADIX_DECIMAL = 10,
+  STDC_VERSION_MIN = 201710L,
 };
 
-int main(int argc, char *argv[]) {
-  if (argc != 3) {
-    fprintf(LOG_ERROR, "Usage: %s <device_id[,device2_id]> <port>\n", argv[0]);
-    fprintf(LOG_ERROR, "Example: %s 1 1234\n", argv[0]);
-    fprintf(LOG_ERROR, "Example: %s 1,2 1234\n", argv[0]);
+typedef struct __attribute__((aligned(64))) {
+  const char *device_or_uri;
+  prometheus_config prometheus_config;
+  mqtt_config mqtt_config;
+} config;
+
+static int usage(char const program[static 1]) {
+  fprintf(stderr, "Usage: %s <config_file>\n", program);
+  fprintf(stderr, "Example: %s /etc/growatt-exporter.conf\n", program);
+  return EXIT_FAILURE;
+}
+
+static int join_thread(thrd_t const *thread, char const label[static 1]) {
+  int value = 0;
+  int code = thrd_join(*thread, &value);
+
+  if (code != thrd_success || value != EXIT_SUCCESS) {
+    LOG(LOG_ERROR, "Thread %s failed with value %d (code = %d)", label, value, code);
+
+    keep_running = 0;
+
+    if (!strcmp(label, "MDBS")) {
+      stop_prometheus_thread();
+      // kill(SIGTERM, 0);
+    }
+  } else {
+    LOG(LOG_INFO, "Thread %s exited successfully", label);
+  }
+
+  return value;
+}
+
+/*static void sig_handler(int signal)
+{
+  LOG(LOG_INFO, "Got signal %d", signal);
+  keep_running = 0;
+}*/
+
+int parse_config(config *config, config_t *parser, char const *filename) {
+  if (!config_read_file(parser, filename)) {
+    LOG(LOG_ERROR, "%s:%d - %s\n", config_error_file(parser), config_error_line(parser), config_error_text(parser));
     return EXIT_FAILURE;
   }
 
-  uint8_t device_ids[MAX_DEVICES] = {0};
-  uint8_t current_device_id = 0;
-  char *device_id = NULL;
-  char *rest = argv[1];
-  while ((device_id = strtok_r(rest, ",", &rest))) {
-    device_ids[current_device_id++] = strtol(device_id, NULL, RADIX_DECIMAL);
+  if (CONFIG_TRUE != config_lookup_string(parser, "device_or_uri", &config->device_or_uri)) {
+    LOG(LOG_ERROR, "No 'device_or_uri' setting in configuration file");
+    return EXIT_FAILURE;
+  }
+
+  if (CONFIG_TRUE != config_lookup_int(parser, "prometheus.port", &config->prometheus_config.port)) {
+    config->prometheus_config.port = 0;
+  }
+
+  if (CONFIG_TRUE != config_lookup_int(parser, "mqtt.port", &config->mqtt_config.port)) {
+    config->mqtt_config.port = 0;
   }
 
-  const uint16_t port = strtol(argv[2], NULL, RADIX_DECIMAL);
-  if (port < 1 || port > MAX_PORT_NUMBER) {
-    fprintf(LOG_ERROR, "Invalid port number: %d\n", port);
+  config_lookup_string(parser, "mqtt.host", &config->mqtt_config.host);
+  config_lookup_string(parser, "mqtt.username", &config->mqtt_config.username);
+  config_lookup_string(parser, "mqtt.password", &config->mqtt_config.password);
+
+  return EXIT_SUCCESS;
+}
+
+int main(int argc, char *argv[argc + 1]) {
+  static_assert(__STDC_VERSION__ >= STDC_VERSION_MIN, "C17+ required");
+
+  // disable log buffering
+  setbuf(stdout, NULL);
+  setbuf(stderr, NULL);
+
+  // signal(SIGINT, sig_handler);
+
+  if (argc < 2) {
+    return usage(argv[0]);
+  }
+
+  config config;
+  config_t parser_config;
+  config_init(&parser_config);
+  if (parse_config(&config, &parser_config, argv[1])) {
+    config_destroy(&parser_config);
+    return EXIT_FAILURE;
+  }
+
+  thrd_t prometheus_thread = 0;
+  thrd_t mqtt_thread = 0;
+  thrd_t modbus_thread = 0;
+
+  if (config.prometheus_config.port) {
+    int status = thrd_create(&prometheus_thread, (thrd_start_t)start_prometheus_thread, &config.prometheus_config);
+    if (status != thrd_success) {
+      PERROR("thrd_create() failed");
+      config_destroy(&parser_config);
+      return EXIT_FAILURE;
+    }
+  }
+
+  if (config.mqtt_config.port) {
+    int status = thrd_create(&mqtt_thread, (thrd_start_t)start_mqtt_thread, &config.mqtt_config);
+    if (status != thrd_success) {
+      PERROR("thrd_create() failed");
+      config_destroy(&parser_config);
+      return EXIT_FAILURE;
+    }
+  }
+
+  if (!prometheus_thread && !mqtt_thread) {
+    LOG(LOG_ERROR, "You must configure at least Prometheus or MQTT (or both)");
+    config_destroy(&parser_config);
+    return EXIT_FAILURE;
+  }
+
+  int status = thrd_create(&modbus_thread, (thrd_start_t)start_modbus_thread, (void *)config.device_or_uri);
+  if (status != thrd_success) {
+    PERROR("thrd_create() failed");
+    config_destroy(&parser_config);
     return EXIT_FAILURE;
   }
 
-  return http(port, device_ids);
+  // FIXME: catch MQTT thread termination somehow
+  int value = join_thread(&modbus_thread, "MDBS");
+
+  if (prometheus_thread) {
+    value += join_thread(&prometheus_thread, "PRMT");
+  }
+  if (mqtt_thread) {
+    value += join_thread(&mqtt_thread, "MQTT");
+  }
+
+  config_destroy(&parser_config);
+
+  LOG(LOG_INFO, "Bye");
+  exit(value); // will terminate any remaining threads
 }