[syslog] Implement logging via syslog (#8637)

Co-authored-by: Jesse Hills <3060199+jesserockz@users.noreply.github.com>

CODEOWNERS

@@ -429,6 +429,7 @@ esphome/components/sun/* @OttoWinter
 esphome/components/sun_gtil2/* @Mat931
 esphome/components/switch/* @esphome/core
 esphome/components/switch/binary_sensor/* @ssieb
+esphome/components/syslog/* @clydebarrow
 esphome/components/t6615/* @tylermenezes
 esphome/components/tc74/* @sethgirvan
 esphome/components/tca9548a/* @andreashergert1984

esphome/components/syslog/__init__.py

@@ -0,0 +1,41 @@
+import esphome.codegen as cg
+from esphome.components import udp
+from esphome.components.logger import LOG_LEVELS, is_log_level
+from esphome.components.time import RealTimeClock
+from esphome.components.udp import CONF_UDP_ID
+import esphome.config_validation as cv
+from esphome.const import CONF_ID, CONF_LEVEL, CONF_PORT, CONF_TIME_ID
+from esphome.cpp_types import Component, Parented
+
+CODEOWNERS = ["@clydebarrow"]
+
+DEPENDENCIES = ["udp", "logger", "time"]
+
+syslog_ns = cg.esphome_ns.namespace("syslog")
+Syslog = syslog_ns.class_("Syslog", Component, Parented.template(udp.UDPComponent))
+
+CONF_STRIP = "strip"
+CONF_FACILITY = "facility"
+CONFIG_SCHEMA = udp.UDP_SCHEMA.extend(
+    {
+        cv.GenerateID(): cv.declare_id(Syslog),
+        cv.GenerateID(CONF_TIME_ID): cv.use_id(RealTimeClock),
+        cv.Optional(CONF_PORT, default=514): cv.port,
+        cv.Optional(CONF_LEVEL, default="DEBUG"): is_log_level,
+        cv.Optional(CONF_STRIP, default=True): cv.boolean,
+        cv.Optional(CONF_FACILITY, default=16): cv.int_range(0, 23),
+    }
+)
+
+
+async def to_code(config):
+    parent = await cg.get_variable(config[CONF_UDP_ID])
+    time = await cg.get_variable(config[CONF_TIME_ID])
+    cg.add(parent.set_broadcast_port(config[CONF_PORT]))
+    cg.add(parent.set_should_broadcast())
+    level = LOG_LEVELS[config[CONF_LEVEL]]
+    var = cg.new_Pvariable(config[CONF_ID], level, time)
+    await cg.register_component(var, config)
+    await cg.register_parented(var, parent)
+    cg.add(var.set_strip(config[CONF_STRIP]))
+    cg.add(var.set_facility(config[CONF_FACILITY]))

esphome/components/syslog/esphome_syslog.cpp

@@ -0,0 +1,49 @@
+#include "esphome_syslog.h"
+
+#include "esphome/components/logger/logger.h"
+#include "esphome/core/application.h"
+#include "esphome/core/time.h"
+
+namespace esphome {
+namespace syslog {
+
+// Map log levels to syslog severity using an array, indexed by ESPHome log level (1-7)
+constexpr int LOG_LEVEL_TO_SYSLOG_SEVERITY[] = {
+    3,  // NONE
+    3,  // ERROR
+    4,  // WARN
+    5,  // INFO
+    6,  // CONFIG
+    7,  // DEBUG
+    7,  // VERBOSE
+    7   // VERY_VERBOSE
+};
+
+void Syslog::setup() {
+  logger::global_logger->add_on_log_callback(
+      [this](int level, const char *tag, const char *message) { this->log_(level, tag, message); });
+}
+
+void Syslog::log_(const int level, const char *tag, const char *message) const {
+  if (level > this->log_level_)
+    return;
+  // Syslog PRI calculation: facility * 8 + severity
+  int severity = 7;
+  if ((unsigned) level <= 7) {
+    severity = LOG_LEVEL_TO_SYSLOG_SEVERITY[level];
+  }
+  int pri = this->facility_ * 8 + severity;
+  auto timestamp = this->time_->now().strftime("%b %d %H:%M:%S");
+  unsigned len = strlen(message);
+  // remove color formatting
+  if (this->strip_ && message[0] == 0x1B && len > 11) {
+    message += 7;
+    len -= 11;
+  }
+
+  auto data = str_sprintf("<%d>%s %s %s: %.*s", pri, timestamp.c_str(), App.get_name().c_str(), tag, len, message);
+  this->parent_->send_packet((const uint8_t *) data.data(), data.size());
+}
+
+}  // namespace syslog
+}  // namespace esphome

esphome/components/syslog/esphome_syslog.h

@@ -0,0 +1,25 @@
+#pragma once
+#include "esphome/core/component.h"
+#include "esphome/core/helpers.h"
+#include "esphome/core/log.h"
+#include "esphome/components/udp/udp_component.h"
+#include "esphome/components/time/real_time_clock.h"
+
+namespace esphome {
+namespace syslog {
+class Syslog : public Component, public Parented<udp::UDPComponent> {
+ public:
+  Syslog(int level, time::RealTimeClock *time) : log_level_(level), time_(time) {}
+  void setup() override;
+  void set_strip(bool strip) { this->strip_ = strip; }
+  void set_facility(int facility) { this->facility_ = facility; }
+
+ protected:
+  int log_level_;
+  void log_(int level, const char *tag, const char *message) const;
+  time::RealTimeClock *time_;
+  bool strip_{true};
+  int facility_{16};
+};
+}  // namespace syslog
+}  // namespace esphome

tests/components/syslog/common.yaml

@@ -0,0 +1,15 @@
+wifi:
+  ssid: MySSID
+  password: password1
+
+udp:
+  addresses: ["239.0.60.53"]
+
+time:
+  platform: host
+
+syslog:
+  port: 514
+  strip: true
+  level: info
+  facility: 16

tests/components/syslog/test.bk72xx-ard.yaml

@@ -0,0 +1 @@
+<<: !include common.yaml

tests/components/syslog/test.esp32-ard.yaml

@@ -0,0 +1 @@
+<<: !include common.yaml

tests/components/syslog/test.esp32-c3-ard.yaml

@@ -0,0 +1 @@
+<<: !include common.yaml

tests/components/syslog/test.esp32-c3-idf.yaml

@@ -0,0 +1 @@
+<<: !include common.yaml

tests/components/syslog/test.esp32-idf.yaml

@@ -0,0 +1 @@
+<<: !include common.yaml

tests/components/syslog/test.esp8266-ard.yaml

@@ -0,0 +1 @@
+<<: !include common.yaml

tests/components/syslog/test.host.yaml

@@ -0,0 +1,4 @@
+packages:
+  common: !include common.yaml
+
+wifi: !remove

tests/components/syslog/test.rp2040-ard.yaml

@@ -0,0 +1 @@
+<<: !include common.yaml