[PATCH v16 15/15] log: colorize log output

[Stephen Hemminger <stephen@networkplumber.org>]

Like dmesg, colorize the log output (unless redirected to file).
Timestamp is green, the subsystem is in yellow and the message
is red if urgent, boldface if an error, and normal for info and
debug messages.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
 app/test/test_eal_flags.c           |  24 ++++
 doc/guides/prog_guide/log_lib.rst   |  16 ++-
 lib/eal/common/eal_common_options.c |  11 ++
 lib/eal/common/eal_options.h        |   2 +
 lib/log/log.c                       | 165 +++++++++++++++++++++++++++-
 lib/log/log_internal.h              |   5 +
 lib/log/version.map                 |   1 +
 7 files changed, 219 insertions(+), 5 deletions(-)

diff --git a/app/test/test_eal_flags.c b/app/test/test_eal_flags.c
index 08f4866461..c6c05e2e1d 100644
--- a/app/test/test_eal_flags.c
+++ b/app/test/test_eal_flags.c
@@ -1067,6 +1067,18 @@ test_misc_flags(void)
 	const char * const argv25[] = {prgname, prefix, mp_flag,
 				       "--log-timestamp=invalid" };
 
+	/* Try running with --log-color */
+	const char * const argv26[] = {prgname, prefix, mp_flag,
+				       "--log-color" };
+
+	/* Try running with --log-color=never */
+	const char * const argv27[] = {prgname, prefix, mp_flag,
+				       "--log-color=never" };
+
+	/* Try running with --log-color=invalid */
+	const char * const argv28[] = {prgname, prefix, mp_flag,
+				       "--log-color=invalid" };
+
 
 	/* run all tests also applicable to FreeBSD first */
 
@@ -1187,6 +1199,18 @@ test_misc_flags(void)
 		printf("Error - process did run ok with --log-timestamp=invalid parameter\n");
 		goto fail;
 	}
+	if (launch_proc(argv26) != 0) {
+		printf("Error - process did not run ok with --log-color parameter\n");
+		goto fail;
+	}
+	if (launch_proc(argv27) != 0) {
+		printf("Error - process did not run ok with --log-color=none parameter\n");
+		goto fail;
+	}
+	if (launch_proc(argv28) == 0) {
+		printf("Error - process did run ok with --log-timestamp=invalid parameter\n");
+		goto fail;
+	}
 
 
 	rmdir(hugepath_dir3);
diff --git a/doc/guides/prog_guide/log_lib.rst b/doc/guides/prog_guide/log_lib.rst
index abaedc7212..40727ebaae 100644
--- a/doc/guides/prog_guide/log_lib.rst
+++ b/doc/guides/prog_guide/log_lib.rst
@@ -59,6 +59,21 @@ For example::
 
 Within an application, the same result can be got using the ``rte_log_set_level_pattern()`` or ``rte_log_set_level_regex()`` APIs.
 
+Color output
+~~~~~~~~~~~~
+
+The log library will highlight important messages.
+This is controlled by the ``--log-color`` option.
+he optional argument ``when`` can be ``auto``, ``never``, or ``always``.
+The default setting is ``auto`` which enables color when the output to
+``stderr`` is a terminal.
+If the ``when`` argument is omitted, it defaults to ``always``.
+
+For example to turn off all coloring::
+
+	/path/to/app --log-color=none
+
+
 Log timestamp
 ~~~~~~~~~~~~~
 
@@ -101,7 +116,6 @@ option. There are three possible settings for this option:
 If ``--syslog`` option is not specified, then only console (stderr) will be used.
 
 
-
 Using Logging APIs to Generate Log Messages
 -------------------------------------------
 
diff --git a/lib/eal/common/eal_common_options.c b/lib/eal/common/eal_common_options.c
index 9ca7db04aa..5e7ab29ae3 100644
--- a/lib/eal/common/eal_common_options.c
+++ b/lib/eal/common/eal_common_options.c
@@ -75,6 +75,7 @@ eal_long_options[] = {
 	{OPT_LCORES,            1, NULL, OPT_LCORES_NUM           },
 	{OPT_LOG_LEVEL,         1, NULL, OPT_LOG_LEVEL_NUM        },
 	{OPT_LOG_TIMESTAMP,     2, NULL, OPT_LOG_TIMESTAMP_NUM    },
+	{OPT_LOG_COLOR,		2, NULL, OPT_LOG_COLOR_NUM	  },
 	{OPT_TRACE,             1, NULL, OPT_TRACE_NUM            },
 	{OPT_TRACE_DIR,         1, NULL, OPT_TRACE_DIR_NUM        },
 	{OPT_TRACE_BUF_SIZE,    1, NULL, OPT_TRACE_BUF_SIZE_NUM   },
@@ -1618,6 +1619,7 @@ eal_log_level_parse(int argc, char * const argv[])
 		case OPT_LOG_LEVEL_NUM:
 		case OPT_SYSLOG_NUM:
 		case OPT_LOG_TIMESTAMP_NUM:
+		case OPT_LOG_COLOR_NUM:
 			if (eal_parse_common_option(opt, optarg, internal_conf) < 0)
 				return -1;
 			break;
@@ -1862,6 +1864,14 @@ eal_parse_common_option(int opt, const char *optarg,
 		}
 		break;
 
+	case OPT_LOG_COLOR_NUM:
+		if (eal_log_color(optarg) < 0) {
+			EAL_LOG(ERR, "invalid parameters for --"
+				OPT_LOG_COLOR);
+			return -1;
+		}
+		break;
+
 #ifndef RTE_EXEC_ENV_WINDOWS
 	case OPT_TRACE_NUM: {
 		if (eal_trace_args_save(optarg) < 0) {
@@ -2229,6 +2239,7 @@ eal_common_usage(void)
 	       "                      Set specific log level\n"
 	       "  --"OPT_LOG_LEVEL"=help    Show log types and levels\n"
 	       "  --"OPT_LOG_TIMESTAMP"[=<format>]  Timestamp log output\n"
+	       "  --"OPT_LOG_COLOR"[=<when>] Colorize log messages\n"
 #ifndef RTE_EXEC_ENV_WINDOWS
 	       "  --"OPT_TRACE"=<regex-match>\n"
 	       "                      Enable trace based on regular expression trace name.\n"
diff --git a/lib/eal/common/eal_options.h b/lib/eal/common/eal_options.h
index e24c9eca53..5a63c1dd3a 100644
--- a/lib/eal/common/eal_options.h
+++ b/lib/eal/common/eal_options.h
@@ -37,6 +37,8 @@ enum {
 	OPT_LOG_LEVEL_NUM,
 #define OPT_LOG_TIMESTAMP     "log-timestamp"
 	OPT_LOG_TIMESTAMP_NUM,
+#define OPT_LOG_COLOR	      "log-color"
+	OPT_LOG_COLOR_NUM,
 #define OPT_TRACE             "trace"
 	OPT_TRACE_NUM,
 #define OPT_TRACE_DIR         "trace-dir"
diff --git a/lib/log/log.c b/lib/log/log.c
index 650d294120..da14959117 100644
--- a/lib/log/log.c
+++ b/lib/log/log.c
@@ -23,6 +23,7 @@
 #include <sys/un.h>
 #endif
 
+#include <rte_common.h>
 #include <rte_log.h>
 #include <rte_per_lcore.h>
 
@@ -49,6 +50,12 @@ enum eal_log_syslog {
 	EAL_LOG_SYSLOG_BOTH,		/* log to both syslog and stderr */
 };
 
+enum eal_log_color {
+	EAL_LOG_COLOR_AUTO = 0,	/* default */
+	EAL_LOG_COLOR_NEVER,
+	EAL_LOG_COLOR_ALWAYS,
+};
+
 typedef int (*log_print_t)(FILE *f, uint32_t level, const char *fmt, va_list ap);
 static int log_print(FILE *f, uint32_t level, const char *format, va_list ap);
 
@@ -64,6 +71,7 @@ static struct rte_logs {
 #endif
 	log_print_t print_func;
 
+	enum eal_log_color color_mode;
 	enum eal_log_time_format time_format;
 	struct timespec started;   /* when log was initialized */
 	struct timespec previous;  /* when last msg was printed */
@@ -715,6 +723,75 @@ format_timestamp(char *tsbuf, size_t tsbuflen)
 	return 0;
 }
 
+enum color {
+	COLOR_NONE,
+	COLOR_RED,
+	COLOR_GREEN,
+	COLOR_YELLOW,
+	COLOR_BLUE,
+	COLOR_MAGENTA,
+	COLOR_CYAN,
+	COLOR_WHITE,
+	COLOR_BOLD,
+	COLOR_CLEAR
+};
+
+static const char * const color_code[] = {
+	[COLOR_NONE]	= "",
+	[COLOR_RED]	= "\e[31m",
+	[COLOR_GREEN]	= "\e[32m",
+	[COLOR_YELLOW]	= "\e[33m",
+	[COLOR_BLUE]	= "\e[34m",
+	[COLOR_MAGENTA] = "\e[35m",
+	[COLOR_CYAN]    = "\e[36m",
+	[COLOR_WHITE]	= "\e[37m",
+	[COLOR_BOLD]	= "\e[1m",
+	[COLOR_CLEAR]	= "\e[0m",
+};
+
+__rte_format_printf(3, 4)
+static int color_fprintf(FILE *out, enum color color, const char *fmt, ...)
+{
+	va_list args;
+	int ret = 0;
+
+	va_start(args, fmt);
+	ret = fprintf(out, "%s", color_code[color]);
+	ret += vfprintf(out, fmt, args);
+	ret += fprintf(out, "%s", color_code[COLOR_CLEAR]);
+	va_end(args);
+
+	return ret;
+}
+
+static ssize_t
+color_log_write(FILE *f, int level, char *msg)
+{
+	char *cp;
+	ssize_t ret = 0;
+
+	/*
+	 * use convention that first part of message (up to the ':' character)
+	 * is the subsystem id and should be highlighted.
+	 */
+	cp = strchr(msg, ':');
+	if (cp) {
+		/* print first part in yellow */
+		ret = color_fprintf(stderr, COLOR_YELLOW, "%.*s",
+				    (int)(cp - msg + 1), msg);
+		msg = cp + 1;
+	}
+
+	if (level <= 0 || level >= (int)RTE_LOG_INFO)
+		ret += fprintf(f, "%s", msg);
+	else if (level >= (int)RTE_LOG_ERR)
+		ret += color_fprintf(f, COLOR_BOLD, "%s", msg);
+	else
+		ret += color_fprintf(f, COLOR_RED, "%s", msg);
+
+	return ret;
+}
+
 /* default log print function */
 __rte_format_printf(3, 0)
 static int
@@ -930,15 +1007,84 @@ log_open_syslog(const char *id, bool is_terminal)
 }
 #endif
 
+__rte_format_printf(3, 0)
+static int
+color_print(FILE *f, uint32_t level, const char *format, va_list ap)
+{
+	char *buf = NULL;
+	int ret;
+
+	/* need to make temporary buffer for color scan */
+	ret = vasprintf(&buf, format, ap);
+	if (ret > 0) {
+		ret = color_log_write(f, level, buf);
+		free(buf);
+		return ret;
+	}
+
+	/* if vasprintf fails, print without color */
+	return log_print(f, level, format, ap);
+}
+
+__rte_format_printf(3, 0)
+static int
+color_print_with_timestamp(FILE *f, uint32_t level,
+			   const char *format, va_list ap)
+{
+	char tsbuf[128];
+
+	if (format_timestamp(tsbuf, sizeof(tsbuf)) > 0)
+		color_fprintf(f, COLOR_GREEN, "[%s] ", tsbuf);
+
+	return color_print(f, level, format, ap);
+}
+
+/*
+ * Controls whether color is enabled:
+ * modes are:
+ *   always - enable color output regardless
+ *   auto - enable if stderr is a terminal
+ *   never - color output is disabled.
+ */
+int
+eal_log_color(const char *mode)
+{
+	if (mode == NULL || strcmp(mode, "always") == 0)
+		rte_logs.color_mode = EAL_LOG_COLOR_ALWAYS;
+	else if (strcmp(mode, "never") == 0)
+		rte_logs.color_mode = EAL_LOG_COLOR_NEVER;
+	else if (strcmp(mode, "auto") == 0)
+		rte_logs.color_mode = EAL_LOG_COLOR_AUTO;
+	else
+		return -1;
+
+	return 0;
+}
+
+static inline bool
+use_color(bool is_terminal)
+{
+	switch (rte_logs.color_mode) {
+	default:
+	case EAL_LOG_COLOR_NEVER:
+		return false;
+	case EAL_LOG_COLOR_ALWAYS:
+		return true;
+	case EAL_LOG_COLOR_AUTO:
+		return is_terminal;
+	}
+
+}
+
 /* Choose how log output is directed */
 static void
 log_output_selection(const char *id)
 {
+	bool is_terminal = isatty(STDERR_FILENO);
+
 #ifdef RTE_EXEC_ENV_WINDOWS
 	RTE_SET_USED(id);
 #else
-	bool is_terminal = isatty(STDERR_FILENO);
-
 	/* If stderr is redirected to systemd journal then upgrade */
 	if (!is_terminal && is_journal(STDERR_FILENO)) {
 		int jfd = open_journal(id);
@@ -957,8 +1103,19 @@ log_output_selection(const char *id)
 		return;
 	}
 #endif
-	if (rte_logs.time_format != EAL_LOG_TIMESTAMP_NONE)
-		rte_logs.print_func = log_print_with_timestamp;
+
+	if (use_color(is_terminal)) {
+		if (rte_logs.time_format == EAL_LOG_TIMESTAMP_NONE)
+			rte_logs.print_func = color_print;
+		else
+			rte_logs.print_func = color_print_with_timestamp;
+	} else {
+		if (rte_logs.time_format == EAL_LOG_TIMESTAMP_NONE)
+			rte_logs.print_func = log_print;
+		else
+			rte_logs.print_func = log_print_with_timestamp;
+	}
+
 }
 
 /*
diff --git a/lib/log/log_internal.h b/lib/log/log_internal.h
index 7c7d44eed2..525e1397fd 100644
--- a/lib/log/log_internal.h
+++ b/lib/log/log_internal.h
@@ -47,5 +47,10 @@ void rte_eal_log_cleanup(void);
 __rte_internal
 int eal_log_timestamp(const char *fmt);
 
+/*
+ * Enable or disable color in log messages
+ */
+__rte_internal
+int eal_log_color(const char *mode);
 
 #endif /* LOG_INTERNAL_H */
diff --git a/lib/log/version.map b/lib/log/version.map
index 14d6681a5f..7fa79b20ff 100644
--- a/lib/log/version.map
+++ b/lib/log/version.map
@@ -25,6 +25,7 @@ DPDK_24 {
 INTERNAL {
 	global:
 
+	eal_log_color;
 	eal_log_init;
 	eal_log_level2str;
 	eal_log_save_pattern;
-- 
2.43.0