daemon: configuration directory (default ~/.lightning).

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Makefile

@@ -89,6 +89,7 @@ CCAN_OBJS :=					\
 	ccan-str.o				\
 	ccan-take.o				\
 	ccan-tal-grab_file.o			\
+	ccan-tal-path.o				\
 	ccan-tal-str.o				\
 	ccan-tal.o				\
 	ccan-time.o				\
@@ -333,6 +334,8 @@ ccan-tal.o: $(CCANDIR)/ccan/tal/tal.c
 	$(CC) $(CFLAGS) -c -o $@ $<
 ccan-tal-str.o: $(CCANDIR)/ccan/tal/str/str.c
 	$(CC) $(CFLAGS) -c -o $@ $<
+ccan-tal-path.o: $(CCANDIR)/ccan/tal/path/path.c
+	$(CC) $(CFLAGS) -c -o $@ $<
 ccan-tal-grab_file.o: $(CCANDIR)/ccan/tal/grab_file/grab_file.c
 	$(CC) $(CFLAGS) -c -o $@ $<
 ccan-take.o: $(CCANDIR)/ccan/take/take.c

daemon/Makefile

@@ -7,12 +7,14 @@ daemon-wrongdir:
 daemon-all: daemon/lightningd
 
 DAEMON_SRC :=					\
+	daemon/configdir.c			\
 	daemon/lightningd.c			\
 	daemon/log.c				\
 	daemon/pseudorand.c
 DAEMON_OBJS := $(DAEMON_SRC:.c=.o)
 
 DAEMON_HEADERS :=				\
+	daemon/configdir.h			\
 	daemon/lightningd.h			\
 	daemon/log.h				\
 	daemon/pseudorand.h

daemon/configdir.c

@@ -0,0 +1,95 @@
+#include "configdir.h"
+#include "log.h"
+#include <ccan/opt/opt.h>
+#include <ccan/tal/grab_file/grab_file.h>
+#include <ccan/tal/path/path.h>
+#include <ccan/tal/str/str.h>
+#include <errno.h>
+
+static char *default_configdir(const tal_t *ctx)
+{
+	char *path;
+	const char *env = getenv("HOME");
+	if (!env)
+		return ".";
+
+	path = path_join(ctx, env, ".lightning");
+	return path;
+}
+
+void configdir_register_opts(const tal_t *ctx,
+			     char **configdir, char **rpc_filename)
+{
+	*configdir = default_configdir(ctx);
+	*rpc_filename = "lightning-rpc";
+
+	opt_register_early_arg("--lightning-dir", opt_set_charp, opt_show_charp,
+			       configdir,
+			       "working directory: all other files are relative to this");
+
+	opt_register_arg("--rpc-file", opt_set_charp, opt_show_charp,
+			 rpc_filename,
+			 "Set JSON-RPC socket (or /dev/tty)");
+}
+
+/* FIXME: make this nicer! */
+static void config_log_stderr_exit(const char *fmt, ...)
+{
+	char *msg;
+	va_list ap;
+
+	va_start(ap, fmt);
+
+	/* This is the format we expect: mangle it to remove '--'. */
+	if (streq(fmt, "%s: %.*s: %s")) {
+		const char *argv0 = va_arg(ap, const char *);
+		unsigned int len = va_arg(ap, unsigned int);
+		const char *arg = va_arg(ap, const char *);
+		const char *problem = va_arg(ap, const char *);
+
+		msg = tal_fmt(NULL, "%s line %s: %.*s: %s",
+			      argv0, arg+strlen(arg)+1, len-2, arg+2, problem);
+	} else {
+		msg = tal_vfmt(NULL, fmt, ap);
+	}
+	va_end(ap);
+
+	fatal("%s", msg);
+}
+
+/* We turn the config file into cmdline arguments. */
+void opt_parse_from_config(const tal_t *ctx)
+{
+	char *contents, **lines;
+	char **argv;
+	int i, argc;
+
+	contents = grab_file(ctx, "config");
+	/* Doesn't have to exist. */
+	if (!contents) {
+		if (errno != ENOENT)
+			fatal("Opening and reading config: %s",
+			      strerror(errno));
+		return;
+	}
+
+	lines = tal_strsplit(contents, contents, "\r\n", STR_NO_EMPTY);
+
+	/* We have to keep argv around, since opt will point into it */
+	argv = tal_arr(ctx, char *, argc = 1);
+	argv[0] = "lightning config file";
+
+	for (i = 0; i < tal_count(lines) - 1; i++) {
+		if (strstarts(lines[i], "#"))
+			continue;
+		/* Only valid forms are "foo" and "foo=bar" */
+		tal_resize(&argv, argc+1);
+		/* Stash line number after nul. */
+		argv[argc++] = tal_fmt(argv, "--%s%c%u", lines[i], 0, i+1);
+	}
+	tal_resize(&argv, argc+1);
+	argv[argc] = NULL;
+
+	opt_parse(&argc, argv, config_log_stderr_exit);
+	tal_free(contents);
+}

daemon/configdir.h

@@ -0,0 +1,11 @@
+#ifndef LIGHTNING_DAEMON_CONFIGDIR_H
+#define LIGHTNING_DAEMON_CONFIGDIR_H
+#include "config.h"
+#include <ccan/tal/tal.h>
+
+void configdir_register_opts(const tal_t *ctx,
+			     char **config_dir, char **rpc_filename);
+
+void opt_parse_from_config(const tal_t *ctx);
+
+#endif /* LIGHTNING_DAEMON_CONFIGDIR_H */

daemon/lightningd.c

@@ -1,3 +1,4 @@
+#include "configdir.h"
 #include "lightningd.h"
 #include "log.h"
 #include <ccan/err/err.h>
@@ -6,6 +7,7 @@
 #include <ccan/tal/tal.h>
 #include <errno.h>
 #include <string.h>
+#include <sys/stat.h>
 #include <sys/types.h>
 #include <unistd.h>
 #include <version.h>
@@ -54,11 +56,34 @@ int main(int argc, char *argv[])
 	opt_register_logging(state->base_log);
 	opt_register_version();
 
+	configdir_register_opts(state,
+				&state->config_dir, &state->rpc_filename);
+
+	/* Get any configdir options first. */
+	opt_early_parse(argc, argv, opt_log_stderr_exit);
+
+	/* Move to config dir, to save ourselves the hassle of path manip. */
+	if (chdir(state->config_dir) != 0) {
+		log_unusual(state->base_log, "Creating lightningd dir %s"
+			    " (because chdir gave %s)",
+			    state->config_dir, strerror(errno));
+		if (mkdir(state->config_dir, 0700) != 0)
+			fatal("Could not make directory %s: %s",
+			      state->config_dir, strerror(errno));
+		if (chdir(state->config_dir) != 0)
+			fatal("Could not change directory %s: %s",
+			      state->config_dir, strerror(errno));
+	}
+	/* Activate crash log now we're in the right place. */
+	crashlog_activate(state->base_log);
+
+	/* Now look for config file */
+	opt_parse_from_config(state);
+
 	opt_parse(&argc, argv, opt_log_stderr_exit);
 	if (argc != 1)
 		errx(1, "no arguments accepted");
 
-	crashlog_activate(state->base_log);
 	log_info(state->base_log, "Hello world!");
 	tal_free(state);
 	opt_free_table();

daemon/lightningd.h

@@ -9,5 +9,9 @@ struct lightningd_state {
 	struct log_record *log_record;
 	struct log *base_log;
 	FILE *logf;
+
+	/* Our config dir, and rpc file */
+	char *config_dir;
+	char *rpc_filename;
 };
 #endif /* LIGHTNING_DAEMON_LIGHTNING_H */