bkpr: Add an option to set the database to something else (postgres)

`lightningd` has an option --wallet that lets you supply a database dsn
string to connect to a sqlite3/postgres database that's hosted/stored
elsewhere.

This adds the `--bookkeeper-db` option which does the same, except for
the bookkeeping data for a node!

Note that the default is to go in the `lightning-dir` in a database
called `accounts.sqlite3`

doc/lightning-listconfigs.7

@@ -81,6 +81,8 @@ On success, an object is returned, containing:
 .IP \[bu]
 \fBbookkeeper-dir\fR (string, optional): \fBbookkeeper-dir\fR field from config or cmdline, or default
 .IP \[bu]
+\fBbookkeeper-db\fR (string, optional): \fBbookkeeper-db\fR field from config or cmdline, or default
+.IP \[bu]
 \fBalways-use-proxy\fR (boolean, optional): \fBalways-use-proxy\fR field from config or cmdline, or default
 .IP \[bu]
 \fBdaemon\fR (boolean, optional): \fBdaemon\fR field from config or cmdline, or default
@@ -286,4 +288,4 @@ Vincenzo Palazzo \fI<vincenzo.palazzo@protonmail.com\fR> wrote the initial versi
 
 Main web site: \fIhttps://github.com/ElementsProject/lightning\fR
 
-\" SHA256STAMP:b1148d7469f7bac293482be6f501031e4cac02f9bc113cf372a31747eb7a6055
+\" SHA256STAMP:acf490bbc9c764f67bf72de7383ea05422ce892dbf70de5ba8918fad15900bd8

doc/lightning-listconfigs.7.md

@@ -51,6 +51,7 @@ On success, an object is returned, containing:
 - **disable-plugin** (array of strings, optional):
   - `disable-plugin` field from config or cmdline
 - **bookkeeper-dir** (string, optional): `bookkeeper-dir` field from config or cmdline, or default
+- **bookkeeper-db** (string, optional): `bookkeeper-db` field from config or cmdline, or default
 - **always-use-proxy** (boolean, optional): `always-use-proxy` field from config or cmdline, or default
 - **daemon** (boolean, optional): `daemon` field from config or cmdline, or default
 - **wallet** (string, optional): `wallet` field from config or cmdline, or default
@@ -213,4 +214,4 @@ RESOURCES
 ---------
 
 Main web site: <https://github.com/ElementsProject/lightning>
-[comment]: # ( SHA256STAMP:4a4cacd309d9593b45cb27563c25d9d3df7df8aef2b281145abeee27eae57fa9)
+[comment]: # ( SHA256STAMP:999502771ada48f32011ea4df2443a2a3385d27377d8e55ec82cf283f9acd0a6)

doc/lightningd-config.5.md

@@ -221,6 +221,13 @@ automatically by `lightningd`.
 Directory to keep the accounts.sqlite3 database file in.
 Defaults to lightning-dir.
 
+ **bookkeeper-db**=*DSN*
+Identify the location of the bookkeeper data. This is a fully qualified data source
+name, including a scheme such as `sqlite3` or `postgres` followed by the
+connection parameters.
+Defaults to `sqlite3://accounts.sqlite3` in the `bookkeeper-dir`.
+
+
  **encrypted-hsm**
 If set, you will be prompted to enter a password used to encrypt the `hsm_secret`.
 Note that once you encrypt the `hsm_secret` this option will be mandatory for

doc/schemas/listconfigs.schema.json

@@ -97,6 +97,10 @@
       "type": "string",
       "description": "`bookkeeper-dir` field from config or cmdline, or default"
     },
+    "bookkeeper-db": {
+      "type": "string",
+      "description": "`bookkeeper-db` field from config or cmdline, or default"
+    },
     "always-use-proxy": {
       "type": "boolean",
       "description": "`always-use-proxy` field from config or cmdline, or default"

plugins/bkpr/bookkeeper.c

@@ -34,7 +34,7 @@
 /* The database that we store all the accounting data in */
 static struct db *db ;
 
-static char *db_dsn = "sqlite3://accounts.sqlite3";
+static char *db_dsn;
 static char *datadir;
 
 static struct fee_sum *find_sum_for_txid(struct fee_sum **sums,
@@ -1780,7 +1780,14 @@ static const char *init(struct plugin *p, const char *b, const jsmntok_t *t)
 				   "Unable to switch to 'bookkeeper-dir'=%s",
 				   datadir);
 	}
+
+	/* No user suppled db_dsn, set one up here */
+	if (!db_dsn)
+		db_dsn = tal_fmt(NULL, "sqlite3://accounts.sqlite3");
+
+	plugin_log(p, LOG_DBG, "Setting up database at %s", db_dsn);
 	db = notleak(db_setup(p, p, db_dsn));
+	db_dsn = tal_free(db_dsn);
 
 	return NULL;
 }
@@ -1791,6 +1798,8 @@ int main(int argc, char *argv[])
 
 	/* No datadir is default */
 	datadir = NULL;
+	db_dsn = NULL;
+
 	plugin_main(argv, init, PLUGIN_STATIC, true, NULL,
 		    commands, ARRAY_SIZE(commands),
 		    notifs, ARRAY_SIZE(notifs),
@@ -1800,6 +1809,11 @@ int main(int argc, char *argv[])
 				  "string",
 				  "Location for bookkeeper records.",
 				  charp_option, &datadir),
+		    plugin_option("bookkeeper-db",
+				  "string",
+				  "Location of the bookkeeper database",
+				  charp_option, &db_dsn),
 		    NULL);
+
 	return 0;
 }