From cca97ce6a6653df7f4ec71ecd54944cc9a6c4c16 Mon Sep 17 00:00:00 2001 From: Daniel Gustafsson Date: Thu, 21 Sep 2023 13:53:07 +0200 Subject: [PATCH] Allow dbname in pg_basebackup/pg_receivewal connstring As physical replication work at the cluster level and not database level, any dbname in the connection string is ignored. Proxies and middleware used in connecting to the cluster might however need to know the dbname in order to make the correct routing decision for the connection. With this the startup packet will include the dbname parameter. Author: Jelte Fennema-Nio Reviewed-by: Tristen Raab Reviewed-by: Jim Jones Discussion: https://postgr.es/m/CAGECzQTw-dZkVT_RELRzfWRzY714-VaTjoBATYfZq93R8C-auA@mail.gmail.com --- doc/src/sgml/ref/pg_basebackup.sgml | 5 ++++- doc/src/sgml/ref/pg_receivewal.sgml | 7 +++++-- src/bin/pg_basebackup/streamutil.c | 29 ++++++++++++++++++----------- 3 files changed, 27 insertions(+), 14 deletions(-) diff --git a/doc/src/sgml/ref/pg_basebackup.sgml b/doc/src/sgml/ref/pg_basebackup.sgml index d2b8ddd200c..344de921e4b 100644 --- a/doc/src/sgml/ref/pg_basebackup.sgml +++ b/doc/src/sgml/ref/pg_basebackup.sgml @@ -778,7 +778,10 @@ PostgreSQL documentation The option is called --dbname for consistency with other client applications, but because pg_basebackup doesn't connect to any particular database in the cluster, any database - name in the connection string will be ignored. + name in the connection string will be ignored + by PostgreSQL. Middleware, or proxies, used in + connecting to PostgreSQL might however + utilize the value. diff --git a/doc/src/sgml/ref/pg_receivewal.sgml b/doc/src/sgml/ref/pg_receivewal.sgml index cecc7daec97..798b972d3cc 100644 --- a/doc/src/sgml/ref/pg_receivewal.sgml +++ b/doc/src/sgml/ref/pg_receivewal.sgml @@ -316,8 +316,11 @@ PostgreSQL documentation The option is called --dbname for consistency with other client applications, but because pg_receivewal - doesn't connect to any particular database in the cluster, database - name in the connection string will be ignored. + doesn't connect to any particular database in the cluster, any database + name in the connection string will be ignored by + PostgreSQL. Middleware, or proxies, used in + connecting to PostgreSQL might however + utilize the value. diff --git a/src/bin/pg_basebackup/streamutil.c b/src/bin/pg_basebackup/streamutil.c index 75ab9e56f3e..dbd08ab1722 100644 --- a/src/bin/pg_basebackup/streamutil.c +++ b/src/bin/pg_basebackup/streamutil.c @@ -79,9 +79,6 @@ GetConnection(void) /* * Merge the connection info inputs given in form of connection string, * options and default values (dbname=replication, replication=true, etc.) - * Explicitly discard any dbname value in the connection string; - * otherwise, PQconnectdbParams() would interpret that value as being - * itself a connection string. */ i = 0; if (connection_string) @@ -92,18 +89,24 @@ GetConnection(void) for (conn_opt = conn_opts; conn_opt->keyword != NULL; conn_opt++) { - if (conn_opt->val != NULL && conn_opt->val[0] != '\0' && - strcmp(conn_opt->keyword, "dbname") != 0) + if (conn_opt->val != NULL && conn_opt->val[0] != '\0') argcount++; } keywords = pg_malloc0((argcount + 1) * sizeof(*keywords)); values = pg_malloc0((argcount + 1) * sizeof(*values)); + /* + * Set dbname here already, so it can be overridden by a dbname in the + * connection string. + */ + keywords[i] = "dbname"; + values[i] = "replication"; + i++; + for (conn_opt = conn_opts; conn_opt->keyword != NULL; conn_opt++) { - if (conn_opt->val != NULL && conn_opt->val[0] != '\0' && - strcmp(conn_opt->keyword, "dbname") != 0) + if (conn_opt->val != NULL && conn_opt->val[0] != '\0') { keywords[i] = conn_opt->keyword; values[i] = conn_opt->val; @@ -115,11 +118,11 @@ GetConnection(void) { keywords = pg_malloc0((argcount + 1) * sizeof(*keywords)); values = pg_malloc0((argcount + 1) * sizeof(*values)); + keywords[i] = "dbname"; + values[i] = dbname; + i++; } - keywords[i] = "dbname"; - values[i] = dbname == NULL ? "replication" : dbname; - i++; keywords[i] = "replication"; values[i] = dbname == NULL ? "true" : "database"; i++; @@ -171,7 +174,11 @@ GetConnection(void) values[i] = NULL; } - tmpconn = PQconnectdbParams(keywords, values, true); + /* + * Only expand dbname when we did not already parse the argument as a + * connection string ourselves. + */ + tmpconn = PQconnectdbParams(keywords, values, !connection_string); /* * If there is too little memory even to allocate the PGconn object -- 2.39.5