/* * repmgr-action-standby.c * * Implements standby actions for the repmgr command line utility * * Copyright (c) 2ndQuadrant, 2010-2017 */ #include "repmgr.h" #include "dirutil.h" #include "compat.h" #include "repmgr-client-global.h" #include "repmgr-action-standby.h" static PGconn *primary_conn = NULL; static PGconn *source_conn = NULL; static int server_version_num = UNKNOWN_SERVER_VERSION_NUM; static char local_data_directory[MAXPGPATH]; static bool local_data_directory_provided = false; static bool upstream_record_found = false; static int upstream_node_id = UNKNOWN_NODE_ID; static char upstream_data_directory[MAXPGPATH]; static t_conninfo_param_list recovery_conninfo; static char recovery_conninfo_str[MAXLEN]; static t_configfile_list config_files = T_CONFIGFILE_LIST_INITIALIZER; static standy_clone_mode mode; /* used by barman mode */ static char local_repmgr_tmp_directory[MAXPGPATH]; static void check_barman_config(void); static void check_source_server(void); static void check_source_server_via_barman(void); static void initialise_direct_clone(void); static void config_file_list_init(t_configfile_list *list, int max_size); static void config_file_list_add(t_configfile_list *list, const char *file, const char *filename, bool in_data_dir); static void get_barman_property(char *dst, char *name, char *local_repmgr_directory); static char *make_barman_ssh_command(char *buf); void do_standby_clone(void) { /* * conninfo params for the actual upstream node (which might be different * to the node we're cloning from) to write to recovery.conf */ /* * detecting the cloning mode */ mode = get_standby_clone_mode(); /* * In rsync mode, we need to check the SSH connection early */ if (mode == rsync) { int r; r = test_ssh_connection(runtime_options.host, runtime_options.remote_user); if (r != 0) { log_error(_("remote host %s is not reachable via SSH"), runtime_options.host); exit(ERR_BAD_SSH); } } /* * If dest_dir (-D/--pgdata) was provided, this will become the new data * directory (otherwise repmgr will default to using the same directory * path as on the source host). * * Note that barman mode requires -D/--pgdata. * * If -D/--pgdata is not supplied, and we're not cloning from barman, * the source host's data directory will be fetched later, after * we've connected to it. */ if (runtime_options.data_dir[0]) { local_data_directory_provided = true; log_notice(_("destination directory '%s' provided"), runtime_options.data_dir); } else if (mode == barman) { log_error(_("Barman mode requires a data directory")); log_hint(_("use -D/--pgdata to explicitly specify a data directory")); exit(ERR_BAD_CONFIG); } /* Sanity-check barman connection and installation */ if (mode == barman) { /* this will exit with ERR_BARMAN if problems found */ check_barman_config(); } /* * target directory (-D/--pgdata) provided - use that as new data directory * (useful when executing backup on local machine only or creating the backup * in a different local directory when backup source is a remote host) */ if (local_data_directory_provided == true) { strncpy(local_data_directory, runtime_options.data_dir, MAXPGPATH); } /* * Initialise list of conninfo parameters which will later be used * to create the `primary_conninfo` string in recovery.conf . * * We'll initialise it with the default values as seen by libpq, * and overwrite them with the host settings specified on the command * line. As it's possible the standby will be cloned from a node different * to its intended upstream, we'll later attempt to fetch the * upstream node record and overwrite the values set here with * those from the upstream node record (excluding that record's * application_name) */ initialize_conninfo_params(&recovery_conninfo, true); copy_conninfo_params(&recovery_conninfo, &source_conninfo); /* * If application_name is set in repmgr.conf's conninfo parameter, use * this value (if the source host was provided as a conninfo string, any * application_name values set there will be overridden; we assume the only * reason to pass an application_name via the command line is in the * rare corner case where a user wishes to clone a server without * providing repmgr.conf) */ if (strlen(config_file_options.conninfo)) { char application_name[MAXLEN] = ""; get_conninfo_value(config_file_options.conninfo, "application_name", application_name); if (strlen(application_name)) { param_set(&recovery_conninfo, "application_name", application_name); } } /* * --upstream-conninfo supplied, which we interpret to imply * --no-upstream-connection as well - the use case for this option is when * the upstream is not available, so no point in checking for it. */ if (*runtime_options.upstream_conninfo) runtime_options.no_upstream_connection = true; /* By default attempt to connect to the source server */ if (runtime_options.no_upstream_connection == false) { check_source_server(); } if (mode == barman && PQstatus(source_conn) != CONNECTION_OK) { /* * Here we don't have a connection to the upstream node, and are executing * in Barman mode - we can try and connect via the Barman server to extract * the upstream node's conninfo string. * * To do this we need to extract Barman's conninfo string, replace the database * name with the repmgr one (they could well be different) and remotely execute * psql. */ check_source_server_via_barman(); } if (upstream_record_found == true) { /* parse returned upstream conninfo string to recovery primary_conninfo params*/ char *errmsg = NULL; bool parse_success; log_verbose(LOG_DEBUG, "parsing upstream conninfo string \"%s\"", recovery_conninfo_str); /* parse_conninfo_string() here will remove the upstream's `application_name`, if set */ parse_success = parse_conninfo_string(recovery_conninfo_str, &recovery_conninfo, errmsg, true); if (parse_success == false) { log_error(_("unable to parse conninfo string \"%s\" for upstream node:\n%s"), recovery_conninfo_str, errmsg); PQfinish(source_conn); exit(ERR_BAD_CONFIG); } } else { /* * If no upstream node record found, we'll abort with an error here, * unless -F/--force is used, in which case we'll use the parameters * provided on the command line (and assume the user knows what they're * doing). */ if (!runtime_options.force) { log_error(_("no record found for upstream node (upstream_node_id: %i)"), upstream_node_id); log_hint(_("use -F/--force to create \"primary_conninfo\" based on command-line parameters")); PQfinish(source_conn); exit(ERR_BAD_CONFIG); } } /* If --replication-user was set, use that value for the primary_conninfo user */ if (*runtime_options.replication_user) { param_set(&recovery_conninfo, "user", runtime_options.replication_user); } if (mode != barman) { initialise_direct_clone(); } } void check_barman_config(void) { char datadir_list_filename[MAXLEN]; char barman_command_buf[MAXLEN] = ""; char command[MAXLEN]; bool command_ok; /* * Check that there is at least one valid backup */ log_info(_("connecting to Barman server to verify backup for %s"), config_file_options.barman_server); maxlen_snprintf(command, "%s show-backup %s latest > /dev/null", make_barman_ssh_command(barman_command_buf), config_file_options.barman_server); command_ok = local_command(command, NULL); if (command_ok == false) { log_error(_("no valid backup for server %s was found in the Barman catalogue"), config_file_options.barman_server); log_hint(_("refer to the Barman documentation for more information\n")); exit(ERR_BARMAN); } /* * Create the local repmgr subdirectory */ maxlen_snprintf(local_repmgr_tmp_directory, "%s/repmgr", local_data_directory); maxlen_snprintf(datadir_list_filename, "%s/data.txt", local_repmgr_tmp_directory); if (!create_pg_dir(local_data_directory, runtime_options.force)) { log_error(_("unable to use directory %s"), local_data_directory); log_hint(_("use -F/--force option to force this directory to be overwritten\n")); exit(ERR_BAD_CONFIG); } if (!create_pg_dir(local_repmgr_tmp_directory, runtime_options.force)) { log_error(_("unable to create directory \"%s\""), local_repmgr_tmp_directory); exit(ERR_BAD_CONFIG); } /* * Fetch server parameters from Barman */ log_info(_("connecting to Barman server to fetch server parameters")); maxlen_snprintf(command, "%s show-server %s > %s/show-server.txt", make_barman_ssh_command(barman_command_buf), config_file_options.barman_server, local_repmgr_tmp_directory); command_ok = local_command(command, NULL); if (command_ok == false) { log_error(_("unable to fetch server parameters from Barman server")); exit(ERR_BARMAN); } } static void check_source_server() { char cluster_size[MAXLEN]; t_node_info node_record = T_NODE_INFO_INITIALIZER; int query_result; t_extension_status extension_status; /* Attempt to connect to the upstream server to verify its configuration */ log_info(_("connecting to upstream node")); source_conn = establish_db_connection_by_params((const char**)source_conninfo.keywords, (const char**)source_conninfo.values, false); /* * Unless in barman mode, exit with an error; * establish_db_connection_by_params() will have already logged an error message */ if (PQstatus(source_conn) != CONNECTION_OK) { PQfinish(source_conn); if (mode == barman) return; else exit(ERR_DB_CON); } /* * If a connection was established, perform some sanity checks on the * provided upstream connection */ /* Verify that upstream node is a supported server version */ log_verbose(LOG_INFO, _("connected to source node, checking its state")); server_version_num = check_server_version(source_conn, "master", true, NULL); check_upstream_config(source_conn, server_version_num, true); if (get_cluster_size(source_conn, cluster_size) == false) exit(ERR_DB_QUERY); log_info(_("successfully connected to source node")); log_detail(_("current installation size is %s"), cluster_size); /* * If --recovery-min-apply-delay was passed, check that * we're connected to PostgreSQL 9.4 or later */ // XXX should this be a config file parameter? if (*runtime_options.recovery_min_apply_delay) { if (server_version_num < 90400) { log_error(_("PostgreSQL 9.4 or greater required for --recovery-min-apply-delay\n")); PQfinish(source_conn); exit(ERR_BAD_CONFIG); } } /* * If the upstream node is a standby, try to connect to the primary too so we * can write an event record */ if (is_standby(source_conn)) { primary_conn = get_master_connection(source_conn, NULL, NULL); // XXX check this worked? } else { primary_conn = source_conn; } /* * Sanity-check that the master node has a repmgr schema - if not * present, fail with an error unless -F/--force is used (to enable * repmgr to be used as a standalone clone tool) */ extension_status = get_repmgr_extension_status(primary_conn); if (extension_status != REPMGR_INSTALLED) { if (!runtime_options.force) { /* schema doesn't exist */ log_error(_("repmgr extension not found on source node")); log_hint(_("check that the upstream server is part of a repmgr cluster")); PQfinish(source_conn); exit(ERR_BAD_CONFIG); } log_warning(_("repmgr extension not found on source node")); } /* Fetch the source's data directory */ if (get_pg_setting(source_conn, "data_directory", upstream_data_directory) == false) { log_error(_("unable to retrieve source node's data directory")); log_hint(_("STANDBY CLONE must be run as a database superuser")); PQfinish(source_conn); exit(ERR_BAD_CONFIG); } /* * If no target data directory was explicitly provided, we'll default to * the source host's data directory. */ if (local_data_directory_provided == false) { strncpy(local_data_directory, upstream_data_directory, MAXPGPATH); log_notice(_("setting data directory to: \"%s\""), local_data_directory); log_hint(_("use -D/--pgdata to explicitly specify a data directory")); } /* * Copy the source connection so that we have some default values, * particularly stuff like passwords extracted from PGPASSFILE; * these will be overridden from the upstream conninfo, if provided. * * XXX only allow passwords if --use-conninfo-password */ conn_to_param_list(source_conn, &recovery_conninfo); /* * Attempt to find the upstream node record */ if (config_file_options.upstream_node_id == NO_UPSTREAM_NODE) upstream_node_id = get_master_node_id(source_conn); else upstream_node_id = config_file_options.upstream_node_id; query_result = get_node_record(source_conn, upstream_node_id, &node_record); if (query_result) { upstream_record_found = true; strncpy(recovery_conninfo_str, node_record.conninfo, MAXLEN); } /* * check that there's no existing node record with the same name but * different ID */ query_result = get_node_record_by_name(source_conn, config_file_options.node_name, &node_record); if (query_result) { log_error(_("another node (node_id: %i) already exists with node_name \"%s\""), node_record.node_id, config_file_options.node_name); PQfinish(source_conn); exit(ERR_BAD_CONFIG); } } static void check_source_server_via_barman() { char buf[MAXLEN]; char barman_conninfo_str[MAXLEN]; t_conninfo_param_list barman_conninfo; char *errmsg = NULL; bool parse_success, command_success; char where_condition[MAXLEN]; PQExpBufferData command_output; PQExpBufferData repmgr_conninfo_buf; int c; get_barman_property(barman_conninfo_str, "conninfo", local_repmgr_tmp_directory); initialize_conninfo_params(&barman_conninfo, false); /* parse_conninfo_string() here will remove the upstream's `application_name`, if set */ parse_success = parse_conninfo_string(barman_conninfo_str, &barman_conninfo, errmsg, true); if (parse_success == false) { log_error(_("Unable to parse barman conninfo string \"%s\":\n%s"), barman_conninfo_str, errmsg); exit(ERR_BARMAN); } /* Overwrite database name in the parsed parameter list */ param_set(&barman_conninfo, "dbname", runtime_options.dbname); /* Rebuild the Barman conninfo string */ initPQExpBuffer(&repmgr_conninfo_buf); for (c = 0; c < barman_conninfo.size && barman_conninfo.keywords[c] != NULL; c++) { if (repmgr_conninfo_buf.len != 0) appendPQExpBufferChar(&repmgr_conninfo_buf, ' '); appendPQExpBuffer(&repmgr_conninfo_buf, "%s=", barman_conninfo.keywords[c]); appendConnStrVal(&repmgr_conninfo_buf, barman_conninfo.values[c]); } log_verbose(LOG_DEBUG, "repmgr database conninfo string on barman server: %s", repmgr_conninfo_buf.data); // XXX check this works in all cases maxlen_snprintf(where_condition, "node_id=%i", upstream_node_id); initPQExpBuffer(&command_output); maxlen_snprintf(buf, "ssh %s \"psql -Aqt \\\"%s\\\" -c \\\"" " SELECT conninfo" " FROM repmgr.nodes" " WHERE %s" " AND active IS TRUE" "\\\"\"", config_file_options.barman_host, repmgr_conninfo_buf.data, where_condition); termPQExpBuffer(&repmgr_conninfo_buf); command_success = local_command(buf, &command_output); if (command_success == false) { log_error(_("unable to execute database query via Barman server")); exit(ERR_BARMAN); } maxlen_snprintf(recovery_conninfo_str, "%s", command_output.data); string_remove_trailing_newlines(recovery_conninfo_str); upstream_record_found = true; log_verbose(LOG_DEBUG, "upstream node conninfo string extracted via barman server: %s", recovery_conninfo_str); termPQExpBuffer(&command_output); } /* * In pg_basebackup/rsync modes, configure the target data directory * if necessary, and fetch information about tablespaces and configuration * files. */ static void initialise_direct_clone(void) { PGresult *res; int i; PQExpBufferData query; /* * Check the destination data directory can be used * (in Barman mode, this directory will already have been created) */ if (!create_pg_dir(local_data_directory, runtime_options.force)) { log_error(_("unable to use directory %s ..."), local_data_directory); log_hint(_("use -F/--force to force this directory to be overwritten\n")); exit(ERR_BAD_CONFIG); } /* * Check that tablespaces named in any `tablespace_mapping` configuration * file parameters exist. * * pg_basebackup doesn't verify mappings, so any errors will not be caught. * We'll do that here as a value-added service. * * -T/--tablespace-mapping is not available as a pg_basebackup option for * PostgreSQL 9.3 - we can only handle that with rsync, so if `--rsync-only` * not set, fail with an error */ if (config_file_options.tablespace_mapping.head != NULL) { TablespaceListCell *cell; if (server_version_num < 90400 && !runtime_options.rsync_only) { log_error(_("in PostgreSQL 9.3, tablespace mapping can only be used in conjunction with --rsync-only")); PQfinish(source_conn); exit(ERR_BAD_CONFIG); } for (cell = config_file_options.tablespace_mapping.head; cell; cell = cell->next) { initPQExpBuffer(&query); // XXX escape value appendPQExpBuffer(&query, "SELECT spcname " " FROM pg_catalog.pg_tablespace " " WHERE pg_tablespace_location(oid) = '%s'", cell->old_dir); res = PQexec(source_conn, query.data); termPQExpBuffer(&query); if (PQresultStatus(res) != PGRES_TUPLES_OK) { log_error(_("unable to execute tablespace query:\n %s"), PQerrorMessage(source_conn)); PQclear(res); PQfinish(source_conn); exit(ERR_BAD_CONFIG); } /* TODO: collate errors and output at end of loop */ if (PQntuples(res) == 0) { log_error(_("no tablespace matching path '%s' found\n"), cell->old_dir); PQclear(res); PQfinish(source_conn); exit(ERR_BAD_CONFIG); } } } /* * Obtain configuration file locations * We'll check to see whether the configuration files are in the data * directory - if not we'll have to copy them via SSH, if copying * requested. * * XXX: if configuration files are symlinks to targets outside the data * directory, they won't be copied by pg_basebackup, but we can't tell * this from the below query; we'll probably need to add a check for their * presence and if missing force copy by SSH */ initPQExpBuffer(&query); appendPQExpBuffer(&query, " WITH dd AS ( " " SELECT setting AS data_directory" " FROM pg_catalog.pg_settings " " WHERE name = 'data_directory' " " ) " " SELECT DISTINCT(sourcefile), " " regexp_replace(sourcefile, '^.*\\/', '') AS filename, " " sourcefile ~ ('^' || dd.data_directory) AS in_data_dir " " FROM dd, pg_catalog.pg_settings ps " " WHERE sourcefile IS NOT NULL " " ORDER BY 1 "); log_debug("standby clone: %s", query.data); res = PQexec(source_conn, query.data); termPQExpBuffer(&query); if (PQresultStatus(res) != PGRES_TUPLES_OK) { log_error(_("unable to retrieve configuration file locations:\n %s"), PQerrorMessage(source_conn)); PQclear(res); PQfinish(source_conn); exit(ERR_BAD_CONFIG); } /* * allocate memory for config file array - number of rows returned from * above query + 2 for pg_hba.conf, pg_ident.conf */ config_file_list_init(&config_files, PQntuples(res) + 2); for (i = 0; i < PQntuples(res); i++) { config_file_list_add(&config_files, PQgetvalue(res, i, 0), PQgetvalue(res, i, 1), strcmp(PQgetvalue(res, i, 2), "t") == 1 ? true : false); } PQclear(res); /* Fetch locations of pg_hba.conf and pg_ident.conf */ initPQExpBuffer(&query); appendPQExpBuffer(&query, " WITH dd AS ( " " SELECT setting AS data_directory" " FROM pg_catalog.pg_settings " " WHERE name = 'data_directory' " " ) " " SELECT ps.setting, " " regexp_replace(setting, '^.*\\/', '') AS filename, " " ps.setting ~ ('^' || dd.data_directory) AS in_data_dir " " FROM dd, pg_catalog.pg_settings ps " " WHERE ps.name IN ('hba_file', 'ident_file') " " ORDER BY 1 "); log_debug("standby clone: %s", query.data); res = PQexec(source_conn, query.data); termPQExpBuffer(&query); if (PQresultStatus(res) != PGRES_TUPLES_OK) { log_error(_("unable to retrieve configuration file locations: %s\n"), PQerrorMessage(source_conn)); PQclear(res); PQfinish(source_conn); exit(ERR_BAD_CONFIG); } for (i = 0; i < PQntuples(res); i++) { config_file_list_add(&config_files, PQgetvalue(res, i, 0), PQgetvalue(res, i, 1), strcmp(PQgetvalue(res, i, 2), "t") == 1 ? true : false); } PQclear(res); } static char * make_barman_ssh_command(char *buf) { static char config_opt[MAXLEN] = ""; if (strlen(config_file_options.barman_config)) maxlen_snprintf(config_opt, " --config=%s", config_file_options.barman_config); maxlen_snprintf(buf, "ssh %s barman%s", config_file_options.barman_server, config_opt); return buf; } void get_barman_property(char *dst, char *name, char *local_repmgr_directory) { PQExpBufferData command_output; char buf[MAXLEN]; char command[MAXLEN]; char *p; initPQExpBuffer(&command_output); maxlen_snprintf(command, "grep \"^\t%s:\" %s/show-server.txt", name, local_repmgr_tmp_directory); (void)local_command(command, &command_output); maxlen_snprintf(buf, "\t%s: ", name); p = string_skip_prefix(buf, command_output.data); if (p == NULL) { log_error("unexpected output from Barman: %s", command_output.data); exit(ERR_INTERNAL); } strncpy(dst, p, MAXLEN); string_remove_trailing_newlines(dst); termPQExpBuffer(&command_output); } static void config_file_list_init(t_configfile_list *list, int max_size) { list->size = max_size; list->entries = 0; list->files = pg_malloc0(sizeof(t_configfile_info *) * max_size); } static void config_file_list_add(t_configfile_list *list, const char *file, const char *filename, bool in_data_dir) { /* Failsafe to prevent entries being added beyond the end */ if (list->entries == list->size) return; list->files[list->entries] = pg_malloc0(sizeof(t_configfile_info)); strncpy(list->files[list->entries]->filepath, file, MAXPGPATH); canonicalize_path(list->files[list->entries]->filepath); strncpy(list->files[list->entries]->filename, filename, MAXPGPATH); list->files[list->entries]->in_data_directory = in_data_dir; list->entries ++; }