tools: add 'lvm lastlog' command for interactive query and display of last command's log

If we're running in lvm shell, we can keep last command's log report
for further query with possible different selection criteria for easy
log lookup.

8 files changed, 70 insertions, 3 deletions

diff --git a/WHATS_NEW b/WHATS_NEW
index f800ecac3..6f6e9e843 100644
--- a/WHATS_NEW
+++ b/WHATS_NEW
@@ -1,5 +1,6 @@
 Version 2.02.158 - 
 =================================
+  Add lvm lastlog command for query and display of last cmd's log in lvm shell.
   Report per-object return codes via cmd log while processing multiple objects.
   Annotate processing code with log report hooks for per-object command log.
   Also pass common printed messages (besides warnings and errors) to log report.
diff --git a/lib/commands/toolcontext.c b/lib/commands/toolcontext.c
index 076f48ddb..75f19c9f4 100644
--- a/lib/commands/toolcontext.c
+++ b/lib/commands/toolcontext.c
@@ -2247,6 +2247,9 @@ void destroy_toolcontext(struct cmd_context *cmd)
 	if (cmd->cft_def_hash)
 		dm_hash_destroy(cmd->cft_def_hash);
 
+	if (cmd->log_rh)
+		dm_report_free(cmd->log_rh);
+
 	if (cmd->libmem)
 		dm_pool_destroy(cmd->libmem);
 
diff --git a/lib/commands/toolcontext.h b/lib/commands/toolcontext.h
index c04455c9f..ee849b5e4 100644
--- a/lib/commands/toolcontext.h
+++ b/lib/commands/toolcontext.h
@@ -186,6 +186,11 @@ struct cmd_context {
 	char proc_dir[PATH_MAX];
 
 	/*
+	 * Command log reporting.
+	 */
+	struct dm_report *log_rh;		/* keep log report of last cmd for further queries if cmd line is interactive (e.g. lvm shell) */
+
+	/*
 	 * Buffers.
 	 */
 	char display_buffer[NAME_LEN * 10];	/* ring buffer for upto 10 longest vg/lv names */
diff --git a/tools/Makefile.in b/tools/Makefile.in
index bb2917602..8dfac7fd7 100644
--- a/tools/Makefile.in
+++ b/tools/Makefile.in
@@ -168,7 +168,7 @@ liblvm2cmd.$(LIB_SUFFIX).$(LIB_VERSION): liblvm2cmd.$(LIB_SUFFIX)
 
 .commands: $(srcdir)/commands.h $(srcdir)/cmdnames.h Makefile
 	$(CC) -E -P $(srcdir)/cmdnames.h 2> /dev/null | \
-		egrep -v '^ *(|#.*|config|devtypes|dumpconfig|formats|fullreport|help|lvpoll|pvdata|segtypes|systemid|tags|version) *$$' > .commands
+		egrep -v '^ *(|#.*|config|devtypes|dumpconfig|formats|fullreport|help|lastlog|lvpoll|pvdata|segtypes|systemid|tags|version) *$$' > .commands
 
 ifneq ("$(CFLOW_CMD)", "")
 CFLOW_SOURCES = $(addprefix $(srcdir)/, $(SOURCES))
diff --git a/tools/commands.h b/tools/commands.h
index 3f0fff56b..d54a50c15 100644
--- a/tools/commands.h
+++ b/tools/commands.h
@@ -174,6 +174,15 @@ xx(fullreport,
    rows_ARG, select_ARG, separator_ARG, shared_ARG, sort_ARG, trustcache_ARG,
    unbuffered_ARG, units_ARG, unquoted_ARG)
 
+xx(lastlog,
+   "Display last command's log report",
+   PERMITTED_READ_ONLY | NO_METADATA_PROCESSING,
+   "log\n"
+   "\t[--reportformat {json}]\n"
+   "\t[-S|--select Selection]\n",
+
+   reportformat_ARG, select_ARG)
+
 xx(lvchange,
    "Change the attributes of logical volume(s)",
    CACHE_VGMETADATA | PERMITTED_READ_ONLY,
diff --git a/tools/lvm.c b/tools/lvm.c
index 18e349068..62cc14190 100644
--- a/tools/lvm.c
+++ b/tools/lvm.c
@@ -235,6 +235,12 @@ int lvm_shell(struct cmd_context *cmd, struct cmdline_context *cmdline)
 			break;
 		}
 
+		if (cmd->log_rh && strcmp(argv[0], "lastlog")) {
+			/* drop old log report */
+			dm_report_free(cmd->log_rh);
+			cmd->log_rh = NULL;
+		}
+
 		ret = lvm_run_command(cmd, argc, argv);
 		if (ret == ENO_SUCH_CMD)
 			log_error("No such command '%s'.  Try 'help'.",
diff --git a/tools/reporter.c b/tools/reporter.c
index 3df4baca5..c732d0ef9 100644
--- a/tools/reporter.c
+++ b/tools/reporter.c
@@ -1497,3 +1497,38 @@ bad:
 		dm_report_free(tmp_log_rh);
 	return 0;
 }
+
+int lastlog(struct cmd_context *cmd, int argc, char **argv)
+{
+	static report_idx_t expected_idxs[] = {REPORT_IDX_SINGLE, REPORT_IDX_LOG, REPORT_IDX_NULL};
+	struct dm_report_group *report_group = NULL;
+	const char *selection = NULL;
+	int r = ECMD_FAILED;
+
+	if (!cmd->log_rh) {
+		log_error("No log report stored.");
+		goto out;
+	}
+
+	if (!report_format_init(cmd, NULL, &report_group, &cmd->log_rh, NULL))
+		goto_out;
+
+	if (arg_count(cmd, select_ARG) &&
+	    !_do_report_get_selection(cmd, NULL, NULL, expected_idxs, &selection))
+		goto_out;
+
+	if (!dm_report_set_selection(cmd->log_rh, selection)) {
+		log_error("Failed to set selection for log report.");
+		goto out;
+	}
+
+	if (!dm_report_output(cmd->log_rh) ||
+	    !dm_report_group_pop(report_group))
+		goto_out;
+
+	r = ECMD_PROCESSED;
+out:
+	if (!dm_report_group_destroy(report_group))
+		stack;
+	return r;
+}
diff --git a/tools/toollib.c b/tools/toollib.c
index e044cb42d..41ef5499c 100644
--- a/tools/toollib.c
+++ b/tools/toollib.c
@@ -1778,8 +1778,16 @@ void destroy_processing_handle(struct cmd_context *cmd, struct processing_handle
 
 		if (!dm_report_group_destroy(handle->report_group))
 			stack;
-		if (handle->log_rh)
-			dm_report_free(handle->log_rh);
+		if (handle->log_rh) {
+			if (cmd->is_interactive) {
+				/*
+				 * Keep log report if we're interactive so
+				 * we can do further queries on this report.
+				 */
+				cmd->log_rh = handle->log_rh;
+			} else
+				dm_report_free(handle->log_rh);
+		}
 		/*
 		 * TODO: think about better alternatives:
 		 * handle mempool, dm_alloc for handle memory...