File 0180-Disksup-parsing-for-df-output-on-POSIX-and-SUSv3-sys.patch of Package erlang
From ae49fdda74a72f9fea596dba4f0470163f28d4b5 Mon Sep 17 00:00:00 2001
From: Dmytro Lytovchenko <dmytro.lytovchenko@gmail.com>
Date: Tue, 4 Jul 2017 15:21:26 +0200
Subject: [PATCH] Disksup parsing for 'df' output on POSIX and SUSv3 systems
Tests for disksup:parse_df
---
lib/os_mon/src/disksup.erl | 98 +++++++++++++++++++++++++++++++++++++--
lib/os_mon/test/disksup_SUITE.erl | 38 ++++++++++++++-
2 files changed, 129 insertions(+), 7 deletions(-)
diff --git a/lib/os_mon/src/disksup.erl b/lib/os_mon/src/disksup.erl
index 492e4814d..36730aac7 100644
--- a/lib/os_mon/src/disksup.erl
+++ b/lib/os_mon/src/disksup.erl
@@ -32,7 +32,7 @@
terminate/2, code_change/3]).
%% Other exports
--export([format_status/2]).
+-export([format_status/2, parse_df/2]).
-record(state, {threshold, timeout, os, diskdata = [],port}).
@@ -294,8 +294,8 @@ check_disks_solaris("", _Threshold) ->
check_disks_solaris("\n", _Threshold) ->
[];
check_disks_solaris(Str, Threshold) ->
- case io_lib:fread("~s~d~d~d~d%~s", Str) of
- {ok, [_FS, KB, _Used, _Avail, Cap, MntOn], RestStr} ->
+ case parse_df(Str, posix) of
+ {ok, {KB, Cap, MntOn}, RestStr} ->
if
Cap >= Threshold ->
set_alarm({disk_almost_full, MntOn}, []);
@@ -308,14 +308,102 @@ check_disks_solaris(Str, Threshold) ->
check_disks_solaris(skip_to_eol(Str),Threshold)
end.
+%% @private
+%% @doc Predicate to take a word from the input string until a space or
+%% a percent '%' sign (the Capacity field is followed by a %)
+parse_df_is_not_space($ ) -> false;
+parse_df_is_not_space($%) -> false;
+parse_df_is_not_space(_) -> true.
+
+%% @private
+%% @doc Predicate to take spaces away from string. Stops on a non-space
+parse_df_is_space($ ) -> true;
+parse_df_is_space(_) -> false.
+
+%% @private
+%% @doc Predicate to consume remaining characters until end of line.
+parse_df_is_not_eol($\r) -> false;
+parse_df_is_not_eol($\n) -> false;
+parse_df_is_not_eol(_) -> true.
+
+%% @private
+%% @doc Trims leading non-spaces (the word) from the string then trims spaces.
+parse_df_skip_word(Input) ->
+ Remaining = lists:dropwhile(fun parse_df_is_not_space/1, Input),
+ lists:dropwhile(fun parse_df_is_space/1, Remaining).
+
+%% @private
+%% @doc Takes all non-spaces and then drops following spaces.
+parse_df_take_word(Input) ->
+ {Word, Remaining0} = lists:splitwith(fun parse_df_is_not_space/1, Input),
+ Remaining1 = lists:dropwhile(fun parse_df_is_space/1, Remaining0),
+ {Word, Remaining1}.
+
+%% @private
+%% @doc Takes all non-spaces and then drops the % after it and the spaces.
+parse_df_take_word_percent(Input) ->
+ {Word, Remaining0} = lists:splitwith(fun parse_df_is_not_space/1, Input),
+ %% Drop the leading % or do nothing
+ Remaining1 = case Remaining0 of
+ [$% | R1] -> R1;
+ _ -> Remaining0 % Might be no % or empty list even
+ end,
+ Remaining2 = lists:dropwhile(fun parse_df_is_space/1, Remaining1),
+ {Word, Remaining2}.
+
+%% @private
+%% @doc Given a line of 'df' POSIX/SUSv3 output split it into fields:
+%% a string (mounted device), 4 integers (kilobytes, used, available
+%% and capacity), skip % sign, (optionally for susv3 can also skip IUsed, IFree
+%% and ICap% fields) then take remaining characters as the mount path
+-spec parse_df(string(), posix | susv3) ->
+ {error, parse_df} | {ok, {integer(), integer(), integer()}, string()}.
+parse_df(Input0, Flavor) ->
+ %% Format of Posix/Linux df output looks like Header + Lines
+ %% Filesystem 1024-blocks Used Available Capacity Mounted on
+ %% udev 2467108 0 2467108 0% /dev
+ Input1 = parse_df_skip_word(Input0), % skip device path field
+ {KbStr, Input2} = parse_df_take_word(Input1), % take Kb field
+ Input3 = parse_df_skip_word(Input2), % skip Used field
+ Input4 = parse_df_skip_word(Input3), % skip Avail field
+
+ % take Capacity% field; drop a % sign following the capacity
+ {CapacityStr, Input5} = parse_df_take_word_percent(Input4),
+
+ %% Format of OS X/SUSv3 df looks similar to POSIX but has 3 extra columns
+ %% Filesystem 1024-blocks Used Available Capacity iused ifree %iused Mounted
+ %% /dev/disk1 243949060 2380 86690680 65% 2029724 37555 0% /
+ Input6 = case Flavor of
+ posix -> Input5;
+ susv3 -> % there are 3 extra integers we want to skip
+ Input5a = parse_df_skip_word(Input5), % skip IUsed field
+ Input5b = parse_df_skip_word(Input5a), % skip IFree field
+ %% skip the value of ICap + '%' field
+ {_, Input5c} = parse_df_take_word_percent(Input5b),
+ Input5c
+ end,
+
+ % path is the remaining string till end of line
+ {MountPath, Input7} = lists:splitwith(fun parse_df_is_not_eol/1, Input6),
+ % Trim the newlines
+ Remaining = lists:dropwhile(fun(X) -> not parse_df_is_not_eol(X) end,
+ Input7),
+ try
+ Kb = erlang:list_to_integer(KbStr),
+ Capacity = erlang:list_to_integer(CapacityStr),
+ {ok, {Kb, Capacity, MountPath}, Remaining}
+ catch error:badarg ->
+ {error, parse_df}
+ end.
+
% Parse per SUSv3 specification, notably recent OS X
check_disks_susv3("", _Threshold) ->
[];
check_disks_susv3("\n", _Threshold) ->
[];
check_disks_susv3(Str, Threshold) ->
- case io_lib:fread("~s~d~d~d~d%~d~d~d%~s", Str) of
- {ok, [_FS, KB, _Used, _Avail, Cap, _IUsed, _IFree, _ICap, MntOn], RestStr} ->
+ case parse_df(Str, susv3) of
+ {ok, {KB, Cap, MntOn}, RestStr} ->
if
Cap >= Threshold ->
set_alarm({disk_almost_full, MntOn}, []);
diff --git a/lib/os_mon/test/disksup_SUITE.erl b/lib/os_mon/test/disksup_SUITE.erl
index ad6198501..d7f262616 100644
--- a/lib/os_mon/test/disksup_SUITE.erl
+++ b/lib/os_mon/test/disksup_SUITE.erl
@@ -30,7 +30,7 @@
-export([port/1]).
-export([terminate/1, unavailable/1, restart/1]).
-export([otp_5910/1]).
--export([posix_only/1]).
+-export([posix_only/1, parse_df_output_posix/1, parse_df_output_susv3/1]).
init_per_suite(Config) when is_list(Config) ->
ok = application:start(os_mon),
@@ -59,7 +59,8 @@ suite() ->
all() ->
Bugs = [otp_5910],
- Always = [api, config, alarm, port, posix_only, unavailable] ++ Bugs,
+ Always = [api, config, alarm, port, posix_only, unavailable,
+ parse_df_output_posix, parse_df_output_susv3] ++ Bugs,
case test_server:os_type() of
{unix, _OSname} -> Always;
{win32, _OSname} -> Always;
@@ -413,3 +414,36 @@ get_disk_data([{"none",0,0}=E]) -> [E];
get_disk_data([{_,_,0}|Es]) -> get_disk_data(Es);
get_disk_data([E|Es]) -> [E|get_disk_data(Es)];
get_disk_data([]) -> [].
+
+%% @doc Test various expected inputs to 'df' command output (Linux/POSIX)
+parse_df_output_posix(Config) when is_list(Config) ->
+ PosixHdr = "Filesystem 1K-blocks Used Available Use% Mounted on\n",
+ {error, _} = disksup:parse_df(PosixHdr, posix),
+ {error, _} = disksup:parse_df("", posix),
+ {error, _} = disksup:parse_df("\n\n", posix),
+
+ %% Have a simple example with no funny spaces in mount path
+ Posix1 = "tmpfs 498048 7288 490760 2% /run\n",
+ {ok, {498048, 2, "/run"}, ""} = disksup:parse_df(Posix1, posix),
+
+ %% Have a mount path with some spaces in it
+ Posix2 = "tmpfs 498048 7288 490760 2% /spaces 1 2\n",
+ {ok, {498048, 2, "/spaces 1 2"}, ""} = disksup:parse_df(Posix2, posix).
+
+%% @doc Test various expected inputs to 'df' command output (Darwin/SUSv3)
+parse_df_output_susv3(Config) when is_list(Config) ->
+ DarwinHdr = "Filesystem 1024-blocks Used Available Capacity " ++
+ "iused ifree %iused Mounted on",
+ {error, _} = disksup:parse_df(DarwinHdr, susv3),
+ {error, _} = disksup:parse_df("", susv3),
+ {error, _} = disksup:parse_df("\n\n", susv3),
+
+ %% Have a simple example with no funny spaces in mount path
+ Darwin1 = "/dev/disk1 243949060 157002380 86690680 65% 2029724 " ++
+ "4292937555 0% /\n",
+ {ok, {243949060, 65, "/"}, ""} = disksup:parse_df(Darwin1, susv3),
+
+ %% Have a mount path with some spaces in it
+ Darwin2 = "/dev/disk1 243949060 157002380 86690680 65% 2029724 " ++
+ "4292937555 0% /spaces 1 2\n",
+ {ok, {243949060, 65, "/spaces 1 2"}, ""} = disksup:parse_df(Darwin2, susv3).
--
2.13.3
