cgtop: add -M/--machine

man/systemd-cgtop.xml

@@ -246,6 +246,15 @@
         3.</para></listitem>
       </varlistentry>
 
+      <varlistentry>
+        <term><option>-M <replaceable>MACHINE</replaceable></option></term>
+        <term><option>--machine=<replaceable>MACHINE</replaceable></option></term>
+
+        <listitem><para>Limit control groups shown to the part
+        corresponding to the container
+        <replaceable>MACHINE</replaceable>.</para></listitem>
+      </varlistentry>
+
       <xi:include href="standard-options.xml" xpointer="help" />
       <xi:include href="standard-options.xml" xpointer="version" />
     </variablelist>

shell-completion/bash/systemd-cgtop

@@ -24,17 +24,32 @@ __contains_word() {
         done
 }
 
+__get_machines() {
+        local a b
+        machinectl list --no-legend --no-pager | { while read a b; do echo " $a"; done; };
+}
+
 _systemd_cgtop() {
         local cur=${COMP_WORDS[COMP_CWORD]} prev=${COMP_WORDS[COMP_CWORD-1]}
         local comps
 
         local -A OPTS=(
                [STANDALONE]='-h --help --version -p -t -c -m -i -b --batch -n --iterations -d --delay'
-               [ARG]='--cpu --depth'
+               [ARG]='--cpu --depth -M --machine'
                )
 
         _init_completion || return
 
+        if __contains_word "$prev" ${OPTS[ARG]}; then
+                case $prev in
+                        --machine|-M)
+                                comps=$( __get_machines )
+                        ;;
+                esac
+                COMPREPLY=( $(compgen -W '$comps' -- "$cur") )
+                return 0
+        fi
+
         COMPREPLY=( $(compgen -W '${OPTS[*]}' -- "$cur") )
 }
 

src/cgtop/cgtop.c

@@ -36,6 +36,10 @@
 #include "cgroup-util.h"
 #include "build.h"
 #include "fileio.h"
+#include "sd-bus.h"
+#include "bus-util.h"
+#include "bus-error.h"
+#include "unit-name.h"
 
 typedef struct Group {
         char *path;
@@ -65,6 +69,7 @@ static unsigned arg_iterations = (unsigned) -1;
 static bool arg_batch = false;
 static bool arg_raw = false;
 static usec_t arg_delay = 1*USEC_PER_SEC;
+static char* arg_machine = NULL;
 
 enum {
         COUNT_PIDS,
@@ -645,6 +650,7 @@ static void help(void) {
                "  -n --iterations=N   Run for N iterations before exiting\n"
                "  -b --batch          Run in batch mode, accepting no input\n"
                "     --depth=DEPTH    Maximum traversal depth (default: %u)\n"
+               "  -M --machine=       Show container\n"
                , program_invocation_short_name, arg_depth);
 }
 
@@ -669,6 +675,7 @@ static int parse_argv(int argc, char *argv[]) {
                 { "cpu",          optional_argument, NULL, ARG_CPU_TYPE  },
                 { "order",        required_argument, NULL, ARG_ORDER     },
                 { "recursive",    required_argument, NULL, ARG_RECURSIVE },
+                { "machine",      required_argument, NULL, 'M'           },
                 {}
         };
 
@@ -678,7 +685,7 @@ static int parse_argv(int argc, char *argv[]) {
         assert(argc >= 1);
         assert(argv);
 
-        while ((c = getopt_long(argc, argv, "hptcmin:brd:kP", options, NULL)) >= 0)
+        while ((c = getopt_long(argc, argv, "hptcmin:brd:kPM:", options, NULL)) >= 0)
 
                 switch (c) {
 
@@ -797,6 +804,10 @@ static int parse_argv(int argc, char *argv[]) {
                         recursive_unset = r == 0;
                         break;
 
+                case 'M':
+                        arg_machine = optarg;
+                        break;
+
                 case '?':
                         return -EINVAL;
 
@@ -826,6 +837,48 @@ static const char* counting_what(void) {
                 return "userspace processes (excl. kernel)";
 }
 
+static int get_cgroup_root(char **ret) {
+        _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
+        _cleanup_bus_flush_close_unref_ sd_bus *bus = NULL;
+        _cleanup_free_ char *unit = NULL, *path = NULL;
+        const char *m;
+        int r;
+
+        if (!arg_machine) {
+                r = cg_get_root_path(ret);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to get root control group path: %m");
+
+                return 0;
+        }
+
+        m = strjoina("/run/systemd/machines/", arg_machine);
+        r = parse_env_file(m, NEWLINE, "SCOPE", &unit, NULL);
+        if (r < 0)
+                return log_error_errno(r, "Failed to load machine data: %m");
+
+        path = unit_dbus_path_from_name(unit);
+        if (!path)
+                return log_oom();
+
+        r = bus_open_transport(BUS_TRANSPORT_LOCAL, NULL, false, &bus);
+        if (r < 0)
+                return log_error_errno(r, "Failed to create bus connection: %m");
+
+        r = sd_bus_get_property_string(
+                        bus,
+                        "org.freedesktop.systemd1",
+                        path,
+                        unit_dbus_interface_from_name(unit),
+                        "ControlGroup",
+                        &error,
+                        ret);
+        if (r < 0)
+                return log_error_errno(r, "Failed to query unit control group path: %s", bus_error_message(&error, r));
+
+        return 0;
+}
+
 int main(int argc, char *argv[]) {
         int r;
         Hashmap *a = NULL, *b = NULL;
@@ -850,7 +903,7 @@ int main(int argc, char *argv[]) {
         if (r <= 0)
                 goto finish;
 
-        r = cg_get_root_path(&root);
+        r = get_cgroup_root(&root);
         if (r < 0) {
                 log_error_errno(r, "Failed to get root control group path: %m");
                 goto finish;