PR #1798: ch-run: add --quiet

bin/ch-completion.bash

@@ -258,7 +258,6 @@ _ch_image_complete () {
         __ltrim_colon_completions "$cur"
         ;;
     undelete)
-        # FIXME: Update with “ch-image undelete --list” once #1551 drops
         COMPREPLY=( $(compgen -W "$(_ch_undelete_list "$strg_dir")" -- "$cur") )
         ;;
     '')
@@ -281,7 +280,7 @@ _ch_image_complete () {
 
 _run_opts="-b --bind -c --cd --env-no-expand --feature -g --gid
            --home -j --join --join-pid --join-ct --join-tag -m
-           --mount --no-passwd -s --storage --seccomp -t
+           --mount --no-passwd -q --quiet -s --storage --seccomp -t
            --private-tmp --set-env -u --uid --unsafe --unset-env
            -v --verbose -w --write -? --help --usage -V --version"
 

bin/ch-run.c

@@ -60,9 +60,11 @@ const struct argp_option options[] = {
    { "join-pid",       -5, "PID",  0, "join a namespace using a PID" },
    { "join-ct",        -3, "N",    0, "number of join peers (implies --join)" },
    { "join-tag",       -4, "TAG",  0, "label for peer group (implies --join)" },
+   { "test",          -17, "TEST", 0, "do test TEST" },
    { "mount",         'm', "DIR",  0, "SquashFS mount point"},
    { "no-passwd",      -9, 0,      0, "don't bind-mount /etc/{passwd,group}"},
    { "private-tmp",   't', 0,      0, "use container-private /tmp" },
+   { "quiet",         'q', 0,      0, "print less output (can be repeated)"},
 #ifdef HAVE_SECCOMP
    { "seccomp",       -14, 0,      0,
                            "fake success for some syscalls with seccomp(2)"},
@@ -476,13 +478,21 @@ static error_t parse_opt(int key, char *arg, struct argp_state *state)
       args->seccomp_p = true;
       break;
 #endif
+   case -15: // --set-env0
+      parse_set_env(args, arg, '\0');
+      break;
    case -16: // --warnings
       for (int i = 1; i <= parse_int(arg, false, "--warnings"); i++)
          WARNING("this is warning %d!", i);
       exit(0);
       break;
-   case -15: // --set-env0
-      parse_set_env(args, arg, '\0');
+   case -17: // --test
+      if (!strcmp(arg, "log"))
+         test_logging(false);
+      else if (!strcmp(arg, "log-fail"))
+         test_logging(true);
+      else
+         FATAL("invalid --test argument: %s; see source code", arg);
       break;
    case 'b': {  // --bind
          char *src, *dst;
@@ -525,6 +535,11 @@ static error_t parse_opt(int key, char *arg, struct argp_state *state)
       if (!path_exists(arg, NULL, false))
          WARNING("storage directory not found: %s", arg);
       break;
+   case 'q':  // --quiet
+      Te(verbose <= 0, "--quiet incompatible with --verbose");
+      verbose--;
+      Te(verbose >= -3, "--quiet can be specified at most thrice");
+      break;
    case 't':  // --private-tmp
       args->c.private_tmp = true;
       break;
@@ -538,6 +553,7 @@ static error_t parse_opt(int key, char *arg, struct argp_state *state)
       exit(EXIT_SUCCESS);
       break;
    case 'v':  // --verbose
+      Te(verbose >= 0, "--verbose incompatible with --quiet");
       verbose++;
       Te(verbose <= 3, "--verbose can be specified at most thrice");
       break;

bin/ch_core.c

@@ -536,6 +536,10 @@ void run_user_command(char *argv[], const char *initial_dir)
    VERBOSE("executing: %s", argv_to_string(argv));
 
    Zf (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0), "can't set no_new_privs");
+   if (verbose < LL_INFO)
+      T_ (freopen("/dev/null", "w", stdout));
+   if (verbose < LL_STDERR)
+      T_ (freopen("/dev/null", "w", stderr));
    execvp(argv[0], argv);  // only returns if error
    Tf (0, "can't execve(2): %s", argv[0]);
 }

bin/ch_misc.c

@@ -442,6 +442,17 @@ void log_ids(const char *func, int line)
    }
 }
 
+void test_logging(bool fail) {
+   TRACE("trace");
+   DEBUG("debug");
+   VERBOSE("verbose");
+   INFO("info");
+   WARNING("warning");
+   if (fail)
+      FATAL("the program failed inexplicably (\"log-fail\" specified)");
+   exit(0);
+}
+
 /* Create the directory at path, despite its parent not allowing write access,
    by overmounting a new, writeable directory atop it. We preserve the old
    contents by bind-mounting the old directory as a subdirectory, then setting

bin/ch_misc.h

@@ -95,9 +95,10 @@ struct env_delta {
    } arg;
 };
 
-enum log_level { LL_FATAL =   -2,  // minimum number of -v to print the msg
+enum log_level { LL_FATAL =   -3,
+                 LL_STDERR =  -2,
                  LL_WARNING = -1,
-                 LL_INFO =     0,
+                 LL_INFO =     0,  // minimum number of -v to print the msg
                  LL_VERBOSE =  1,
                  LL_DEBUG =    2,
                  LL_TRACE =    3 };
@@ -128,6 +129,7 @@ struct env_var env_var_parse(const char *line, const char *path, size_t lineno);
 void list_append(void **ar, void *new, size_t size);
 void *list_new(size_t size, size_t ct);
 void log_ids(const char *func, int line);
+void test_logging(bool fail);
 void mkdirs(const char *base, const char *path, char **denylist,
             const char *scratch);
 void msg(enum log_level level, const char *file, int line, int errno_,

doc/ch-run.rst

@@ -97,6 +97,10 @@ mounting SquashFS images with FUSE.
     bind-mounted into it. If this is specified, no such temporary files are
     created and the image’s files are exposed.
 
+  :code:`-q`, :code:`--quiet`
+    Be quieter; can be repeated. Incompatible with :code:`-v`. See the
+    :ref:`faq_verbosity` for details.
+
   :code:`-s`, :code:`--storage DIR`
     Set the storage directory. Equivalent to the same option for
     :code:`ch-image(1)`.
@@ -131,7 +135,8 @@ mounting SquashFS images with FUSE.
     Unset environment variables whose names match :code:`GLOB`.
 
   :code:`-v`, :code:`--verbose`
-    Be more verbose (can be repeated).
+    Print extra chatter; can be repeated. See the :ref:`FAQ entry on verbosity
+    <faq_verbosity>` for details.
 
   :code:`-w`, :code:`--write`
     Mount image read-write. By default, the image is mounted read-only. *This

doc/faq.rst

@@ -1289,7 +1289,7 @@ indicates printed, ❌ suppressed).
      - ✅
      - [1]
      - [1]
-     - [1]
+     - [1] [2]
      - ❌
      - ❌
    * - warning
@@ -1324,6 +1324,10 @@ Notes:
    :code:`RUN`) and sometimes it’s captured for internal use (e.g., many
    :code:`git(1)` invocations).
 
+
+2. In the case of :code:`ch-run`, the user command is considered a subprocess,
+   e.g. :code:`ch-run -q example -- echo foo` will produce no output.
+
 .. _faq_xattrs:
 
 How do I handle extended attributes in Charliecloud?
@@ -1357,6 +1361,7 @@ conversion. Important caveats include:
    in the :code:`user` namespace prior to Linux kernel `upstream 6.6
    <https://kernelnewbies.org/Linux_6.6#TMPFSe>`_ (Oct 2023).
 
+
 ..  LocalWords:  CAs SY Gutmann AUTH rHsFFqwwqh MrieaQ Za loc mpihello mvo du
 ..  LocalWords:  VirtualSize linuxcontainers jour uk lxd rwxr xr qq qqq drwxr
 ..  LocalWords:  drwx

test/run/ch-run_misc.bats

@@ -1118,6 +1118,55 @@ EOF
 
 }
 
+@test 'ch-run --quiet' {
+    # test --logging-test
+    run ch-run --test=log
+    echo "$output"
+    [[ $status -eq 0 ]]
+    [[ $output = *'info'* ]]
+    [[ $output = *'warning: warning'* ]]
+
+    # quiet level 1
+    run ch-run -q --test=log
+    echo "$output"
+    [[ $status -eq 0 ]]
+    [[ $output != *'info'* ]]
+    [[ $output = *'warning: warning'* ]]
+
+    # quiet level 2
+    run ch-run -qq --test=log
+    echo "$output"
+    [[ $status -eq 0 ]]
+    [[ $output != *'info'* ]]
+    [[ $output != *'warning: warning'* ]]
+
+    # subprocess failure at quiet level 2
+    run ch-run -qq "$ch_timg" -- doesnotexist
+    echo "$output"
+    [[ $status -eq 1 ]]
+    [[ $output = *"error: can't execve(2): doesnotexist: No such file or directory"* ]]
+
+    # quiet level 3
+    run ch-run -qqq --test=log
+    echo "$output"
+    [[ $status -eq 0 ]]
+    [[ $output != *'info'* ]]
+    [[ $output != *"warning: warning"* ]]
+
+    # subprocess failure at quiet level 3
+    run ch-run -qqq "$ch_timg" -- doesnotexist
+    echo "$output"
+    [[ $status -eq 1 ]]
+    [[ $output != *"error: can't execve(2): doesnotexist: No such file or directory"* ]]
+
+    # failure at quiet level 3
+    run ch-run -qqq --test=log-fail
+    echo "$output"
+    [[ $status -eq 1 ]]
+    [[ $output != *'info'* ]]
+    [[ $output != *'warning: warning'* ]]
+    [[ $output = *'error: the program failed inexplicably'* ]]
+}
 
 @test 'ch-run --write-fake errors' {
     demand-overlayfs