[gnome-builder/wip/gtk4-port] plugins/podman: add support for run contexts

[Christian Hergert <chergert src gnome org>]

commit 4d26651231b5d47e197f1e5f37a51e0efdb772fa
Author: Christian Hergert <chergert redhat com>
Date:   Wed Jun 22 15:46:22 2022 -0700

    plugins/podman: add support for run contexts
    
    This cleans up how we do launching for podman using run contexts. We still
    have some launcher usage for pipelines, but we probably want to make those
    use run contexts as well (eventually).

 src/plugins/podman/gbp-podman-runtime.c | 91 +++++++++++++++++++++++++++++++++
 1 file changed, 91 insertions(+)
---
diff --git a/src/plugins/podman/gbp-podman-runtime.c b/src/plugins/podman/gbp-podman-runtime.c
index c61b995fe..e3deddb66 100644
--- a/src/plugins/podman/gbp-podman-runtime.c
+++ b/src/plugins/podman/gbp-podman-runtime.c
@@ -90,6 +90,96 @@ gbp_podman_runtime_create_launcher (IdeRuntime  *runtime,
   return launcher;
 }
 
+static gboolean
+gbp_podman_runtime_run_handler_cb (IdeRunContext       *run_context,
+                                   const char * const  *argv,
+                                   const char * const  *env,
+                                   const char          *cwd,
+                                   IdeUnixFDMap        *unix_fd_map,
+                                   gpointer             user_data,
+                                   GError             **error)
+{
+  GbpPodmanRuntime *self = user_data;
+  int max_dest_fd;
+
+  IDE_ENTRY;
+
+  g_assert (GBP_IS_PODMAN_RUNTIME (self));
+  g_assert (IDE_IS_RUN_CONTEXT (run_context));
+  g_assert (argv != NULL);
+  g_assert (env != NULL);
+  g_assert (IDE_IS_UNIX_FD_MAP (unix_fd_map));
+
+  /* Make sure we can pass the FDs down */
+  if (!ide_run_context_merge_unix_fd_map (run_context, unix_fd_map, error))
+    IDE_RETURN (FALSE);
+
+  /* Setup basic podman-exec command */
+  ide_run_context_append_args (run_context, IDE_STRV_INIT ("podman", "exec"));
+  ide_run_context_append_argv (run_context, "--privileged");
+  ide_run_context_append_argv (run_context, "--interactive");
+  ide_run_context_append_formatted (run_context, "--user=%s", g_get_user_name ());
+
+  /* Make sure that we request TTY ioctls if necessary */
+  if (ide_unix_fd_map_stdin_isatty (unix_fd_map) ||
+      ide_unix_fd_map_stdout_isatty (unix_fd_map) ||
+      ide_unix_fd_map_stderr_isatty (unix_fd_map))
+    ide_run_context_append_argv (run_context, "--tty");
+
+  /* Specify working directory inside the container */
+  if (cwd != NULL)
+    {
+      g_autofree char *cwd_absolute = g_canonicalize_filename (cwd, NULL);
+      ide_run_context_append_formatted (run_context, "--workdir=%s", cwd_absolute);
+    }
+
+  /* From podman-exec(1):
+   *
+   * Pass down to the process N additional file descriptors (in addition to
+   * 0, 1, 2).  The total FDs will be 3+N.
+   */
+  if ((max_dest_fd = ide_unix_fd_map_get_max_dest_fd (unix_fd_map)) > 2)
+    ide_run_context_append_formatted (run_context, "--preserve-fds=%d", max_dest_fd-2);
+
+  /* Append --env=FOO=BAR environment variables */
+  for (guint i = 0; env[i]; i++)
+    ide_run_context_append_formatted (run_context, "--env=%s", env[i]);
+
+  /* Ensure we have access to the desired PATH from the host */
+  if (g_environ_getenv ((char **)env, "PATH") == NULL)
+    ide_run_context_append_formatted (run_context, "--env=PATH=%s", ide_get_user_default_path ());
+
+  /* Now specify our runtime identifier. Note that self->id is
+   * like :id but w/o podman: prefix */
+  ide_run_context_append_argv (run_context, self->id);
+
+  /* Finally, propagate the upper layer's command arguments */
+  ide_run_context_append_args (run_context, argv);
+
+  IDE_RETURN (TRUE);
+}
+
+static void
+gbp_podman_runtime_prepare_run_context (IdeRuntime    *runtime,
+                                        IdeRunContext *run_context)
+{
+  IDE_ENTRY;
+
+  g_assert (GBP_IS_PODMAN_RUNTIME (runtime));
+  g_assert (IDE_IS_RUN_CONTEXT (run_context));
+
+  /* Our commands will need to be run from the host */
+  ide_run_context_push_host (run_context);
+
+  /* And now push our handler to translate to "podman exec" */
+  ide_run_context_push (run_context,
+                        gbp_podman_runtime_run_handler_cb,
+                        g_object_ref (runtime),
+                        g_object_unref);
+
+  IDE_EXIT;
+}
+
 char *
 _gbp_podman_runtime_parse_toml_line (const char *line)
 {
@@ -462,6 +552,7 @@ gbp_podman_runtime_class_init (GbpPodmanRuntimeClass *klass)
 
   runtime_class->create_launcher = gbp_podman_runtime_create_launcher;
   runtime_class->translate_file = gbp_podman_runtime_translate_file;
+  runtime_class->prepare_run_context = gbp_podman_runtime_prepare_run_context;
 }
 
 static void