common/options: add configs for temporary files made by daemons

Signed-off-by: Patrick Donnelly <pdonnell@redhat.com>

src/common/config.cc

@@ -493,6 +493,11 @@ void md_config_t::parse_env(unsigned entity_type,
     }
   }
 
+  if (auto s = getenv("TMPDIR"); s) {
+    string err;
+    _set_val(values, tracker, s, *find_option("tmp_dir"), CONF_ENV, &err);
+  }
+
   // Apply pod memory limits:
   //
   // There are two types of resource requests: `limits` and `requests`.

src/common/options/global.yaml.in

@@ -250,6 +250,29 @@ options:
   flags:
   - startup
   with_legacy: true
+- name: tmp_dir
+  type: str
+  level: advanced
+  desc: path for the 'tmp' directory
+  default: /tmp
+  services:
+  - common
+  see_also:
+  - admin_socket
+  flags:
+  - runtime
+- name: tmp_file_template
+  type: str
+  level: advanced
+  desc: Template for temporary files created by daemons for ceph tell commands
+  long_desc: The template file name prefix for temporary files. For example, temporary files may be created by `ceph tell` commands using the --daemon-output-file switch.
+  daemon_default: $tmp_dir/$cluster-$name.XXXXXX
+  services:
+  - osd
+  - mds
+  - mon
+  flags:
+  - runtime
 - name: admin_socket
   type: str
   level: advanced