Service argument enhancements

doc/manpages/dinit-service.5.m4

@@ -198,7 +198,7 @@ Specifies a file containing value assignments for environment variables, in the
 format recognised by the \fBdinit\fR command's \fB\-\-env\-file\fR option (see \fBdinit\fR(8)).
 The file is read when the service is loaded, therefore values from it can be used in variable
 substitutions (see \fBVARIABLE SUBSTITUTION\fR).
-Variable substitution is not performed on the \fBenv\-file\fR property value itself.
+Minimal variable substitution is performed on the \fBenv\-file\fR property value itself.
 If the path is not absolute, it is resolved relative to the directory containing the service
 description.
 .TP
@@ -784,6 +784,8 @@ The following commands are available:
 \fB@include\fR \fIpath\fR
 Include the contents of another file, specified via its full path.
 If the specified file does not exist, an error is produced.
+The \fIpath\fR is subject to minimal variable substitution
+(see \fBVARIABLE SUBSTITUTION\fR).
 .TP
 \fB@include\-opt\fR \fIpath\fR
 As for \fB@include\fR, but produces no error if the named file does not exist.

src/igr-tests/igr-runner.cc

@@ -995,5 +995,6 @@ void svc_arg_test()
             "test-hello\n" +
             "hello\n" +
             "foo\n" +
-            "foo\n");
+            "foo\n" +
+            "bar\n");
 }

src/igr-tests/svc-arg/checkarg.sh

@@ -1,3 +1,7 @@
 #!/bin/sh
 
 echo "$1" >> "$OUTPUT"
+
+if [ -n "$FOOVAR" ]; then
+    echo "$FOOVAR" >> "$OUTPUT"
+fi

src/igr-tests/svc-arg/sd/checkarg

@@ -2,3 +2,6 @@ type = process
 waits-for = checkarg2@$1
 command = ../checkarg.sh $1
 restart = false
+# this normally only supports absolute paths,
+# but here we control it so just for the test...
+@include-opt sd/inc-$1

src/igr-tests/svc-arg/sd/env-foo

@@ -0,0 +1 @@
+FOOVAR=bar

src/igr-tests/svc-arg/sd/inc-foo

@@ -0,0 +1 @@
+env-file = env-foo

src/includes/load-service.h

@@ -883,6 +883,9 @@ inline void parse_rlimit(const std::string &line, file_pos_ref input_pos,
     }
 }
 
+inline string read_include_path(string const &svcname, string const &meta_cmd, file_pos_ref input_pos,
+        string_iterator &i, string_iterator end, const char *argval);
+
 // Process an opened service file, line by line.
 //    name - the service name
 //    service_input - the service file input stream (stack)
@@ -899,7 +902,7 @@ inline void parse_rlimit(const std::string &line, file_pos_ref input_pos,
 //
 // May throw service load exceptions or I/O exceptions if enabled on stream.
 template <typename T>
-void process_service_file(string name, file_input_stack &service_input, T process_line_func)
+void process_service_file(string name, file_input_stack &service_input, T process_line_func, const char *argval = nullptr)
 {
     string line;
 
@@ -957,12 +960,8 @@ void process_service_file(string name, file_input_stack &service_input, T proces
                 bool is_include_opt = (meta_cmd == "include-opt");
                 if (is_include_opt || meta_cmd == "include") {
                     // @include-opt or @include
-                    std::list<std::pair<unsigned,unsigned>> part_positions;
                     file_pos_ref input_pos { service_input.current_file_name(), line_num };
-                    std::string include_name = read_setting_value(input_pos, i, end, &part_positions);
-                    if (part_positions.size() != 1) {
-                        throw service_description_exc(name, "'@" + meta_cmd + "' requires a single argument", input_pos);
-                    }
+                    std::string include_name = read_include_path(name, meta_cmd, input_pos, i, end, argval);
 
                     std::ifstream file(include_name);
                     file.exceptions(std::ios::badbit);
@@ -1093,9 +1092,9 @@ static void value_var_subst(const char *setting_name, std::string &line,
                 if (name.empty()) {
                     throw service_description_exc(setting_name, "invalid/missing variable name after '$'");
                 }
-                else if (is_arg && (name != "1" || !argval)) {
-                    // only one arg is supported and it must be present
-                    throw service_description_exc(setting_name, "missing value in argument substitution");
+                else if (is_arg && name != "1") {
+                    // only one arg is supported
+                    throw service_description_exc(setting_name, "only one service argument may be present");
                 }
                 char altmode = '\0';
                 bool colon = false;
@@ -1133,11 +1132,17 @@ static void value_var_subst(const char *setting_name, std::string &line,
                     if (!resolved || (colon && !*resolved)) {
                         resolved_vw = {line.c_str() + (altbeg - line.begin()), (size_t)(altend - altbeg)};
                     }
-                } else if (altmode == '+') {
+                }
+                else if (altmode == '+') {
                     if (resolved && (!colon || *resolved)) {
                         resolved_vw = {line.c_str() + (altbeg - line.begin()), (size_t)(altend - altbeg)};
                     }
                 }
+                else if (is_arg && !argval) {
+                    // $1 and ${1} is special in that it must be set or it is an error
+                    // however, we want the more complex syntaxes for conditional substitution
+                    throw service_description_exc(setting_name, "missing value in argument substitution");
+                }
 
                 xpos = j - line.begin();
                 int name_len = xpos - dindx;
@@ -1233,8 +1238,8 @@ static void value_var_subst(const char *setting_name, std::string &line,
     line = std::move(r_line);
 }
 
-// Reads a dependency name while performing minimal argument expansion in it.
-inline string read_dependency_value(const char *setting_name, file_pos_ref input_pos, string_iterator &i,
+// Reads a value while performing minimal argument expansion in it.
+inline string read_value_with_arg(const char *setting_name, file_pos_ref input_pos, string_iterator &i,
         string_iterator end, const char *argval)
 {
     string rval;
@@ -1246,6 +1251,24 @@ inline string read_dependency_value(const char *setting_name, file_pos_ref input
     return rval;
 }
 
+// Reads an include path while performing minimal argument expansion in it.
+inline string read_include_path(string const &svcname, string const &meta_cmd, file_pos_ref input_pos,
+        string_iterator &i, string_iterator end, const char *argval)
+{
+    string rval;
+    std::list<std::pair<unsigned,unsigned>> parts;
+
+    read_setting_value(rval, setting_op_t::ASSIGN, input_pos, i, end, &parts);
+    if (parts.size() != 1) {
+        throw service_description_exc(svcname, "'@" + meta_cmd + "' requires a single argument", input_pos);
+    }
+
+    std::list<std::pair<unsigned,unsigned>> offsets;
+    offsets.emplace_back(0, rval.size());
+    value_var_subst(meta_cmd.c_str(), rval, offsets, resolve_env_var, nullptr, argval);
+    return rval;
+}
+
 // A wrapper type for service parameters. It is parameterised by dependency type.
 template <class dep_type>
 class service_settings_wrapper
@@ -1514,7 +1537,7 @@ void process_service_line(settings_wrapper &settings, const char *name, const ch
             settings.working_dir = read_setting_value(input_pos, i, end, nullptr);
             break;
         case setting_id_t::ENV_FILE:
-            settings.env_file = read_setting_value(input_pos, i, end, nullptr);
+            settings.env_file = read_value_with_arg(setting.c_str(), input_pos, i, end, arg);
             break;
         #if SUPPORT_CGROUPS
         case setting_id_t::RUN_IN_CGROUP:
@@ -1552,21 +1575,21 @@ void process_service_line(settings_wrapper &settings, const char *name, const ch
             break;
         case setting_id_t::DEPENDS_ON:
         {
-            string dependency_name = read_dependency_value(setting.c_str(), input_pos, i, end, arg);
+            string dependency_name = read_value_with_arg(setting.c_str(), input_pos, i, end, arg);
             settings.depends.emplace_back(load_service(dependency_name.c_str()),
                     dependency_type::REGULAR);
             break;
         }
         case setting_id_t::DEPENDS_MS:
         {
-            string dependency_name = read_dependency_value(setting.c_str(), input_pos, i, end, arg);
+            string dependency_name = read_value_with_arg(setting.c_str(), input_pos, i, end, arg);
             settings.depends.emplace_back(load_service(dependency_name.c_str()),
                     dependency_type::MILESTONE);
             break;
         }
         case setting_id_t::WAITS_FOR:
         {
-            string dependency_name = read_dependency_value(setting.c_str(), input_pos, i, end, arg);
+            string dependency_name = read_value_with_arg(setting.c_str(), input_pos, i, end, arg);
             settings.depends.emplace_back(load_service(dependency_name.c_str()),
                     dependency_type::WAITS_FOR);
             break;
@@ -1591,13 +1614,13 @@ void process_service_line(settings_wrapper &settings, const char *name, const ch
         }
         case setting_id_t::AFTER:
         {
-            string after_name = read_dependency_value(setting.c_str(), input_pos, i, end, arg);
+            string after_name = read_value_with_arg(setting.c_str(), input_pos, i, end, arg);
             settings.after_svcs.emplace_back(std::move(after_name));
             break;
         }
         case setting_id_t::BEFORE:
         {
-            string before_name = read_dependency_value(setting.c_str(), input_pos, i, end, arg);
+            string before_name = read_value_with_arg(setting.c_str(), input_pos, i, end, arg);
             settings.before_svcs.emplace_back(std::move(before_name));
             break;
         }

src/load-service.cc

@@ -523,7 +523,7 @@ service_record * dirload_service_set::load_reload_service(const char *fullname,
 
             process_service_line(settings, name.c_str(), argval, line, fpr, setting,
                     op, i, end, load_service_n, process_dep_dir_n);
-        });
+        }, argval);
 
         auto report_err = [&](const char *msg){
             throw service_load_exc(name, msg);