module: Warn if module config file is inaccessible

libdnf/conf/ConfigParser.cpp

@@ -271,6 +271,8 @@ void ConfigParser::read(const std::string & filePath)
     try {
         IniParser parser(filePath);
         ::libdnf::read(*this, parser);
+    } catch (const IniParser::FileDoesNotExist & e) {
+        throw FileDoesNotExist(e.what());
     } catch (const IniParser::CantOpenFile & e) {
         throw CantOpenFile(e.what());
     } catch (const IniParser::Exception & e) {

libdnf/conf/ConfigParser.hpp

@@ -55,6 +55,9 @@ struct ConfigParser {
     struct CantOpenFile : public Exception {
         CantOpenFile(const std::string & what) : Exception(what) {}
     };
+    struct FileDoesNotExist : public CantOpenFile {
+        FileDoesNotExist(const std::string & what) : CantOpenFile(what) {}
+    };
     struct ParsingError : public Exception {
         ParsingError(const std::string & what) : Exception(what) {}
     };

libdnf/module/ModulePackageContainer.cpp

@@ -1370,10 +1370,10 @@ static inline void
 parseConfig(ConfigParser &parser, const std::string &name, const char *path)
 {
     auto logger(Log::getLogger());
+    const auto fname = name + ".module";
+    g_autofree gchar * cfn = g_build_filename(path, fname.c_str(), NULL);
 
     try {
-        const auto fname = name + ".module";
-        g_autofree gchar * cfn = g_build_filename(path, fname.c_str(), NULL);
         parser.read(cfn);
 
         /* FIXME: init empty config or throw error? */
@@ -1393,10 +1393,15 @@ parseConfig(ConfigParser &parser, const std::string &name, const char *path)
             parser.setValue(name, "state", parser.getValue(name, "enabled"));
             parser.removeOption(name, "enabled");
         }
-    } catch (const ConfigParser::CantOpenFile &) {
+    } catch (const ConfigParser::FileDoesNotExist &) {
         /* No module config file present. Fill values in */
         initConfig(parser, name);
         return;
+    } catch (const ConfigParser::CantOpenFile &) {
+        /* File exists but is not readable. */
+        logger->warning(tfm::format("Cannot read \"%s\". Modular filtering may be affected.", cfn));
+        initConfig(parser, name);
+        return;
     }
 }
 

libdnf/utils/iniparser/iniparser.cpp

@@ -20,13 +20,21 @@
 
 #include "iniparser.hpp"
 
+#include <errno.h>
+#include <sys/stat.h>
+
 constexpr char DELIMITER = '\n';
 
 const char * IniParser::CantOpenFile::what() const noexcept
 {
     return "IniParser: Can't open file";
 }
 
+const char * IniParser::FileDoesNotExist::what() const noexcept
+{
+    return "IniParser: File does not exist";
+}
+
 const char * IniParser::MissingSectionHeader::what() const noexcept
 {
     return "IniParser: Missing section header";
@@ -65,8 +73,13 @@ const char * IniParser::MissingEqual::what() const noexcept
 IniParser::IniParser(const std::string & filePath)
 : is(new std::ifstream(filePath))
 {
-    if (!(*is))
+    if (!(*is)) {
+        struct stat buffer;
+        if (stat(filePath.c_str(), &buffer) != 0 && errno == ENOENT) {
+            throw FileDoesNotExist();
+        }
         throw CantOpenFile();
+    }
     is->exceptions(std::ifstream::badbit);
     lineNumber = 0;
     lineReady = false;

libdnf/utils/iniparser/iniparser.hpp

@@ -46,6 +46,10 @@ class IniParser {
         CantOpenFile() {}
         const char * what() const noexcept override;
     };
+    struct FileDoesNotExist : public CantOpenFile {
+        FileDoesNotExist() {}
+        const char * what() const noexcept override;
+    };
     struct MissingSectionHeader : public Exception {
         MissingSectionHeader(int lineNumber) : Exception(lineNumber) {}
         const char * what() const noexcept override;