rpmmd: require the path to dnf-json to be passed in

RPMMD had hardcoded path to dnf-json helper. This required all executables
using RPMMD to be run in the directory where dnf-json was located. This commit
makes RPMMD take the path to dnf-json as an argument. This allows its
consumers to specify whichever path they want.

Not a functional change

cmd/osbuild-composer/main.go

@@ -87,7 +87,9 @@ func main() {
 		log.Fatal("CACHE_DIRECTORY is not set. Is the service file missing CacheDirectory=?")
 	}
 
-	rpm := rpmmd.NewRPMMD(path.Join(cacheDirectory, "rpmmd"))
+	// osbuild-composer must be run in /usr/libexec/osbuild-composer directory,
+	// therefore use ./dnf-json as the path to dnf-json.
+	rpm := rpmmd.NewRPMMD(path.Join(cacheDirectory, "rpmmd"), "./dnf-json")
 
 	distros, err := distro.NewRegistry(fedora31.New(), fedora32.New(), rhel8.New())
 	if err != nil {

cmd/osbuild-dnf-json-tests/main_test.go

@@ -34,7 +34,8 @@ func TestFetchChecksum(t *testing.T) {
 		BaseURL:   fmt.Sprintf("file://%s", dir),
 		IgnoreSSL: true,
 	}
-	rpmMetadata := rpmmd.NewRPMMD(path.Join(dir, "rpmmd"))
+
+	rpmMetadata := rpmmd.NewRPMMD(path.Join(dir, "rpmmd"), "./dnf-json")
 	_, c, err := rpmMetadata.FetchMetadata([]rpmmd.RepoConfig{repoCfg}, "platform:f31", "x86_64")
 	assert.Nilf(t, err, "Failed to fetch checksum: %v", err)
 	assert.NotEqual(t, "", c["repo"], "The checksum is empty")
@@ -58,7 +59,8 @@ func TestCrossArchDepsolve(t *testing.T) {
 			dir, err := ioutil.TempDir("/tmp", "rpmmd-test-")
 			require.Nilf(t, err, "Failed to create tmp dir for depsolve test: %v", err)
 			defer os.RemoveAll(dir)
-			rpm := rpmmd.NewRPMMD(dir)
+
+			rpm := rpmmd.NewRPMMD(dir, "./dnf-json")
 
 			repos, err := rpmmd.LoadRepositories([]string{repoDir}, distroStruct.Name())
 			require.NoErrorf(t, err, "Failed to LoadRepositories %v", distroStruct.Name())

cmd/osbuild-pipeline/main.go

@@ -132,7 +132,7 @@ func main() {
 		panic("os.UserHomeDir(): " + err.Error())
 	}
 
-	rpmmd := rpmmd.NewRPMMD(path.Join(home, ".cache/osbuild-composer/rpmmd"))
+	rpmmd := rpmmd.NewRPMMD(path.Join(home, ".cache/osbuild-composer/rpmmd"), "./dnf-json")
 	packageSpecs, checksums, err := rpmmd.Depsolve(packages, excludePkgs, repos, d.ModulePlatformID(), arch.Name())
 	if err != nil {
 		panic("Could not depsolve: " + err.Error())

cmd/osbuild-store-dump/main.go

@@ -137,7 +137,7 @@ func main() {
 	if err != nil {
 		panic("os.UserHomeDir(): " + err.Error())
 	}
-	rpmmd := rpmmd.NewRPMMD(path.Join(homeDir, ".cache/osbuild-composer/rpmmd"))
+	rpmmd := rpmmd.NewRPMMD(path.Join(homeDir, ".cache/osbuild-composer/rpmmd"), "./dnf-json")
 
 	s := store.New(&cwd, a, nil)
 	if s == nil {