test: Add libkpod config tests

- config_test.go for testing libkpod/config.go
- testdata/config.toml as a fixture for config_test.go

Signed-off-by: Steve Milner <smilner@redhat.com>

libkpod/config_test.go

@@ -0,0 +1,54 @@
+package libkpod
+
+import (
+	"io/ioutil"
+	"os"
+	"testing"
+)
+
+// TestConfigToFile ensures Config.ToFile(..) encodes and writes out
+// a Config instance toa a file on disk.
+func TestConfigToFile(t *testing.T) {
+	// Test with a default configuration
+	c := DefaultConfig()
+	tmpfile, err := ioutil.TempFile("", "config")
+	if err != nil {
+		t.Fatalf("Unable to create temporary file: %+v", err)
+	}
+	// Clean up temporary file
+	defer os.Remove(tmpfile.Name())
+
+	// Make the ToFile calls
+	err = c.ToFile(tmpfile.Name())
+	// Make sure no errors occurred while populating the file
+	if err != nil {
+		t.Fatalf("Unable to write to temporary file: %+v", err)
+	}
+
+	// Make sure the file is on disk
+	if _, err := os.Stat(tmpfile.Name()); os.IsNotExist(err) {
+		t.Fatalf("The config file was not written to disk: %+v", err)
+	}
+}
+
+// TestConfigUpdateFromFile ensures Config.UpdateFromFile(..) properly
+// updates an already create Config instancec with new data.
+func TestConfigUpdateFromFile(t *testing.T) {
+	// Test with a default configuration
+	c := DefaultConfig()
+	// Make the ToFile calls
+	err := c.UpdateFromFile("testdata/config.toml")
+	// Make sure no errors occurred while populating from the file
+	if err != nil {
+		t.Fatalf("Unable update config from file: %+v", err)
+	}
+
+	// Check fields that should have changed after UpdateFromFile
+	if c.Storage != "overlay2" {
+		t.Fatalf("Update failed. Storage did not change to overlay2")
+	}
+
+	if c.RuntimeConfig.PidsLimit != 2048 {
+		t.Fatalf("Update failed. RuntimeConfig.PidsLimit did not change to 2048")
+	}
+}

libkpod/testdata/config.toml

@@ -0,0 +1,28 @@
+[crio]
+  root = "/var/lib/containers/storage"
+  runroot = "/var/run/containers/storage"
+  storage_driver = "overlay2"
+  log_dir = "/var/log/crio/pods"
+  file_locking = true
+  [crio.runtime]
+    runtime = "/usr/bin/runc"
+    runtime_untrusted_workload = ""
+    default_workload_trust = "trusted"
+    conmon = "/usr/local/libexec/crio/conmon"
+    conmon_env = ["PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"]
+    selinux = true
+    seccomp_profile = "/etc/crio/seccomp.json"
+    apparmor_profile = "crio-default"
+    cgroup_manager = "cgroupfs"
+    hooks_dir_path = "/usr/share/containers/oci/hooks.d"
+    pids_limit = 2048
+    container_exits_dir = "/var/run/kpod/exits"
+  [crio.image]
+    default_transport = "docker://"
+    pause_image = "kubernetes/pause"
+    pause_command = "/pause"
+    signature_policy = ""
+    image_volumes = "mkdir"
+  [crio.network]
+    network_dir = "/etc/cni/net.d/"
+    plugin_dir = "/opt/cni/bin/"