EH: Add qconf resolve host group (#23)

* EH: Watch qacct file; improved types

* EH: Add qconf host group resolving call

Author: dgruber

pkg/qconf/v9.0/qconf.go

@@ -68,6 +68,7 @@ type QConf interface {
 	ModifyHostGroup(hostGroupName string, hg HostGroupConfig) error
 	DeleteHostGroup(groupName string) error
 	ShowHostGroup(groupName string) (HostGroupConfig, error)
+	ShowHostGroupResolved(groupName string) ([]string, error)
 	ShowHostGroups() ([]string, error)
 
 	AddResourceQuotaSet(rqs ResourceQuotaSetConfig) error

pkg/qconf/v9.0/qconf_impl.go

@@ -46,6 +46,9 @@ type CommandLineQConfConfig struct {
 
 // NewCommandLineQConf creates a new instance of CommandLineQConf.
 func NewCommandLineQConf(config CommandLineQConfConfig) (*CommandLineQConf, error) {
+	if config.Executable == "" {
+		config.Executable = "qconf"
+	}
 	return &CommandLineQConf{config: config}, nil
 }
 
@@ -122,7 +125,6 @@ func (c *CommandLineQConf) GetClusterConfiguration() (ClusterConfig, error) {
 		if err != nil {
 			return cc, fmt.Errorf("failed to read host config: %v", err)
 		}
-
 		cc.HostConfigurations[host] = hc
 	}
 
@@ -1115,7 +1117,9 @@ func (c *CommandLineQConf) DeleteHostGroup(groupName string) error {
 	return err
 }
 
-// ShowHostGroup shows the specified host group.
+// ShowHostGroup shows the host list of a particular host group. The host
+// list can contain other host groups. Use ShowHowGroupResolved() for
+// getting a list of all hosts.
 func (c *CommandLineQConf) ShowHostGroup(groupName string) (HostGroupConfig, error) {
 	out, err := c.RunCommand("-shgrp", groupName)
 	if err != nil {
@@ -1139,6 +1143,15 @@ func (c *CommandLineQConf) ShowHostGroup(groupName string) (HostGroupConfig, err
 	return cfg, nil
 }
 
+// ShowHostGroupResolved shows all hosts in a host group and all sub-groups.
+func (c *CommandLineQConf) ShowHostGroupResolved(groupName string) ([]string, error) {
+	out, err := c.RunCommand("-shgrp_resolved", groupName)
+	if err != nil {
+		return nil, err
+	}
+	return splitWithoutEmptyLines(out, "\n"), nil
+}
+
 // ShowHostGroups shows all host groups.
 func (c *CommandLineQConf) ShowHostGroups() ([]string, error) {
 	output, err := c.RunCommand("-shgrpl")

pkg/qconf/v9.0/qconf_impl_test.go

@@ -699,7 +699,12 @@ gid_range                    20000-20100`, "\n")
 			Expect(groups).NotTo(BeNil())
 			Expect(groups).To(ContainElement(groupName))
 
-			// Show the specific host group configuration and verify its details
+			// Show a list of all hosts in the host group
+			hosts, err := qc.ShowHostGroupResolved(groupName)
+			Expect(err).To(BeNil())
+			Expect(hosts).NotTo(BeNil())
+			Expect(hosts).To(ContainElement("master"))
+
 			retrievedHostGroupConfig, err := qc.ShowHostGroup(groupName)
 			Expect(err).To(BeNil())
 			Expect(retrievedHostGroupConfig).To(Equal(hostGroupConfig))
@@ -1157,7 +1162,8 @@ gid_range                    20000-20100`, "\n")
 		var err error
 
 		BeforeEach(func() {
-			qc, err = qconf.NewCommandLineQConf(qconf.CommandLineQConfConfig{Executable: "qconf"})
+			qc, err = qconf.NewCommandLineQConf(
+				qconf.CommandLineQConfConfig{Executable: "qconf"})
 			Expect(err).To(BeNil())
 		})