Allow to choose hostname and FQDN to be lowercased or not

.changelog/236.txt

@@ -0,0 +1,3 @@
+```release-note:enhancement
+Allow to choose hostname and FQDN to be lowercased or not
+```

internal/registry/registry.go

@@ -41,7 +41,8 @@ type ProcessProvider interface {
 }
 
 type ProviderOptions struct {
-	Hostfs string
+	Hostfs        string
+	LowerHostname bool
 }
 
 var (

providers/aix/host_aix_ppc64.go

@@ -34,6 +34,7 @@ import (
 	"errors"
 	"fmt"
 	"os"
+	"strings"
 	"time"
 
 	"github.com/elastic/go-sysinfo/internal/registry"
@@ -45,18 +46,27 @@ import (
 // As cgo will return some psinfo's fields with *byte, binary.Read will refuse this type.
 
 func init() {
-	registry.Register(aixSystem{})
+	// register wrappers that implement the HostFS versions of the ProcessProvider and HostProvider
+	registry.Register(func(opts registry.ProviderOptions) registry.HostProvider {
+		return aixSystem{lowerHostname: opts.LowerHostname}
+	})
+	registry.Register(func(opts registry.ProviderOptions) registry.ProcessProvider {
+		return aixSystem{lowerHostname: opts.LowerHostname}
+	})
 }
 
-type aixSystem struct{}
+type aixSystem struct {
+	lowerHostname bool
+}
 
 // Host returns a new AIX host.
-func (aixSystem) Host() (types.Host, error) {
-	return newHost()
+func (a aixSystem) Host() (types.Host, error) {
+	return newHost(a.lowerHostname)
 }
 
 type host struct {
-	info types.HostInfo
+	info          types.HostInfo
+	lowerHostname bool
 }
 
 // Architecture returns the architecture of the host
@@ -69,7 +79,7 @@ func (h *host) Info() types.HostInfo {
 	return h.info
 }
 
-// Info returns the current CPU usage of the host.
+// CPUTime returns the current CPU usage of the host.
 func (*host) CPUTime() (types.CPUTimes, error) {
 	clock := uint64(C.sysconf(C._SC_CLK_TCK))
 	tick2nsec := func(val uint64) uint64 {
@@ -127,16 +137,21 @@ func (*host) Memory() (*types.HostMemoryInfo, error) {
 }
 
 func (h *host) FQDNWithContext(ctx context.Context) (string, error) {
-	return shared.FQDNWithContext(ctx)
+	fqdn, err := shared.FQDNWithContext(ctx)
+	if h.lowerHostname {
+		fqdn = strings.ToLower(fqdn)
+	}
+
+	return fqdn, err
 }
 
 func (h *host) FQDN() (string, error) {
 	return h.FQDNWithContext(context.Background())
 }
 
-func newHost() (*host, error) {
-	h := &host{}
-	r := &reader{}
+func newHost(lowerHostname bool) (*host, error) {
+	h := &host{lowerHostname: lowerHostname}
+	r := &reader{lowerHostname: lowerHostname}
 	r.architecture(h)
 	r.bootTime(h)
 	r.hostname(h)
@@ -149,7 +164,8 @@ func newHost() (*host, error) {
 }
 
 type reader struct {
-	errs []error
+	errs          []error
+	lowerHostname bool
 }
 
 func (r *reader) addErr(err error) bool {
@@ -190,6 +206,10 @@ func (r *reader) hostname(h *host) {
 	if r.addErr(err) {
 		return
 	}
+
+	if r.lowerHostname {
+		v = strings.ToLower(v)
+	}
 	h.info.Hostname = v
 }
 

providers/aix/process_aix_ppc64.go

@@ -35,7 +35,6 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"strconv"
@@ -77,8 +76,8 @@ func (aixSystem) Process(pid int) (types.Process, error) {
 }
 
 // Self returns the current process.
-func (s aixSystem) Self() (types.Process, error) {
-	return s.Process(os.Getpid())
+func (a aixSystem) Self() (types.Process, error) {
+	return a.Process(os.Getpid())
 }
 
 type process struct {

providers/darwin/host_darwin.go

@@ -24,6 +24,7 @@ import (
 	"errors"
 	"fmt"
 	"os"
+	"strings"
 	"time"
 
 	"github.com/elastic/go-sysinfo/internal/registry"
@@ -32,17 +33,26 @@ import (
 )
 
 func init() {
-	registry.Register(darwinSystem{})
+	// register wrappers that implement the HostFS versions of the ProcessProvider and HostProvider
+	registry.Register(func(opts registry.ProviderOptions) registry.HostProvider {
+		return darwinSystem{lowerHostname: opts.LowerHostname}
+	})
+	registry.Register(func(opts registry.ProviderOptions) registry.ProcessProvider {
+		return darwinSystem{lowerHostname: opts.LowerHostname}
+	})
 }
 
-type darwinSystem struct{}
+type darwinSystem struct {
+	lowerHostname bool
+}
 
 func (s darwinSystem) Host() (types.Host, error) {
-	return newHost()
+	return newHost(s.lowerHostname)
 }
 
 type host struct {
-	info types.HostInfo
+	info          types.HostInfo
+	lowerHostname bool
 }
 
 func (h *host) Info() types.HostInfo {
@@ -138,7 +148,12 @@ func (h *host) Memory() (*types.HostMemoryInfo, error) {
 }
 
 func (h *host) FQDNWithContext(ctx context.Context) (string, error) {
-	return shared.FQDNWithContext(ctx)
+	fqdn, err := shared.FQDNWithContext(ctx)
+	if h.lowerHostname {
+		fqdn = strings.ToLower(fqdn)
+	}
+
+	return fqdn, err
 }
 
 func (h *host) FQDN() (string, error) {
@@ -160,9 +175,9 @@ func (h *host) LoadAverage() (*types.LoadAverageInfo, error) {
 	}, nil
 }
 
-func newHost() (*host, error) {
-	h := &host{}
-	r := &reader{}
+func newHost(lowerHostname bool) (*host, error) {
+	h := &host{lowerHostname: lowerHostname}
+	r := &reader{lowerHostname: lowerHostname}
 	r.architecture(h)
 	r.nativeArchitecture(h)
 	r.bootTime(h)
@@ -176,7 +191,8 @@ func newHost() (*host, error) {
 }
 
 type reader struct {
-	errs []error
+	errs          []error
+	lowerHostname bool
 }
 
 func (r *reader) addErr(err error) bool {
@@ -225,6 +241,10 @@ func (r *reader) hostname(h *host) {
 	if r.addErr(err) {
 		return
 	}
+
+	if r.lowerHostname {
+		v = strings.ToLower(v)
+	}
 	h.info.Hostname = v
 }
 

providers/linux/host_fqdn_integration_docker_linux_test.go

@@ -28,8 +28,41 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
+func TestHost_hostname(t *testing.T) {
+	testCases := []struct {
+		name      string
+		want      string
+		lowercase bool
+	}{
+		{
+			name:      "hostname",
+			want:      "hostName",
+			lowercase: false,
+		},
+		{
+			name:      "lowercase hostname",
+			want:      "hostname",
+			lowercase: true,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			host, err := newLinuxSystem("", tc.lowercase).Host()
+			if err != nil {
+				t.Fatalf("could not get host info: %v\n", err)
+			}
+
+			got := host.Info()
+			if got.Hostname != tc.want {
+				t.Errorf("got hostname %q; want hostname %q",
+					got.Hostname, tc.want)
+			}
+		})
+	}
+}
 func TestHost_FQDN_set(t *testing.T) {
-	host, err := newLinuxSystem("").Host()
+	host, err := newLinuxSystem("", false).Host()
 	if err != nil {
 		t.Fatal(fmt.Errorf("could not get host information: %w", err))
 	}
@@ -45,7 +78,7 @@ func TestHost_FQDN_set(t *testing.T) {
 }
 
 func TestHost_FQDN_not_set(t *testing.T) {
-	host, err := newLinuxSystem("").Host()
+	host, err := newLinuxSystem("", false).Host()
 	if err != nil {
 		t.Fatal(fmt.Errorf("could not get host information: %w", err))
 	}

providers/linux/host_fqdn_integration_linux_test.go

@@ -31,12 +31,13 @@ import (
 )
 
 const (
-	wantHostname = "hostname"
-	wantDomain   = "some.domain"
-	wantFQDN     = wantHostname + "." + wantDomain
+	wantHostnameMixedCase = "hostName"
+	wantHostname          = "hostname"
+	wantDomain            = "some.domain"
+	wantFQDN              = wantHostname + "." + wantDomain
 )
 
-func TestHost_FQDN(t *testing.T) {
+func TestHost_Docker(t *testing.T) {
 	if _, err := execabs.LookPath("docker"); err != nil {
 		t.Skipf("Skipping because docker was not found: %v", err)
 	}
@@ -77,6 +78,16 @@ func TestHost_FQDN(t *testing.T) {
 				"./providers/linux",
 			},
 		},
+		{
+			name:     "TestHost_hostname",
+			Hostname: wantHostnameMixedCase,
+			Cmd: []string{
+				"go", "test", "-v", "-count", "1",
+				"-tags", "integration,docker",
+				"-run", "^TestHost_FQDN_not_set$",
+				"./providers/linux",
+			},
+		},
 	}
 
 	for _, tc := range tcs {