Implement GET /logs endpoint for APIv4 (#5778)

6 files changed, 89 insertions, 7 deletions

diff --git a/api/admin.go b/api/admin.go
index 14c355701..59890c739 100644
--- a/api/admin.go
+++ b/api/admin.go
@@ -46,7 +46,7 @@ func InitAdmin() {
 }
 
 func getLogs(c *Context, w http.ResponseWriter, r *http.Request) {
-	lines, err := app.GetLogs()
+	lines, err := app.GetLogs(0, 100000)
 	if err != nil {
 		c.Err = err
 		return
diff --git a/api4/system.go b/api4/system.go
index d33be0c66..f12d802ef 100644
--- a/api4/system.go
+++ b/api4/system.go
@@ -21,6 +21,8 @@ func InitSystem() {
 	BaseRoutes.ApiRoot.Handle("/email/test", ApiSessionRequired(testEmail)).Methods("POST")
 	BaseRoutes.ApiRoot.Handle("/database/recycle", ApiSessionRequired(databaseRecycle)).Methods("POST")
 	BaseRoutes.ApiRoot.Handle("/caches/invalidate", ApiSessionRequired(invalidateCaches)).Methods("POST")
+
+	BaseRoutes.ApiRoot.Handle("/logs", ApiSessionRequired(getLogs)).Methods("GET")
 }
 
 func getSystemPing(c *Context, w http.ResponseWriter, r *http.Request) {
@@ -94,3 +96,18 @@ func invalidateCaches(c *Context, w http.ResponseWriter, r *http.Request) {
 	w.Header().Set("Cache-Control", "no-cache, no-store, must-revalidate")
 	ReturnStatusOK(w)
 }
+
+func getLogs(c *Context, w http.ResponseWriter, r *http.Request) {
+	if !app.SessionHasPermissionTo(c.Session, model.PERMISSION_MANAGE_SYSTEM) {
+		c.SetPermissionError(model.PERMISSION_MANAGE_SYSTEM)
+		return
+	}
+
+	lines, err := app.GetLogs(c.Params.Page, c.Params.PerPage)
+	if err != nil {
+		c.Err = err
+		return
+	}
+
+	w.Write([]byte(model.ArrayToJson(lines)))
+}
diff --git a/api4/system_test.go b/api4/system_test.go
index 4da91f428..80b4996ca 100644
--- a/api4/system_test.go
+++ b/api4/system_test.go
@@ -4,6 +4,7 @@ import (
 	"strings"
 	"testing"
 
+	l4g "github.com/alecthomas/log4go"
 	"github.com/mattermost/platform/model"
 	"github.com/mattermost/platform/utils"
 )
@@ -145,3 +146,43 @@ func TestInvalidateCaches(t *testing.T) {
 		t.Fatal("should clean the cache")
 	}
 }
+
+func TestGetLogs(t *testing.T) {
+	th := Setup().InitBasic().InitSystemAdmin()
+	defer TearDown()
+	Client := th.Client
+
+	for i := 0; i < 20; i++ {
+		l4g.Info(i)
+	}
+
+	logs, resp := th.SystemAdminClient.GetLogs(0, 10)
+	CheckNoError(t, resp)
+
+	if len(logs) != 10 {
+		t.Log(len(logs))
+		t.Fatal("wrong length")
+	}
+
+	logs, resp = th.SystemAdminClient.GetLogs(1, 10)
+	CheckNoError(t, resp)
+
+	if len(logs) != 10 {
+		t.Log(len(logs))
+		t.Fatal("wrong length")
+	}
+
+	logs, resp = th.SystemAdminClient.GetLogs(-1, -1)
+	CheckNoError(t, resp)
+
+	if len(logs) != 0 {
+		t.Fatal("should not be empty")
+	}
+
+	_, resp = Client.GetLogs(0, 10)
+	CheckForbiddenStatus(t, resp)
+
+	Client.Logout()
+	_, resp = Client.GetLogs(0, 10)
+	CheckUnauthorizedStatus(t, resp)
+}
diff --git a/app/admin.go b/app/admin.go
index c551da50c..509d81840 100644
--- a/app/admin.go
+++ b/app/admin.go
@@ -18,14 +18,14 @@ import (
 	"github.com/mattermost/platform/utils"
 )
 
-func GetLogs() ([]string, *model.AppError) {
-	lines, err := GetLogsSkipSend()
+func GetLogs(page, perPage int) ([]string, *model.AppError) {
+	lines, err := GetLogsSkipSend(page, perPage)
 	if err != nil {
 		return nil, err
 	}
 
 	if einterfaces.GetClusterInterface() != nil {
-		clines, err := einterfaces.GetClusterInterface().GetLogs()
+		clines, err := einterfaces.GetClusterInterface().GetLogs(page, perPage)
 		if err != nil {
 			return nil, err
 		}
@@ -36,7 +36,7 @@ func GetLogs() ([]string, *model.AppError) {
 	return lines, nil
 }
 
-func GetLogsSkipSend() ([]string, *model.AppError) {
+func GetLogsSkipSend(page, perPage int) ([]string, *model.AppError) {
 	var lines []string
 
 	if utils.Cfg.LogSettings.EnableFile {
@@ -47,9 +47,20 @@ func GetLogsSkipSend() ([]string, *model.AppError) {
 
 		defer file.Close()
 
+		offsetCount := 0
+		limitCount := 0
 		scanner := bufio.NewScanner(file)
 		for scanner.Scan() {
-			lines = append(lines, scanner.Text())
+			if limitCount >= perPage {
+				break
+			}
+
+			if offsetCount >= page*perPage {
+				lines = append(lines, scanner.Text())
+				limitCount++
+			} else {
+				offsetCount++
+			}
 		}
 	} else {
 		lines = append(lines, "")
diff --git a/einterfaces/cluster.go b/einterfaces/cluster.go
index b7ba55144..1c6b1e071 100644
--- a/einterfaces/cluster.go
+++ b/einterfaces/cluster.go
@@ -23,7 +23,7 @@ type ClusterInterface interface {
 	InvalidateCacheForReactions(postId string)
 	Publish(event *model.WebSocketEvent)
 	UpdateStatus(status *model.Status)
-	GetLogs() ([]string, *model.AppError)
+	GetLogs(page, perPage int) ([]string, *model.AppError)
 	GetClusterId() string
 	ConfigChanged(previousConfig *model.Config, newConfig *model.Config, sendToOtherServer bool) *model.AppError
 	InvalidateAllCaches() *model.AppError
diff --git a/model/client4.go b/model/client4.go
index 6e862a1db..a2878df6f 100644
--- a/model/client4.go
+++ b/model/client4.go
@@ -1604,3 +1604,16 @@ func (c *Client4) UploadBrandImage(data []byte) (bool, *Response) {
 		return CheckStatusOK(rp), BuildResponse(rp)
 	}
 }
+
+// Logs Section
+
+// GetLogs page of logs as a string array.
+func (c *Client4) GetLogs(page, perPage int) ([]string, *Response) {
+	query := fmt.Sprintf("?page=%v&per_page=%v", page, perPage)
+	if r, err := c.DoApiGet("/logs"+query, ""); err != nil {
+		return nil, &Response{StatusCode: r.StatusCode, Error: err}
+	} else {
+		defer closeBody(r)
+		return ArrayFromJson(r.Body), BuildResponse(r)
+	}
+}