Introduce drun command, refactor code to use context package

11 files changed, 0 insertions, 1092 deletions

diff --git a/internal/fs/catfile.go b/internal/fs/catfile.go
deleted file mode 100644
index 99f521f..0000000
--- a/internal/fs/catfile.go
+++ /dev/null
@@ -1,27 +0,0 @@
-package fs
-
-import "sync"
-
-// CatFile is for reading a whole file.
-type CatFile struct {
-	readFile
-}
-
-// NewCatFile returns a new file catter.
-func NewCatFile(filePath string, globID string, serverMessages chan<- string, limiter chan struct{}) CatFile {
-	var mutex sync.Mutex
-
-	return CatFile{
-		readFile: readFile{
-			filePath:       filePath,
-			stop:           make(chan struct{}),
-			globID:         globID,
-			serverMessages: serverMessages,
-			retry:          false,
-			canSkipLines:   false,
-			seekEOF:        false,
-			limiter:        limiter,
-			mutex:          &mutex,
-		},
-	}
-}
diff --git a/internal/fs/filereader.go b/internal/fs/filereader.go
deleted file mode 100644
index 5a08e27..0000000
--- a/internal/fs/filereader.go
+++ /dev/null
@@ -1,9 +0,0 @@
-package fs
-
-// FileReader is the interface used on the dtail server to read/cat/grep/mapr... a file.
-type FileReader interface {
-	Start(lines chan<- LineRead, regex string) error
-	FilePath() string
-	Retry() bool
-	Stop()
-}
diff --git a/internal/fs/lineread.go b/internal/fs/lineread.go
deleted file mode 100644
index 7ee558e..0000000
--- a/internal/fs/lineread.go
+++ /dev/null
@@ -1,28 +0,0 @@
-package fs
-
-import (
-	"fmt"
-)
-
-// LineRead represents a read log line.
-type LineRead struct {
-	// The content of the log line.
-	Content []byte
-	// Until now, how many log lines were processed?
-	Count uint64
-	// Sometimes we produce too many log lines so that the client
-	// is too slow to process all of them. The server will drop log
-	// lines if that happens but it will signal to the client how
-	// many log lines in % could be transmitted to the client.
-	TransmittedPerc int
-	GlobID          *string
-}
-
-// Return a human readable representation of the followed line.
-func (l LineRead) String() string {
-	return fmt.Sprintf("LineRead(Content:%s,TransmittedPerc:%v,Count:%v,GlobID:%s)",
-		string(l.Content),
-		l.TransmittedPerc,
-		l.Count,
-		*l.GlobID)
-}
diff --git a/internal/fs/permissions/permission.go b/internal/fs/permissions/permission.go
deleted file mode 100644
index 6e83309..0000000
--- a/internal/fs/permissions/permission.go
+++ /dev/null
@@ -1,14 +0,0 @@
-// +build !linux
-
-package permissions
-
-import (
-	"github.com/mimecast/dtail/internal/logger"
-)
-
-// ToRead is to check whether user has read permissions to a given file.
-func ToRead(user, filePath string) (bool, error) {
-	// Only implemented for Linux, always expect true
-	logger.Warn(user, filePath, "Not performing ACL check, not supported on this platform")
-	return true, nil
-}
diff --git a/internal/fs/permissions/permission_linux.c b/internal/fs/permissions/permission_linux.c
deleted file mode 100644
index cd10525..0000000
--- a/internal/fs/permissions/permission_linux.c
+++ /dev/null
@@ -1,395 +0,0 @@
-#include "permission_linux.h"
-
-#ifdef DEBUG
-void debug_print_checker(struct permission_checker *pc) {
-    fprintf(stderr, "DEBUG: user_name:%s (%d)\n",
-        pc->user_name, pc->uid);
-
-    fprintf(stderr, "DEBUG: ngids:%d\n", pc->ngids);
-    int j;
-    for (j = 0; j < pc->ngids; j++) {
-        fprintf(stderr, "DEBUG: %d", pc->gids[j]);
-        struct group *gr = getgrgid(pc->gids[j]);
-        if (gr != NULL)
-            fprintf(stderr, " (%s)", gr->gr_name);
-        fprintf(stderr, "\n");
-    }
-
-    fprintf(stderr, "DEBUG: file_path:%s (%d:%d)\n",
-            pc->file_path, pc->file_stat.st_uid, pc->file_stat.st_gid);
-}
-#endif // DEBUG
-
-int stat_file(struct permission_checker *pc) {
-    if (stat(pc->file_path, &pc->file_stat) != 0)
-      return -1;
-
-#ifdef DEBUG
-        fprintf(stderr, "DEBUG: File'%s' is owned by '%d:%d'\n",
-                pc->file_path, pc->file_stat.st_uid, pc->file_stat.st_gid);
-#endif
-
-    return 0;
-}
-
-int get_user_uid(struct permission_checker *pc) {
-    struct passwd *result = NULL;
-
-    size_t bufsize = sysconf(_SC_GETPW_R_SIZE_MAX);
-    if (bufsize == -1)
-        bufsize = 16384;
-
-    char *buf = malloc(bufsize);
-    if (buf == NULL) {
-#ifdef DEBUG
-        fprintf(stderr, "DEBUG: Unabel to allocate bufer while retrieving user '%s'\n", pc->user_name);
-#endif
-        return -1;
-    }
-
-    int rc = getpwnam_r(pc->user_name, &pc->pw, buf, bufsize, &result);
-
-    if (result == NULL) {
-#ifdef DEBUG
-        if (rc == 0) {
-            fprintf(stderr, "DEBUG: No user '%s' found\n", pc->user_name);
-        } else {
-            fprintf(stderr, "DEBUG: Unknown error while retrieving user '%s'\n", pc->user_name);
-        }
-#endif
-
-        free(buf);
-        return -1;
-    }
-
-    pc->uid = pc->pw.pw_uid;
-
-    free(buf);
-    return 0;
-}
-
-int get_user_groups(struct permission_checker *pc) {
-    // First assume we are in 10 groups max
-    pc->ngids = 10;
-    pc->gids = malloc(pc->ngids * sizeof(gid_t));
-
-    if (pc->gids == NULL) {
-#ifdef DEBUG
-        fprintf(stderr, "DEBUG: Unable to allocate space for gids.");
-#endif
-        return -1;
-    }
-
-    // Try so many times to load group list until it fits into group array.
-    while (getgrouplist(pc->user_name, pc->pw.pw_gid, pc->gids, &pc->ngids) == -1) {
-        // Too many groups, enlarge group array and try again
-        int newngids = pc->ngids + 100;
-        size_t newsize = newngids * sizeof(gid_t);
-
-        if (SIZE_MAX / newngids < sizeof(gid_t)) {
-            // Overflow
-#ifdef DEBUG
-            fprintf(stderr, "DEBUG: Overflow detected.");
-#endif
-            return -1;
-        }
-
-        gid_t *newgids = realloc(pc->gids, newsize);
-        if (newgids == NULL) {
-#ifdef DEBUG
-            fprintf(stderr, "DEBUG: Unable to allocate space for gids.");
-#endif
-            free(pc->gids);
-            return -1;
-        }
-
-        pc->gids = newgids;
-        pc->ngids = newngids;
-    }
-
-    return 0;
-}
-
-int is_member_of_group(struct permission_checker *pc, gid_t gid) {
-    int j;
-    for (j = 0; j < pc->ngids; j++)
-        if (pc->gids[j] == gid)
-            return 1;
-    return 0;
-}
-
-int check_acl_uid_matches(uid_t uid, acl_entry_t entry) {
-    int ret = -1;
-    uid_t *acl_uid = acl_get_qualifier(entry);
-    if (acl_uid == NULL) {
-#ifdef DEBUG
-        fprintf(stderr, "DEBUG: Unable to retrieve user uid from ACL entry");
-#endif
-        return -1;
-    }
-
-    ret = *acl_uid == uid ? 0 : -1;
-#ifdef DEBUG
-    fprintf(stderr, "DEBUG: ACL user match?: %d <=> %d: %d\n", *acl_uid, uid, ret);
-#endif
-    acl_free(acl_uid);
-    return ret;
-}
-
-int check_acl_gid_matches(gid_t *gids, int ngids, acl_entry_t entry) {
-    int ret = -1;
-    gid_t *acl_gid = acl_get_qualifier(entry);
-    if (acl_gid == NULL) {
-#ifdef DEBUG
-        fprintf(stderr, "DEBUG: Unable to retrieve user uid from ACL entry");
-#endif
-        return -1;
-    }
-
-    int j;
-    for (j = 0; j < ngids; j++) {
-        if (*acl_gid == gids[j]) {
-#ifdef DEBUG
-            fprintf(stderr, "DEBUG: User is in group %d", *acl_gid);
-#endif
-            ret = 0;
-            break;
-        }
-    }
-
-#ifdef DEBUG
-    fprintf(stderr, "DEBUG: ACL group match?: %d <=> ...: %d\n", *acl_gid, ret);
-#endif
-    acl_free(acl_gid);
-    return ret;
-}
-
-int check_acl(struct permission_checker *pc, const int flag) {
-    // By default user has no read perm.
-    int has_read_perm = 0;
-
-    // By default mask tells that there are read perm. However in order to have
-    // read permissions both, has_read_perm and mask_allows_read_access must be 1!
-    int mask_allows_read_access = 1;
-
-    acl_type_t type = ACL_TYPE_ACCESS;
-    acl_t acl = acl_get_file(pc->file_path, type);
-
-    if (acl == NULL)
-        // Unable to retrieve ACL.
-        return -1;
-
-    // Walk through each entry of this ACL.
-    int id;
-    for (id = ACL_FIRST_ENTRY; ; id = ACL_NEXT_ENTRY) {
-        acl_entry_t entry;
-        if (acl_get_entry(acl, id, &entry) != 1)
-            // No more ACL entries.
-            break;
-
-        acl_tag_t tag;
-        if (acl_get_tag_type(entry, &tag) == -1)
-            // Unable to retrieve ACL tag.
-            return -1;
-
-        switch (tag) {
-            case ACL_USER_OBJ:
-                if (flag == GROUP_CHECK)
-                    continue;
-#ifdef DEBUG
-                fprintf(stderr, "DEBUG: ACL_USER_OBJ\n");
-#endif
-                // Ignore this ACL entry if user is not owner of file.
-                if (pc->uid != pc->file_stat.st_uid)
-                    continue;
-                break;
-            case ACL_USER:
-                if (flag == GROUP_CHECK)
-                    continue;
-#ifdef DEBUG
-                fprintf(stderr, "DEBUG: ACL_USER\n");
-#endif
-                // Ignore this ACL entry if uid does not match.
-                if (check_acl_uid_matches(pc->uid, entry) != 0)
-                    continue;
-                break;
-            case ACL_GROUP_OBJ:
-                if (flag == USER_CHECK)
-                    continue;
-#ifdef DEBUG
-                fprintf(stderr, "DEBUG: ACL_GROUP_OBJ\n");
-#endif
-                // Ignore ACL entry if user is not in group of file.
-                if (!is_member_of_group(pc, pc->file_stat.st_gid))
-                    continue;
-                break;
-            case ACL_GROUP:
-                if (flag == USER_CHECK)
-                    continue;
-#ifdef DEBUG
-                fprintf(stderr, "DEBUG: ACL_GROUP\n");
-#endif
-                // Ignore ACL entry if user is not in group of entry.
-                if (check_acl_gid_matches(pc->gids, pc->ngids, entry) != 0)
-                    continue;
-                break;
-            case ACL_OTHER:
-                if (flag == GROUP_CHECK)
-                    continue;
-#ifdef DEBUG
-                fprintf(stderr, "DEBUG: ACL_OTHER\n");
-#endif
-                break;
-            case ACL_MASK:
-#ifdef DEBUG
-                fprintf(stderr, "DEBUG: ACL_MASK\n");
-#endif
-                break;
-            default:
-#ifdef DEBUG
-                fprintf(stderr, "DEBUG: Unknown ACL tag\n");
-#endif
-                return -1;
-        }
-
-#ifdef DEBUG
-        fprintf(stderr, "DEBUG: Retrieving permset\n");
-#endif
-        acl_permset_t permset;
-        int permission;
-        if (acl_get_permset(entry, &permset) == -1)
-            // Unable to retrieve permset.
-            return -1;
-
-        if ((permission = acl_get_perm(permset, ACL_READ)) == -1)
-            // Unable to retrieve permset value.
-            return -1;
-
-        if (permission == 1 && tag != ACL_MASK) {
-#ifdef DEBUG
-            fprintf(stderr, "DEBUG: ACL says user has permission to read file.\n");
-#endif
-            has_read_perm = 1;
-        } else if (permission == 0 && tag == ACL_MASK)  {
-            // Mask says that there are no permissions to read.
-            mask_allows_read_access = 0;
-#ifdef DEBUG
-            fprintf(stderr, "DEBUG: ACL mask says no permission to read file.\n");
-#endif
-        }
-    }
-
-    if (has_read_perm && mask_allows_read_access) {
-#ifdef DEBUG
-        fprintf(stderr, "DEBUG: ACL end result: User has permission to read file.\n");
-#endif
-        return 1;
-    }
-
-#ifdef DEBUG
-    fprintf(stderr, "DEBUG: ACL end result: User has no permission to read file.\n");
-#endif
-    return 0;
-}
-
-int check_traditional(struct permission_checker *pc, const int flag) {
-    mode_t mode = pc->file_stat.st_mode;
-    uid_t uid = pc->file_stat.st_uid;
-    gid_t gid = pc->file_stat.st_gid;
-
-    if (flag == USER_CHECK && (mode & S_IROTH)) {
-#ifdef DEBUG
-        fprintf(stderr, "DEBUG: Others can read file '%s'\n",
-                pc->file_path);
-#endif
-        return 1;
-
-    } else if (flag == USER_CHECK && (mode & S_IRUSR) && uid == pc->uid) {
-#ifdef DEBUG
-        fprintf(stderr, "DEBUG: User '%s' can read file '%s'\n",
-                pc->user_name, pc->file_path);
-#endif
-        return 1;
-
-    } else if (flag == GROUP_CHECK && (mode & S_IRGRP) && is_member_of_group(pc, gid)) {
-#ifdef DEBUG
-        fprintf(stderr, "DEBUG: User's '%s' group can read file '%s'\n",
-                pc->user_name, pc->file_path);
-#endif
-        return 1;
-    }
-
-    return 0;
-}
-
-int permission_to_read(char* user_name, char *file_path) {
-    int rc = -1;
-
-#ifdef DEBUG
-    fprintf(stderr, "DEBUG: User check '%s' for file '%s'\n", user_name, file_path);
-#endif
-    struct permission_checker pc = {
-        .user_name = user_name,
-        .gids = NULL,
-        .ngids = 0,
-        .file_path = file_path,
-    };
-
-    // Gather user's UID.
-    if ((rc = get_user_uid(&pc)) == -1)
-        // Could not retrieve UID.
-        goto cleanup;
-
-    // Gather file owner (user and group).
-    if ((rc = stat_file(&pc)) == -1)
-        // Could not stat file.
-        goto cleanup;
-
-    // Check whether there is an ACL entry which would allow the user
-    // to read the file. Don't check for any groups yet. The issue with
-    // groups is that it can be very slow to retrieve the list of groups
-    // of a specific user when done via a remote LDAP server!
-    if ((rc = check_acl(&pc, USER_CHECK)) == 1)
-        // Yes, has permissions.
-        goto cleanup;
-
-    // Check whether ACLs of file could be retrieved.
-    if (rc == -1) {
-        if (errno != ENOTSUP)
-            // Unknown error.
-            goto cleanup;
-
-        // File system does not support ACLs.
-        // Fallback to traditional permissions.
-        if ((rc = check_traditional(&pc, USER_CHECK)) == 1)
-            // Yes, has traditional permissions.
-            goto cleanup;
-
-        if ((rc = get_user_groups(&pc)) == -1)
-            // Can not retrieve user's groups.
-            goto cleanup;
-
-        rc = check_traditional(&pc, GROUP_CHECK);
-        goto cleanup;
-    }
-
-    if ((rc = get_user_groups(&pc)) == -1)
-        // Can not retrieve use'r groups.
-        goto cleanup;
-
-    // Check whether there is an ACL entry which would allow any of the
-    // user's groups to read the file.
-    rc = check_acl(&pc, GROUP_CHECK);
-
-cleanup:
-#ifdef DEBUG
-    debug_print_checker(&pc);
-#endif
-
-    if (pc.ngids)
-        free(pc.gids);
-
-    return rc;
-}
-
-// vim: set tabstop=8 softtabstop=0 expandtab shiftwidth=4 smarttab
diff --git a/internal/fs/permissions/permission_linux.go b/internal/fs/permissions/permission_linux.go
deleted file mode 100644
index feae729..0000000
--- a/internal/fs/permissions/permission_linux.go
+++ /dev/null
@@ -1,33 +0,0 @@
-package permissions
-
-/*
-#include "permission_linux.h"
-#cgo LDFLAGS: -L. -lacl
-*/
-import "C"
-
-import (
-	"errors"
-	"unsafe"
-)
-
-// To check whether user has Linux file system permissions to read a given file.
-func ToRead(user, filePath string) (bool, error) {
-	cUser := C.CString(user)
-	cFilePath := C.CString(filePath)
-
-	defer C.free(unsafe.Pointer(cUser))
-	defer C.free(unsafe.Pointer(cFilePath))
-
-	cOk, err := C.permission_to_read(cUser, cFilePath)
-	if cOk == 1 {
-		return true, nil
-	}
-
-	if err != nil {
-		// err contains errno message
-		return false, err
-	}
-
-	return false, errors.New("User without permission to read file")
-}
diff --git a/internal/fs/permissions/permission_linux.h b/internal/fs/permissions/permission_linux.h
deleted file mode 100644
index a2c266e..0000000
--- a/internal/fs/permissions/permission_linux.h
+++ /dev/null
@@ -1,60 +0,0 @@
-#ifndef PERMISSION_LINUX_H
-#define PERMISSION_LINUX_H
-
-#include <acl/libacl.h>
-#include <errno.h>
-#include <grp.h>
-#include <pwd.h>
-#include <stdio.h>
-#include <stdint.h>
-#include <stdlib.h>
-#include <sys/acl.h>
-#include <sys/stat.h>
-#include <sys/types.h>
-#include <unistd.h>
-
-//#define DEBUG
-#define USER_CHECK 0
-#define GROUP_CHECK 1
-
-struct permission_checker {
-  char *user_name;
-  uid_t uid;
-  gid_t *gids;
-  int ngids;
-  char *file_path;
-  struct stat file_stat;
-  struct passwd pw;
-};
-
-
-#ifdef DEBUG
-// Print out permission_checker struct.
-void debug_print_checker(struct permission_checker *pc);
-#endif
-
-// Stat a given file to retrieve traditional UNIX permissions.
-int stat_file(struct permission_checker *pc);
-
-// Retrieve UID of user.
-int get_user_uid(struct permission_checker *pc);
-
-// Retrieve all groups of the user.
-int get_user_groups(struct permission_checker *pc);
-
-// Check whether user is member of a group or not.
-int is_member_of_group(struct permission_checker *pc, gid_t gid);
-
-// Check whether user can read file according Linux ACLs.
-// As flag use either USER_CHECK or GROUP_CHECK.
-int check_acl(struct permission_checker *pc, const int flag);
-
-// Check whether user has permissions to read file according traditional
-// UNIX permissions. As flag use either USER_CHECK or GROUP_CHECK.
-int check_traditional(struct permission_checker *pc, const int flag);
-
-// Returns 1 if user has permission to read file.
-// Returns <0 on error and returns 0 if no permissions.
-int permission_to_read(char* user, char *file_path);
-
-#endif // PERMISSION_LINUX_H
diff --git a/internal/fs/permissions/permission_test.go b/internal/fs/permissions/permission_test.go
deleted file mode 100644
index d415ac2..0000000
--- a/internal/fs/permissions/permission_test.go
+++ /dev/null
@@ -1,112 +0,0 @@
-// +build linux
-
-package permissions
-
-import (
-	"os"
-	"os/exec"
-	"os/user"
-	"strings"
-	"testing"
-)
-
-const (
-	setfacl string = "/usr/bin/setfacl"
-	file    string = "/tmp/acltest"
-)
-
-func TestLinuxACL(t *testing.T) {
-	setfacl := "/usr/bin/setfacl"
-	file := "/tmp/acltest"
-
-	// Delete file if it exists.
-	if _, err := os.Stat(file); err == nil {
-		os.Remove(file)
-	}
-
-	f, err := os.Create(file)
-	if err != nil {
-		t.Errorf("%v", err)
-	}
-	defer func() {
-		f.Close()
-		//os.Remove(file)
-	}()
-
-	user, err := user.Current()
-	if err != nil {
-		t.Errorf("Unable to retrieve current user: %v", err)
-	}
-
-	// Test 1: Remove all permissions and perform a permission check
-	cmd := exec.Command(setfacl, "-b", "-m", "u::---,g::---,o::---", file)
-	if err := cmd.Run(); err != nil {
-		t.Errorf("%s -> %v", strings.Join(cmd.Args, " "), err)
-	}
-	if ok, _ := ToRead(user.Username, file); ok {
-		t.Errorf("Didn't expect permissions to read file!")
-	}
-
-	// Test 2: Add read permission to file owner
-	cmd = exec.Command(setfacl, "-b", "-m", "u::r--,g::---,o::---", file)
-	if err := cmd.Run(); err != nil {
-		t.Errorf("%s -> %v", strings.Join(cmd.Args, " "), err)
-	}
-	if ok, err := ToRead(user.Username, file); !ok {
-		t.Errorf("Expected permissions to read file: %v", err)
-	}
-
-	// Test 3: Add read permission to file group
-	cmd = exec.Command(setfacl, "-b", "-m", "u::---,g::r--,o::---", file)
-	if err := cmd.Run(); err != nil {
-		t.Errorf("%s -> %v", strings.Join(cmd.Args, " "), err)
-	}
-	if ok, err := ToRead(user.Username, file); !ok {
-		t.Errorf("Expected permissions to read file: %v", err)
-	}
-
-	// Test 4: Add read permission to others
-	cmd = exec.Command(setfacl, "-b", "-m", "u::---,g::---,o::r--", file)
-	if err := cmd.Run(); err != nil {
-		t.Errorf("%s -> %v", strings.Join(cmd.Args, " "), err)
-	}
-
-	if ok, err := ToRead(user.Username, file); !ok {
-		t.Errorf("Expected permissions to read file: %v", err)
-	}
-
-	// Test 5: Remove read permission from mask
-	cmd = exec.Command(setfacl, "-m", "m::---", file)
-	if err := cmd.Run(); err != nil {
-		t.Errorf("%s -> %v", strings.Join(cmd.Args, " "), err)
-	}
-	if ok, _ := ToRead(user.Username, file); ok {
-		t.Errorf("Didn't expect permissions to read file!")
-	}
-	cmd = exec.Command(setfacl, "-m", "m::r--", file)
-	if err := cmd.Run(); err != nil {
-		t.Errorf("%s -> %v", strings.Join(cmd.Args, " "), err)
-	}
-
-	// Test 6: Add read permission to specific group
-	cmd = exec.Command(setfacl, "-b", "-m", "u::---,g:"+user.Username+":r--,o::---", file)
-	if err := cmd.Run(); err != nil {
-		t.Errorf("%s -> %v", strings.Join(cmd.Args, " "), err)
-	}
-	if ok, err := ToRead(user.Username, file); !ok {
-		t.Errorf("Expected permissions to read file for user %v: %v", user.Username, err)
-	}
-
-	// Test 7: Remove all permissions but mask
-	cmd = exec.Command(setfacl, "-b", "-m", "u::---,g::---,o::---", file)
-	if err := cmd.Run(); err != nil {
-		t.Errorf("%s -> %v", strings.Join(cmd.Args, " "), err)
-	}
-	cmd = exec.Command(setfacl, "-m", "m::r--", file)
-	if err := cmd.Run(); err != nil {
-		t.Errorf("%s -> %v", strings.Join(cmd.Args, " "), err)
-	}
-	if ok, _ := ToRead(user.Username, file); ok {
-		t.Errorf("Didn't expect permissions to read file!")
-	}
-}
diff --git a/internal/fs/readfile.go b/internal/fs/readfile.go
deleted file mode 100644
index 312447a..0000000
--- a/internal/fs/readfile.go
+++ /dev/null
@@ -1,318 +0,0 @@
-package fs
-
-import (
-	"bufio"
-	"compress/gzip"
-	"github.com/mimecast/dtail/internal/logger"
-	"errors"
-	"io"
-	"os"
-	"regexp"
-	"strings"
-	"sync"
-	"time"
-
-	"github.com/DataDog/zstd"
-)
-
-// Used to tail and filter a local log file.
-type readFile struct {
-	// Various statistics (e.g. regex hit percentage, transfer percentage).
-	stats
-	// Path of log file to tail.
-	filePath string
-	// Only consider all log lines matching this regular expression.
-	re *regexp.Regexp
-	// The glob identifier of the file.
-	globID string
-	// Channel to send a server message to the dtail client
-	serverMessages chan<- string
-	// Signals to stop tailing the log file.
-	stop chan struct{}
-	// Periodically retry reading file.
-	retry bool
-	// Can I skip messages when there are too many?
-	canSkipLines bool
-	// Seek to the EOF before processing file?
-	seekEOF bool
-	// Mutex to control the stopping of the file
-	mutex   *sync.Mutex
-	limiter chan struct{}
-}
-
-// FilePath returns the full file path.
-func (f readFile) FilePath() string {
-	return f.filePath
-}
-
-// Retry reading the file on error?
-func (f readFile) Retry() bool {
-	return f.retry
-}
-
-// Start tailing a log file.
-func (f readFile) Start(lines chan<- LineRead, regex string) error {
-	defer func() {
-		select {
-		case <-f.limiter:
-		default:
-		}
-	}()
-
-	select {
-	case f.limiter <- struct{}{}:
-	default:
-		select {
-		case f.serverMessages <- logger.Warn(f.filePath, f.globID, "Server limit reached. Queuing file..."):
-		case <-f.stop:
-			return nil
-		}
-		f.limiter <- struct{}{}
-	}
-
-	fd, err := os.Open(f.filePath)
-	if err != nil {
-		return err
-	}
-	defer fd.Close()
-
-	if f.seekEOF {
-		fd.Seek(0, io.SeekEnd)
-	}
-
-	rawLines := make(chan []byte, 100)
-	truncate := make(chan struct{})
-
-	var wg sync.WaitGroup
-	wg.Add(1)
-
-	go f.periodicTruncateCheck(truncate)
-	go f.filter(&wg, rawLines, lines, regex)
-
-	err = f.read(fd, rawLines, truncate)
-	close(rawLines)
-	wg.Wait()
-
-	return err
-}
-
-func (f readFile) periodicTruncateCheck(truncate chan struct{}) {
-	for {
-		select {
-		case <-time.After(time.Second * 3):
-			select {
-			case truncate <- struct{}{}:
-			case <-f.stop:
-			}
-		case <-f.stop:
-			return
-		}
-	}
-}
-
-// Stop reading file.
-func (f readFile) Stop() {
-	f.mutex.Lock()
-	defer f.mutex.Unlock()
-
-	select {
-	case <-f.stop:
-		return
-	default:
-	}
-
-	close(f.stop)
-}
-
-func (f readFile) makeReader(fd *os.File) (reader *bufio.Reader, err error) {
-	switch {
-	case strings.HasSuffix(f.FilePath(), ".gz"):
-		fallthrough
-	case strings.HasSuffix(f.FilePath(), ".gzip"):
-		logger.Info(f.FilePath(), "Detected gzip compression format")
-		var gzipReader *gzip.Reader
-		gzipReader, err = gzip.NewReader(fd)
-		if err != nil {
-			return
-		}
-		reader = bufio.NewReader(gzipReader)
-	case strings.HasSuffix(f.FilePath(), ".zst"):
-		logger.Info(f.FilePath(), "Detected zstd compression format")
-		reader = bufio.NewReader(zstd.NewReader(fd))
-	default:
-		reader = bufio.NewReader(fd)
-	}
-
-	return
-}
-
-func (f readFile) read(fd *os.File, rawLines chan []byte, truncate <-chan struct{}) error {
-	reader, err := f.makeReader(fd)
-	if err != nil {
-		return err
-	}
-	rawLine := make([]byte, 0, 512)
-	var offset uint64
-
-	lineLengthThreshold := 1024 * 1024 // 1mb
-	longLineWarning := false
-
-	for {
-		select {
-		case <-truncate:
-			if isTruncated, err := f.truncated(fd); isTruncated {
-				return err
-			}
-			logger.Info(f.filePath, "Current offset", offset)
-
-		case <-f.stop:
-			return nil
-		default:
-		}
-
-		// Read some bytes (max 4k at once as of go 1.12). isPrefix will
-		// be set if line does not fit into 4k buffer.
-		bytes, isPrefix, err := reader.ReadLine()
-
-		if err != nil {
-			// If EOF, sleep a couple of ms and return with nil error.
-			// If other error, return with non-nil error.
-			if err != io.EOF {
-				return err
-			}
-			if !f.seekEOF {
-				logger.Debug(f.FilePath(), "End of file reached")
-				return nil
-			}
-			time.Sleep(time.Millisecond * 100)
-			continue
-		}
-
-		rawLine = append(rawLine, bytes...)
-		offset += uint64(len(bytes))
-
-		if !isPrefix {
-			// last LineRead call returned contend until end of line.
-			rawLine = append(rawLine, '\n')
-			select {
-			case rawLines <- rawLine:
-			case <-f.stop:
-				return nil
-			}
-			rawLine = make([]byte, 0, 512)
-			if longLineWarning {
-				longLineWarning = false
-			}
-			continue
-		}
-
-		// Last LineRead call could not read content until end of line, buffer
-		// was too small. Determine whether we exceed the max line length we
-		// want dtail to send to the client at once. Possibly split up log line
-		// into multiple log lines.
-		if len(rawLine) >= lineLengthThreshold {
-			if !longLineWarning {
-				f.serverMessages <- logger.Warn(f.filePath, "Long log line, splitting into multiple lines")
-				// Only print out one warning per long log line.
-				longLineWarning = true
-			}
-			rawLine = append(rawLine, '\n')
-			select {
-			case rawLines <- rawLine:
-			case <-f.stop:
-				return nil
-			}
-			rawLine = make([]byte, 0, 512)
-		}
-	}
-}
-
-// Filter log lines matching a given regular expression.
-func (f readFile) filter(wg *sync.WaitGroup, rawLines <-chan []byte, lines chan<- LineRead, regex string) {
-	defer wg.Done()
-
-	if regex == "" {
-		regex = "."
-	}
-
-	re, err := regexp.Compile(regex)
-	if err != nil {
-		logger.Error(regex, "Can't compile regex, using '.' instead", err)
-		re = regexp.MustCompile(".")
-	}
-	f.re = re
-
-	for {
-		select {
-		case line, ok := <-rawLines:
-			f.updatePosition()
-			if !ok {
-				return
-			}
-			if filteredLine, ok := f.transmittable(line, len(lines), cap(lines)); ok {
-				select {
-				case lines <- filteredLine:
-				case <-f.stop:
-					return
-				}
-			}
-		}
-	}
-}
-
-func (f readFile) transmittable(line []byte, length, capacity int) (LineRead, bool) {
-	var read LineRead
-
-	if !f.re.Match(line) {
-		f.updateLineNotMatched()
-		f.updateLineNotTransmitted()
-		return read, false
-	}
-	f.updateLineMatched()
-
-	// Can we actually send more messages, channel capacity reached?
-	if f.canSkipLines && length >= capacity {
-		f.updateLineNotTransmitted()
-		return read, false
-	}
-	f.updateLineTransmitted()
-
-	read = LineRead{
-		Content:         line,
-		GlobID:          &f.globID,
-		Count:           f.totalLineCount(),
-		TransmittedPerc: f.transmittedPerc(),
-	}
-
-	return read, true
-}
-
-// Check wether log file is truncated. Returns nil if not.
-func (f readFile) truncated(fd *os.File) (bool, error) {
-	logger.Debug(f.filePath, "File truncation check")
-
-	// Can not seek currently open FD.
-	curPos, err := fd.Seek(0, os.SEEK_CUR)
-	if err != nil {
-		return true, err
-	}
-
-	// Can not open file at original path.
-	pathFd, err := os.Open(f.filePath)
-	if err != nil {
-		return true, err
-	}
-	defer pathFd.Close()
-
-	// Can not seek file at original path.
-	pathPos, err := pathFd.Seek(0, io.SeekEnd)
-	if err != nil {
-		return true, err
-	}
-
-	if curPos > pathPos {
-		return true, errors.New("File got truncated")
-	}
-
-	return false, nil
-}
diff --git a/internal/fs/stats.go b/internal/fs/stats.go
deleted file mode 100644
index 4121ff7..0000000
--- a/internal/fs/stats.go
+++ /dev/null
@@ -1,69 +0,0 @@
-package fs
-
-// Used to calculate how many log lines matched the regular expression
-// and how many log files could be transmitted from the server to the client.
-// Hit and transmit percentage takes only the last 100 log lines into calculation.
-type stats struct {
-	pos           int
-	lineCount     uint64
-	matched       [100]bool
-	matchCount    uint64
-	transmitted   [100]bool
-	transmitCount int
-}
-
-// Return the total line count.
-func (f *stats) totalLineCount() uint64 {
-	return f.lineCount
-}
-
-// Calculate the percentage of log lines transmitted to the client.
-func (f *stats) transmittedPerc() int {
-	return int(percentOf(float64(f.matchCount), float64(f.transmitCount)))
-}
-
-// Update bucket position. We only take into consideration the last 100
-// lines for stats.
-func (f *stats) updatePosition() {
-	f.pos = (f.pos + 1) % 100
-	f.lineCount++
-}
-
-// Increment match counter.
-func (f *stats) updateLineMatched() {
-	if !f.matched[f.pos] {
-		f.matchCount++
-		f.matched[f.pos] = true
-	}
-}
-
-// Increment transmitted counter.
-func (f *stats) updateLineTransmitted() {
-	if !f.transmitted[f.pos] {
-		f.transmitCount++
-		f.transmitted[f.pos] = true
-	}
-}
-
-// Decrement match counter.
-func (f *stats) updateLineNotMatched() {
-	if f.matched[f.pos] {
-		f.matchCount--
-		f.matched[f.pos] = false
-	}
-}
-
-// Decrement transmitted counter.
-func (f *stats) updateLineNotTransmitted() {
-	if f.transmitted[f.pos] {
-		f.transmitCount--
-		f.transmitted[f.pos] = false
-	}
-}
-
-func percentOf(total float64, value float64) float64 {
-	if total == 0 || total == value {
-		return 100
-	}
-	return value / (total / 100.0)
-}
diff --git a/internal/fs/tailfile.go b/internal/fs/tailfile.go
deleted file mode 100644
index a19d4e6..0000000
--- a/internal/fs/tailfile.go
+++ /dev/null
@@ -1,27 +0,0 @@
-package fs
-
-import "sync"
-
-// TailFile is to tail and filter a log file.
-type TailFile struct {
-	readFile
-}
-
-// NewTailFile returns a new file tailer.
-func NewTailFile(filePath string, globID string, serverMessages chan<- string, limiter chan struct{}) TailFile {
-	var mutex sync.Mutex
-
-	return TailFile{
-		readFile: readFile{
-			filePath:       filePath,
-			stop:           make(chan struct{}),
-			globID:         globID,
-			serverMessages: serverMessages,
-			retry:          true,
-			canSkipLines:   true,
-			seekEOF:        true,
-			limiter:        limiter,
-			mutex:          &mutex,
-		},
-	}
-}