fix(log): output as many lines as possible if n > file lines

closes #221
- swap out slice-file dependency for `tail` and `read-last-lines`
- make `ghost log` instance-aware

Author: acburdine

lib/commands/log.js

@@ -1,14 +1,20 @@
 'use strict';
 const path = require('path');
 const includes = require('lodash/includes');
-const sliceFile = require('slice-file');
+const lastLines = require('read-last-lines');
+const Tail = require('tail').Tail;
+const Promise = require('bluebird');
 const PrettyStream = require('ghost-ignition/lib/logging/PrettyStream');
 
 const errors = require('../errors');
 const Command = require('../command');
 
 class LogCommand extends Command {
     run(argv) {
+        if (!argv.name) {
+            Command.checkValidInstall('log');
+        }
+
         let instance = this.system.getInstance(argv.name);
 
         if (!instance) {
@@ -34,7 +40,6 @@ class LogCommand extends Command {
         }
 
         let logFileName = path.join(process.cwd(), 'content/logs', `${instance.config.get('url').replace(/[^\w]/gi, '_')}_${this.system.environment}.log`);
-        let slice = sliceFile(logFileName);
         let prettyStream = new PrettyStream();
 
         prettyStream.on('error', (error) => {
@@ -45,17 +50,19 @@ class LogCommand extends Command {
 
         prettyStream.pipe(this.ui.stdout);
 
-        if (argv.follow) {
-            slice.follow(-argv.number).pipe(prettyStream);
-            return;
-        } else {
-            slice.slice(-argv.number).pipe(prettyStream);
-        }
+        return lastLines.read(logFileName, argv.number).then((lines) => {
+            lines.trim().split('\n').forEach(line => prettyStream.write(line));
+
+            if (argv.follow) {
+                let tail = new Tail(logFileName);
+                tail.on('line', (line) => prettyStream.write(line, 'utf8'));
+            }
+        });
     }
 }
 
 LogCommand.description = 'View logs of a running Ghost process';
-LogCommand.params = '<name>';
+LogCommand.params = '[name]';
 LogCommand.options = {
     number: {
         alias: 'n',

package.json

@@ -60,12 +60,13 @@
     "nginx-conf": "1.3.0",
     "ora": "1.3.0",
     "portfinder": "1.0.13",
+    "read-last-lines": "1.2.0",
     "rxjs": "5.4.1",
     "semver": "5.3.0",
     "shasum": "1.0.2",
-    "slice-file": "1.0.0",
     "strip-ansi": "4.0.0",
     "symlink-or-copy": "1.1.8",
+    "tail": "1.2.2",
     "update-notifier": "2.2.0",
     "validator": "7.2.0",
     "yargs": "8.0.2",

yarn.lock

@@ -80,6 +80,10 @@ ansi-styles@^2.2.1:
   version "2.2.1"
   resolved "https://registry.yarnpkg.com/ansi-styles/-/ansi-styles-2.2.1.tgz#b432dd3358b634cf75e1e4664368240533c1ddbe"
 
+any-promise@^1.0.0:
+  version "1.3.0"
+  resolved "https://registry.yarnpkg.com/any-promise/-/any-promise-1.3.0.tgz#abc6afeedcea52e809cdc0376aed3ce39635d17f"
+
 aproba@^1.0.3:
   version "1.1.2"
   resolved "https://registry.yarnpkg.com/aproba/-/aproba-1.1.2.tgz#45c6629094de4e96f693ef7eab74ae079c240fc1"
@@ -1219,6 +1223,25 @@ [email protected]:
     jsonfile "^3.0.0"
     universalify "^0.1.0"
 
+fs-extra@^0.26.5:
+  version "0.26.7"
+  resolved "https://registry.yarnpkg.com/fs-extra/-/fs-extra-0.26.7.tgz#9ae1fdd94897798edab76d0918cf42d0c3184fa9"
+  dependencies:
+    graceful-fs "^4.1.2"
+    jsonfile "^2.1.0"
+    klaw "^1.0.0"
+    path-is-absolute "^1.0.0"
+    rimraf "^2.2.8"
+
+fs-promise@^0.5.0:
+  version "0.5.0"
+  resolved "https://registry.yarnpkg.com/fs-promise/-/fs-promise-0.5.0.tgz#4347d6bf624655a7061a4319213c393276ad3ef3"
+  dependencies:
+    any-promise "^1.0.0"
+    fs-extra "^0.26.5"
+    mz "^2.3.1"
+    thenify-all "^1.6.0"
+
 fs.realpath@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/fs.realpath/-/fs.realpath-1.0.0.tgz#1504ad2523158caa40db4a2787cb01411994ea4f"
@@ -1434,7 +1457,7 @@ got@^7.0.0:
     timed-out "^4.0.0"
     url-parse-lax "^1.0.0"
 
-graceful-fs@^4.1.10, graceful-fs@^4.1.11, graceful-fs@^4.1.2, graceful-fs@^4.1.6:
+graceful-fs@^4.1.10, graceful-fs@^4.1.11, graceful-fs@^4.1.2, graceful-fs@^4.1.6, graceful-fs@^4.1.9:
   version "4.1.11"
   resolved "https://registry.yarnpkg.com/graceful-fs/-/graceful-fs-4.1.11.tgz#0e8bdfe4d1ddb8854d64e04ea7c00e2a026e5658"
 
@@ -1621,10 +1644,6 @@ inherits@2, inherits@^2.0.1, inherits@^2.0.3, inherits@~2.0.0, inherits@~2.0.1,
   version "2.0.3"
   resolved "https://registry.yarnpkg.com/inherits/-/inherits-2.0.3.tgz#633c2c83e3da42a502f52466022480f4208261de"
 
-inherits@~1.0.0:
-  version "1.0.2"
-  resolved "https://registry.yarnpkg.com/inherits/-/inherits-1.0.2.tgz#ca4309dadee6b54cc0b8d247e8d7c7a0975bdc9b"
-
 ini@^1.3.0, ini@^1.3.4, ini@~1.3.0:
   version "1.3.4"
   resolved "https://registry.yarnpkg.com/ini/-/ini-1.3.4.tgz#0537cb79daf59b59a1a517dff706c86ec039162e"
@@ -1935,6 +1954,12 @@ [email protected]:
   version "3.3.2"
   resolved "https://registry.yarnpkg.com/json3/-/json3-3.3.2.tgz#3c0434743df93e2f5c42aee7b19bcb483575f4e1"
 
+jsonfile@^2.1.0:
+  version "2.4.0"
+  resolved "https://registry.yarnpkg.com/jsonfile/-/jsonfile-2.4.0.tgz#3736a2b428b87bbda0cc83b53fa3d633a35c2ae8"
+  optionalDependencies:
+    graceful-fs "^4.1.6"
+
 jsonfile@^3.0.0:
   version "3.0.0"
   resolved "https://registry.yarnpkg.com/jsonfile/-/jsonfile-3.0.0.tgz#92e7c7444e5ffd5fa32e6a9ae8b85034df8347d0"
@@ -1970,6 +1995,12 @@ kind-of@^4.0.0:
   dependencies:
     is-buffer "^1.1.5"
 
+klaw@^1.0.0:
+  version "1.3.1"
+  resolved "https://registry.yarnpkg.com/klaw/-/klaw-1.3.1.tgz#4088433b46b3b1ba259d78785d8e96f73ba02439"
+  optionalDependencies:
+    graceful-fs "^4.1.9"
+
 [email protected]:
   version "2.0.16"
   resolved "https://registry.yarnpkg.com/knex-migrator/-/knex-migrator-2.0.16.tgz#6ac051d4e0fb2a8b633f8aab8b4d0019ecd4dd65"
@@ -2426,6 +2457,14 @@ mysql@^2.11.1:
     readable-stream "1.1.14"
     sqlstring "2.2.0"
 
+mz@^2.3.1:
+  version "2.6.0"
+  resolved "https://registry.yarnpkg.com/mz/-/mz-2.6.0.tgz#c8b8521d958df0a4f2768025db69c719ee4ef1ce"
+  dependencies:
+    any-promise "^1.0.0"
+    object-assign "^4.0.1"
+    thenify-all "^1.0.0"
+
 nan@^2.3.3, nan@~2.4.0:
   version "2.4.0"
   resolved "https://registry.yarnpkg.com/nan/-/nan-2.4.0.tgz#fb3c59d45fe4effe215f0b890f8adf6eb32d2232"
@@ -2904,6 +2943,12 @@ rc@^1.0.1, rc@^1.1.2, rc@^1.1.6, rc@^1.1.7:
     minimist "^1.2.0"
     strip-json-comments "~2.0.1"
 
+[email protected]:
+  version "1.2.0"
+  resolved "https://registry.yarnpkg.com/read-last-lines/-/read-last-lines-1.2.0.tgz#6970f68a2d5d03e1530b4b39373c00b941104890"
+  dependencies:
+    fs-promise "^0.5.0"
+
 read-pkg-up@^2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/read-pkg-up/-/read-pkg-up-2.0.0.tgz#6b72a8048984e0c41e79510fd5e9fa99b3b549be"
@@ -2934,15 +2979,6 @@ [email protected], readable-stream@^1.1.12:
     isarray "0.0.1"
     string_decoder "~0.10.x"
 
-"readable-stream@>=1.0.33-1 <1.1.0-0":
-  version "1.0.34"
-  resolved "https://registry.yarnpkg.com/readable-stream/-/readable-stream-1.0.34.tgz#125820e34bc842d2f2aaafafe4c2916ee32c157c"
-  dependencies:
-    core-util-is "~1.0.0"
-    inherits "~2.0.1"
-    isarray "0.0.1"
-    string_decoder "~0.10.x"
-
 readable-stream@^2.0.0, readable-stream@^2.0.5, readable-stream@^2.0.6, readable-stream@^2.1.4, readable-stream@^2.1.5, readable-stream@^2.2.2:
   version "2.3.1"
   resolved "https://registry.yarnpkg.com/readable-stream/-/readable-stream-2.3.1.tgz#84e26965bb9e785535ed256e8d38e92c69f09d10"
@@ -3291,14 +3327,6 @@ [email protected]:
   version "0.0.4"
   resolved "https://registry.yarnpkg.com/slice-ansi/-/slice-ansi-0.0.4.tgz#edbf8903f66f7ce2f8eafd6ceed65e264c831b35"
 
-[email protected]:
-  version "1.0.0"
-  resolved "https://registry.yarnpkg.com/slice-file/-/slice-file-1.0.0.tgz#8b6c79d0a50c3fc3c1159957478426443a9000b8"
-  dependencies:
-    inherits "~1.0.0"
-    split2 "^0.2.1"
-    through2 "^0.6.5"
-
 slide@^1.1.5:
   version "1.1.6"
   resolved "https://registry.yarnpkg.com/slide/-/slide-1.1.6.tgz#56eb027d65b4d2dce6cb2e2d32c4d4afc9e1d707"
@@ -3351,12 +3379,6 @@ spdx-license-ids@^1.0.2:
   version "1.2.2"
   resolved "https://registry.yarnpkg.com/spdx-license-ids/-/spdx-license-ids-1.2.2.tgz#c9df7a3424594ade6bd11900d596696dc06bac57"
 
-split2@^0.2.1:
-  version "0.2.1"
-  resolved "https://registry.yarnpkg.com/split2/-/split2-0.2.1.tgz#02ddac9adc03ec0bb78c1282ec079ca6e85ae900"
-  dependencies:
-    through2 "~0.6.1"
-
 sprintf-js@~1.0.2:
   version "1.0.3"
   resolved "https://registry.yarnpkg.com/sprintf-js/-/sprintf-js-1.0.3.tgz#04e6926f662895354f3dd015203633b857297e2c"
@@ -3492,6 +3514,10 @@ table@^4.0.1:
     slice-ansi "0.0.4"
     string-width "^2.0.0"
 
+[email protected]:
+  version "1.2.2"
+  resolved "https://registry.yarnpkg.com/tail/-/tail-1.2.2.tgz#3c40a47d53e137c541a14cc133532ecb2a75cc51"
+
 tar-fs@^1.15.1:
   version "1.15.3"
   resolved "https://registry.yarnpkg.com/tar-fs/-/tar-fs-1.15.3.tgz#eccf935e941493d8151028e636e51ce4c3ca7f20"
@@ -3552,12 +3578,17 @@ text-table@~0.2.0:
   version "0.2.0"
   resolved "https://registry.yarnpkg.com/text-table/-/text-table-0.2.0.tgz#7f5ee823ae805207c00af2df4a84ec3fcfa570b4"
 
-through2@^0.6.5, through2@~0.6.1:
-  version "0.6.5"
-  resolved "https://registry.yarnpkg.com/through2/-/through2-0.6.5.tgz#41ab9c67b29d57209071410e1d7a7a968cd3ad48"
+thenify-all@^1.0.0, thenify-all@^1.6.0:
+  version "1.6.0"
+  resolved "https://registry.yarnpkg.com/thenify-all/-/thenify-all-1.6.0.tgz#1a1918d402d8fc3f98fbf234db0bcc8cc10e9726"
+  dependencies:
+    thenify ">= 3.1.0 < 4"
+
+"thenify@>= 3.1.0 < 4":
+  version "3.3.0"
+  resolved "https://registry.yarnpkg.com/thenify/-/thenify-3.3.0.tgz#e69e38a1babe969b0108207978b9f62b88604839"
   dependencies:
-    readable-stream ">=1.0.33-1 <1.1.0-0"
-    xtend ">=4.0.0 <4.1.0-0"
+    any-promise "^1.0.0"
 
 through2@^2.0.3:
   version "2.0.3"
@@ -3820,7 +3851,7 @@ xdg-basedir@^3.0.0:
   version "3.0.0"
   resolved "https://registry.yarnpkg.com/xdg-basedir/-/xdg-basedir-3.0.0.tgz#496b2cc109eca8dbacfe2dc72b603c17c5870ad4"
 
-"xtend@>=4.0.0 <4.1.0-0", xtend@^4.0.0, xtend@~4.0.1:
+xtend@^4.0.0, xtend@~4.0.1:
   version "4.0.1"
   resolved "https://registry.yarnpkg.com/xtend/-/xtend-4.0.1.tgz#a5c6d532be656e23db820efb943a1f04998d63af"