docker如何查看容器的日志

在前面写的文章中，有一篇是一个蜜罐SSH服务器的例子，里面使用了docker logs -f 容器名或容器ID命令来查看容器的日志。这是Docker中查看容器日志的常用方法。

默认情况下，docker logs的输出一般会显示容器内应用程序执行结果的日志内容，也可以说是容器内应用程序执行命令的STDOUT和STDERR。

日志文件的存放位置为/var/lib/docker/containers/容器ID。

命令docker system df除了可以查看镜像的空间占用情况，也可以看日志的空间使用情况。

查看容器日志的命令格式如下：

docker logs [OPTIONS] CONTAINER

其中包含了以下的选项：

-f, --follow：跟踪日志输出。

--tail：从指定的条目开始输出日志（例如 --tail 10 显示最后10条日志）。

--since：显示自给定时间以来的日志（例如 --since 1h30m 显示最近1小时30分钟的日志）。

--until：显示直到给定时间为止的日志。

--details：显示日志的更多细节。

下面是几个查看容器日志的例子：

例一：查看一个memos的容器日志，因为命令没有添加任何选项，其会把日志的全部内容都打印出来：

[root@desktop-centos ~]# docker logs root-memos-1
---
Server profile
version: 0.22.1
data: /var/opt/memos
dsn: /var/opt/memos/memos_prod.db
addr:
port: 5230
mode: prod
driver: sqlite
---
succeed to copy a backup database file
start migrate
applying migration for 0.19.0
applying migration for 0.20.0
applying migration for 0.21.0
applying migration for 0.22.0
end migrate

███╗   ███╗███████╗███╗   ███╗ ██████╗ ███████╗
████╗ ████║██╔════╝████╗ ████║██╔═══██╗██╔════╝
██╔████╔██║█████╗  ██╔████╔██║██║   ██║███████╗
██║╚██╔╝██║██╔══╝  ██║╚██╔╝██║██║   ██║╚════██║
██║ ╚═╝ ██║███████╗██║ ╚═╝ ██║╚██████╔╝███████║
╚═╝     ╚═╝╚══════╝╚═╝     ╚═╝ ╚═════╝ ╚══════╝
Version 0.22.1 has been started on port 5230
---
See more in:
Website: https://usememos.com
GitHub: https://github.com/usememos/memos
 --- 略 ---

跟踪日志输出：

[root@desktop-centos ~]# docker logs -f root-memos-1
--- 略 ---
 2024/10/02 02:28:28 INFO OK method=/memos.api.v1.WorkspaceService/GetWorkspaceProfile
 2024/10/02 02:28:28 INFO client error method=/memos.api.v1.AuthService/GetAuthStatus error="rpc error: code = Unauthenticated desc = user not found"
 2024/10/02 02:28:28 INFO OK method=/memos.api.v1.WorkspaceSettingService/GetWorkspaceSetting
 2024/10/02 02:28:28 INFO OK method=/memos.api.v1.WorkspaceSettingService/GetWorkspaceSetting
 2024/10/02 02:28:28 INFO OK method=/memos.api.v1.WorkspaceService/GetWorkspaceProfile
 2024/10/02 02:28:28 INFO client error method=/memos.api.v1.AuthService/GetAuthStatus error="rpc error: code = Unauthenticated desc = user not found"
 2024/10/02 02:28:28 INFO OK method=/memos.api.v1.WorkspaceSettingService/GetWorkspaceSetting
 2024/10/02 02:28:28 INFO OK method=/memos.api.v1.WorkspaceSettingService/GetWorkspaceSetting
 2024/10/02 02:28:28 INFO OK method=/memos.api.v1.MemoService/ListMemos
 2024/10/02 02:28:29 INFO OK method=/memos.api.v1.UserService/GetUser
 2024/10/02 02:28:29 INFO OK method=/memos.api.v1.MemoService/ListMemoTags

查看最后10条日志：

[root@desktop-centos ~]# docker logs --tail 10 root-memos-1
2024/10/02 02:28:28 INFO client error method=/memos.api.v1.AuthService/GetAuthStatus error="rpc error: code = Unauthenticated desc = user not found"
2024/10/02 02:28:28 INFO OK method=/memos.api.v1.WorkspaceSettingService/GetWorkspaceSetting
2024/10/02 02:28:28 INFO OK method=/memos.api.v1.WorkspaceSettingService/GetWorkspaceSetting
2024/10/02 02:28:28 INFO OK method=/memos.api.v1.WorkspaceService/GetWorkspaceProfile
2024/10/02 02:28:28 INFO client error method=/memos.api.v1.AuthService/GetAuthStatus error="rpc error: code = Unauthenticated desc = user not found"
2024/10/02 02:28:28 INFO OK method=/memos.api.v1.WorkspaceSettingService/GetWorkspaceSetting
2024/10/02 02:28:28 INFO OK method=/memos.api.v1.WorkspaceSettingService/GetWorkspaceSetting
2024/10/02 02:28:28 INFO OK method=/memos.api.v1.MemoService/ListMemos
2024/10/02 02:28:29 INFO OK method=/memos.api.v1.UserService/GetUser
2024/10/02 02:28:29 INFO OK method=/memos.api.v1.MemoService/ListMemoTags

查看某个时间点之后的日志：

[root@desktop-centos ~]# docker logs --since "2024-10-02T02:00:00" root-memos-1
2024/10/02 02:28:28 INFO OK method=/memos.api.v1.WorkspaceService/GetWorkspaceProfile
2024/10/02 02:28:28 INFO client error method=/memos.api.v1.AuthService/GetAuthStatus error="rpc error: code = Unauthenticated desc = user not found"
2024/10/02 02:28:28 INFO OK method=/memos.api.v1.WorkspaceSettingService/GetWorkspaceSetting
2024/10/02 02:28:28 INFO OK method=/memos.api.v1.WorkspaceSettingService/GetWorkspaceSetting
2024/10/02 02:28:28 INFO OK method=/memos.api.v1.WorkspaceService/GetWorkspaceProfile
2024/10/02 02:28:28 INFO client error method=/memos.api.v1.AuthService/GetAuthStatus error="rpc error: code = Unauthenticated desc = user not found"
2024/10/02 02:28:28 INFO OK method=/memos.api.v1.WorkspaceSettingService/GetWorkspaceSetting
2024/10/02 02:28:28 INFO OK method=/memos.api.v1.WorkspaceSettingService/GetWorkspaceSetting
2024/10/02 02:28:28 INFO OK method=/memos.api.v1.MemoService/ListMemos
2024/10/02 02:28:29 INFO OK method=/memos.api.v1.UserService/GetUser
2024/10/02 02:28:29 INFO OK method=/memos.api.v1.MemoService/ListMemoTags

查看某个时间点之前的日志：

[root@desktop-centos ~]# docker logs --until "2024-10-02T02:00:00" root-memos-1
 --- 略 ---
2024/08/16 03:11:38 INFO OK method=/memos.api.v1.WorkspaceSettingService/GetWorkspaceSetting
2024/08/16 03:11:38 INFO OK method=/memos.api.v1.UserService/ListUserAccessTokens
2024/08/16 03:11:38 INFO OK method=/memos.api.v1.WorkspaceSettingService/GetWorkspaceSetting
2024/08/16 03:11:43 INFO OK method=/memos.api.v1.WebhookService/ListWebhooks
2024/08/16 03:11:44 INFO OK method=/memos.api.v1.MemoService/ListMemoProperties
2024/08/16 03:11:44 INFO OK method=/memos.api.v1.MemoService/ListMemoTags
2024/08/16 03:11:44 INFO OK method=/memos.api.v1.MemoService/ListMemos
2024/08/16 03:11:44 INFO OK method=/memos.api.v1.MemoService/ListMemoProperties
2024/08/16 03:11:44 INFO OK method=/memos.api.v1.MemoService/ListMemoTags
2024/08/16 03:11:50 INFO OK method=/memos.api.v1.ActivityService/GetActivity
2024/08/16 03:11:50 INFO OK method=/memos.api.v1.InboxService/ListInboxes
2024/08/16 03:11:50 INFO OK method=/memos.api.v1.ActivityService/GetActivity
2024/08/16 03:11:50 INFO OK method=/memos.api.v1.ActivityService/GetActivity
2024/08/16 03:11:53 INFO OK method=/memos.api.v1.InboxService/UpdateInbox
2024/08/16 03:11:53 INFO OK method=/memos.api.v1.ActivityService/GetActivity
2024/08/16 03:11:55 INFO OK method=/memos.api.v1.InboxService/UpdateInbox
2024/08/16 03:11:55 INFO OK method=/memos.api.v1.ActivityService/GetActivity
2024/08/16 03:11:57 INFO OK method=/memos.api.v1.MemoService/ListMemoTags
2024/08/16 03:11:57 INFO OK method=/memos.api.v1.MemoService/ListMemoProperties
2024/08/16 03:11:57 INFO OK method=/memos.api.v1.MemoService/ListMemoProperties
2024/08/16 03:11:57 INFO OK method=/memos.api.v1.MemoService/ListMemos
2024/08/16 03:11:57 INFO OK method=/memos.api.v1.MemoService/ListMemoProperties
2024/08/16 03:11:58 INFO OK method=/memos.api.v1.MemoService/ListMemoTags
2024/08/16 03:11:59 INFO OK method=/memos.api.v1.MemoService/ListMemoProperties
2024/08/16 03:11:59 INFO OK method=/memos.api.v1.MemoService/ListMemoProperties
2024/08/16 03:11:59 INFO OK method=/memos.api.v1.MemoService/ListMemos
2024/08/16 03:11:59 INFO OK method=/memos.api.v1.MemoService/GetUserMemosStats
2024/08/16 03:11:59 INFO OK method=/memos.api.v1.MemoService/GetUserMemosStats
2024/08/16 03:11:59 INFO OK method=/memos.api.v1.MemoService/ListMemoProperties
2024/08/16 03:11:59 INFO OK method=/memos.api.v1.MemoService/GetUserMemosStats
2024/08/16 03:11:59 INFO OK method=/memos.api.v1.MemoService/ListMemoTags
2024/08/16 03:12:01 INFO OK method=/memos.api.v1.MemoService/ListMemoTags
2024/08/16 03:12:01 INFO OK method=/memos.api.v1.MemoService/ListMemoProperties
2024/08/16 03:12:01 INFO OK method=/memos.api.v1.MemoService/ListMemoProperties
2024/08/16 03:12:01 INFO OK method=/memos.api.v1.MemoService/ListMemos
2024/08/16 03:12:01 INFO OK method=/memos.api.v1.MemoService/ListMemoProperties
2024/08/16 03:12:02 INFO OK method=/memos.api.v1.MemoService/ListMemoTags

查看包含更多细节的日志：

[root@desktop-centos ~]# docker logs --details root-memos-1
 --- 略 ---
 2024/10/02 02:28:28 INFO OK method=/memos.api.v1.WorkspaceService/GetWorkspaceProfile
 2024/10/02 02:28:28 INFO client error method=/memos.api.v1.AuthService/GetAuthStatus error="rpc error: code = Unauthenticated desc = user not found"
 2024/10/02 02:28:28 INFO OK method=/memos.api.v1.WorkspaceSettingService/GetWorkspaceSetting
 2024/10/02 02:28:28 INFO OK method=/memos.api.v1.WorkspaceSettingService/GetWorkspaceSetting
 2024/10/02 02:28:28 INFO OK method=/memos.api.v1.WorkspaceService/GetWorkspaceProfile
 2024/10/02 02:28:28 INFO client error method=/memos.api.v1.AuthService/GetAuthStatus error="rpc error: code = Unauthenticated desc = user not found"
 2024/10/02 02:28:28 INFO OK method=/memos.api.v1.WorkspaceSettingService/GetWorkspaceSetting
 2024/10/02 02:28:28 INFO OK method=/memos.api.v1.WorkspaceSettingService/GetWorkspaceSetting
 2024/10/02 02:28:28 INFO OK method=/memos.api.v1.MemoService/ListMemos
 2024/10/02 02:28:29 INFO OK method=/memos.api.v1.UserService/GetUser
 2024/10/02 02:28:29 INFO OK method=/memos.api.v1.MemoService/ListMemoTags

请将 container_name_or_id 替换为你想要查看日志的容器名称或ID。

此外，如果你使用的是Docker Compose，可以使用以下命令查看服务的日志：

docker-compose logs [OPTIONS] [SERVICE...]

Docker默认使用json-file日志驱动程序，其将容器内部日志缓存为JSON格式，不执行日志轮换，存储的日志文件可能因占用大量存储空间，导致磁盘空间耗尽。因此建议使用“local”日志驱动程序，该驱动程序默认执行日志轮换，并使用更高效的文件格式。

Docker全局日志控制为在/etc/docker/daemon.json 文件中添加log-dirver和log-opts参数。如：

{
  "log-driver":"json-file",
  "log-opts": {"max-size":"500m", "max-file":"3"}
}

max-size=500m，意味着一个容器日志大小上限是500M， max-file=3，意味着一个容器有三个日志，分别是id+.json、id+1.json、id+2.json