Elasticsearch（5）Kibana

简介

Kibana是一个开源的分析与可视化平台，专门用于和Elasticsearch一起使用的。你可以用kibana搜索、查看存放在Elasticsearch中的数据，并且可以通过图标、表格等直观地展示数据，达到数据分析与可视化的目的。
Elasticsearch、Logstash和Kibana这三个技术就是我们常说的ELK技术栈，可以说这三个技术的组合是大数据领域中一个很巧妙的设计。一种很典型的MVC思想，模型持久层，视图层和控制层。Logstash担任控制层的角色，负责搜集和过滤数据。Elasticsearch担任数据持久层的角色，负责储存数据。而我们这章的主题Kibana担任视图层角色，拥有各种维度的查询和分析，并使用图形化的界面展示存放在Elasticsearch中的数据。

安装与启动

下载安装包

官方下载地址：https://www.elastic.co/cn/downloads/kibana。

关于Kibana的版本

这里需要注意 Kibana 的版本需要和 Elasticsearch 的版本一致。这是官方支持的配置。

运行不同主版本号的 Kibana 和 Elasticsearch 是不支持的（例如 Kibana 5.x 和 Elasticsearch 2.x），若主版本号相同，运行 Kibana 子版本号比 Elasticsearch 子版本号新的版本也是不支持的（例如 Kibana 5.1 和 Elasticsearch 5.0）。

运行一个 Elasticsearch 子版本号大于 Kibana 的版本基本不会有问题，这种情况一般是便于先将 Elasticsearch 升级（例如 Kibana 5.0 和 Elasticsearch 5.1）。在这种配置下，Kibana 启动日志中会出现一个警告，所以一般只是使用于 Kibana 即将要升级到和 Elasticsearch 相同版本的场景。

官方现在页提供最新版本的Kibana下载，如果你需要安装老的版本，可以从下载页面“past releases”这个入口去下载。

在本文示例中，我下载的文件是kibana-6.8.0-linux-x86_64.tar.gz。

上传解压

将下载好的压缩包上传至服务器，并解压。

配置

因为Kibana是要搭配Elasticsearch一起使用，所以肯定一定的配置项。
Kibana的配置文件在kibana-6.8.0-linux-x86_64/config目录中，文件名为kibana.yml。我们使用vim编辑器打开后可以看到，该文件所有的配置都是注释掉的，说明所有的配置都是使用默认的。

默认的配置文件内容：

# Kibana is served by a back end server. This setting specifies the port to use.
#server.port: 5601

# Specifies the address to which the Kibana server will bind. IP addresses and host names are both valid values.
# The default is 'localhost', which usually means remote machines will not be able to connect.
# To allow connections from remote users, set this parameter to a non-loopback address.
#server.host: "localhost"

# Enables you to specify a path to mount Kibana at if you are running behind a proxy.
# Use the `server.rewriteBasePath` setting to tell Kibana if it should remove the basePath
# from requests it receives, and to prevent a deprecation warning at startup.
# This setting cannot end in a slash.
#server.basePath: ""

# Specifies whether Kibana should rewrite requests that are prefixed with
# `server.basePath` or require that they are rewritten by your reverse proxy.
# This setting was effectively always `false` before Kibana 6.3 and will
# default to `true` starting in Kibana 7.0.
#server.rewriteBasePath: false

# The maximum payload size in bytes for incoming server requests.
#server.maxPayloadBytes: 1048576

# The Kibana server's name.  This is used for display purposes.
#server.name: "your-hostname"

# The URLs of the Elasticsearch instances to use for all your queries.
#elasticsearch.hosts: ["http://localhost:9200"]

# When this setting's value is true Kibana uses the hostname specified in the server.host
# setting. When the value of this setting is false, Kibana uses the hostname of the host
# that connects to this Kibana instance.
#elasticsearch.preserveHost: true

# Kibana uses an index in Elasticsearch to store saved searches, visualizations and
# dashboards. Kibana creates a new index if the index doesn't already exist.
#kibana.index: ".kibana"

# The default application to load.
#kibana.defaultAppId: "home"

# If your Elasticsearch is protected with basic authentication, these settings provide
# the username and password that the Kibana server uses to perform maintenance on the Kibana
# index at startup. Your Kibana users still need to authenticate with Elasticsearch, which
# is proxied through the Kibana server.
#elasticsearch.username: "user"
#elasticsearch.password: "pass"

# Enables SSL and paths to the PEM-format SSL certificate and SSL key files, respectively.
# These settings enable SSL for outgoing requests from the Kibana server to the browser.
#server.ssl.enabled: false
#server.ssl.certificate: /path/to/your/server.crt
#server.ssl.key: /path/to/your/server.key

# Optional settings that provide the paths to the PEM-format SSL certificate and key files.
# These files validate that your Elasticsearch backend uses the same key files.
#elasticsearch.ssl.certificate: /path/to/your/client.crt
#elasticsearch.ssl.key: /path/to/your/client.key

# Optional setting that enables you to specify a path to the PEM file for the certificate
# authority for your Elasticsearch instance.
#elasticsearch.ssl.certificateAuthorities: [ "/path/to/your/CA.pem" ]

# To disregard the validity of SSL certificates, change this setting's value to 'none'.
#elasticsearch.ssl.verificationMode: full

# Time in milliseconds to wait for Elasticsearch to respond to pings. Defaults to the value of
# the elasticsearch.requestTimeout setting.
#elasticsearch.pingTimeout: 1500

# Time in milliseconds to wait for responses from the back end or Elasticsearch. This value
# must be a positive integer.
#elasticsearch.requestTimeout: 30000

# List of Kibana client-side headers to send to Elasticsearch. To send *no* client-side
# headers, set this value to [] (an empty list).
#elasticsearch.requestHeadersWhitelist: [ authorization ]

# Header names and values that are sent to Elasticsearch. Any custom headers cannot be overwritten
# by client-side headers, regardless of the elasticsearch.requestHeadersWhitelist configuration.
#elasticsearch.customHeaders: {}

# Time in milliseconds for Elasticsearch to wait for responses from shards. Set to 0 to disable.
#elasticsearch.shardTimeout: 30000

# Time in milliseconds to wait for Elasticsearch at Kibana startup before retrying.
#elasticsearch.startupTimeout: 5000

# Logs queries sent to Elasticsearch. Requires logging.verbose set to true.
#elasticsearch.logQueries: false

# Specifies the path where Kibana creates the process ID file.
#pid.file: /var/run/kibana.pid

# Enables you specify a file where Kibana stores log output.
#logging.dest: stdout

# Set the value of this setting to true to suppress all logging output.
#logging.silent: false

# Set the value of this setting to true to suppress all logging output other than error messages.
#logging.quiet: false

# Set the value of this setting to true to log all events, including system usage information
# and all requests.
#logging.verbose: false

# Set the interval in milliseconds to sample system and process performance
# metrics. Minimum is 100ms. Defaults to 5000.
#ops.interval: 5000

# Specifies locale to be used for all localizable strings, dates and number formats.
#i18n.locale: "en"

主要有如下几个配置项需要关注下：

1. server.port（服务端口）：默认是5601。
2. elasticsearch.hosts（elasticsearch的服务配置）：elasticsearch集群服务的ip和端口。
3. elasticsearch.username和elasticsearch.password（elasticsearch的用户名和密码）：默认是没有用户名和密码，如果elasticsearch是配置了用户名和密码的，那就需要配置这两行属性
4. server.host（允许远程访问的地址配置）：默认只能本机访问，如果我们需要把Kibana服务给远程主机访问，只需要在这个配置中填写远程的那台主机的ip地址，那如果我们希望所有的远程主机都能访问，那就配置成0.0.0.0。
5. i18n.locale（语言）：默认是英语，如果要改成中文，就改用zh-CN。

启动

在Kibana的安装目录下，执行./bin/kibana启动服务。如果要以守护线程启动，执行nohup ./bin/kibana &命令，日志将会输出到当前目录下的nohup.out这个文件里。

访问

在本地浏览器，通过ip和端口访问Kibana服务。