Prometheus之Dockerfile编写、镜像构建、容器启动

2021-08-28 22:43:19

从官方镜像启动：prom/prometheus
官方Dockerfile分析
编写自己的Dockerfile
- 构建镜像：
- 启动容器：

从官方镜像启动：prom/prometheus

拉取镜像

$ docker pull prom/prometheus

启动容器

方式1：

$ docker run -td -p 9090:9090 --name prometheus1 prom/prometheus

方式2：路径挂载

$ docker run \

    -p 9090:9090 \

    -v /path/to/prometheus.yml:/etc/prometheus/prometheus.yml \

    prom/prometheus

$ docker run \

    -p 9090:9090 \

    -v /path/to/config:/etc/prometheus \

    prom/prometheus

官方Dockerfile分析

官方Dockerfile文件如下

ARG ARCH="amd64"

ARG OS="linux"

FROM quay.io/prometheus/busybox-${OS}-${ARCH}:latest

LABEL maintainer="The Prometheus Authors <prometheus-developers@googlegroups.com>"

ARG ARCH="amd64"

ARG OS="linux"

COPY .build/${OS}-${ARCH}/prometheus        /bin/prometheus

COPY .build/${OS}-${ARCH}/promtool          /bin/promtool

COPY documentation/examples/prometheus.yml  /etc/prometheus/prometheus.yml

COPY console_libraries/                     /usr/share/prometheus/console_libraries/

COPY consoles/                              /usr/share/prometheus/consoles/

COPY LICENSE                                /LICENSE

COPY NOTICE                                 /NOTICE

COPY npm_licenses.tar.bz2                   /npm_licenses.tar.bz2

WORKDIR /prometheus

RUN ln -s /usr/share/prometheus/console_libraries /usr/share/prometheus/consoles/ /etc/prometheus/ && \

    chown -R nobody:nobody /etc/prometheus /prometheus

USER       nobody

EXPOSE     9090

VOLUME     [ "/prometheus" ]

ENTRYPOINT [ "/bin/prometheus" ]

CMD        [ "--config.file=/etc/prometheus/prometheus.yml", \

             "--storage.tsdb.path=/prometheus", \

             "--web.console.libraries=/usr/share/prometheus/console_libraries", \

             "--web.console.templates=/usr/share/prometheus/consoles" ]

从官网Dockerfile文件可知：

使用busybox作为基础镜像
拷贝相关文件（prometheus、promtool、prometheus.yml等）到指定目录（/bin、/etc）
指定工作目录/prometheus
容器内端口9090
指定默认匿名卷为"/prometheus"，Prometheus运行产生的数据将写到宿主机相关目录
ENTRYPOINT容器启动入口点为"/bin/prometheus"
CMD指定容器启动参数为："--config.file=/etc/prometheus/prometheus.yml", "--storage.tsdb.path=/prometheus","--web.console.libraries=/usr/share/prometheus/console_libraries", "--web.console.templates=/usr/share/prometheus/consoles"

容器内Prometheus启动命令为：

/bin/prometheus --config.file=/etc/prometheus/prometheus.yml --storage.tsdb.path=/prometheus --web.console.libraries=/usr/share/prometheus/console_libraries --web.console.templates=/usr/share/prometheus/consoles

进入容器查看Prometheus的进程：

[root@docker ~]# docker exec -it prometheus1 sh

/prometheus $

/prometheus $ ps -ef | grep prometheu[s]

    1 nobody    0:53 /bin/prometheus --config.file=/etc/prometheus/prometheus.yml --storage.tsdb.path=/prometheus --web.console.libraries=/usr/share/prometheus/console_libraries --web.console.templates=/usr/share/prometheus/consoles

编写自己的Dockerfile

这里编写自己的Dockerfile进行构建，开启Prometheus进程的配置热加载和数据库管理功能。

FROM amd64/busybox:1.35

LABEL maintainer="The Prometheus Authors <wuenwuen>"

ARG ARCH="amd64"

ARG OS="linux"

COPY prometheus-*.${OS}-${ARCH}/prometheus 				/prometheus/bin/

COPY prometheus-*.${OS}-${ARCH}/promtool 				/prometheus/bin/

COPY prometheus-*.${OS}-${ARCH}/prometheus.yml 			/prometheus/etc/prometheus.yml

COPY prometheus-*.${OS}-${ARCH}/console_libraries/*    /prometheus/console_libraries/

COPY prometheus-*.${OS}-${ARCH}/consoles/*             /prometheus/consoles/

COPY prometheus-*.${OS}-${ARCH}/LICENSE               /prometheus/LICENSE

COPY prometheus-*.${OS}-${ARCH}/NOTICE                /prometheus/NOTICE

WORKDIR /prometheus

RUN ln -s /prometheus/bin/prometheus /prometheus/bin/promtool /bin/ && \

    chown -R root:root /prometheus

USER       root

EXPOSE     9090

VOLUME     [ "/prometheus/data", "/prometheus/etc" ]

ENTRYPOINT [ "/bin/prometheus" ]

CMD        [ "--config.file=/prometheus/etc/prometheus.yml", \

             "--storage.tsdb.path=/prometheus/data", \

             "--web.console.libraries=/prometheus/console_libraries", \

             "--web.console.templates=/prometheus/consoles", \

             "--web.enable-lifecycle", \

             "--web.enable-admin-api" ]

解读：

使用amd64/busybox:1.35作为基础镜像，将Prometheus的二进制文件放入bin目录，将配置文件统一放入etc目录；
将配置文件目录和数据存储目录定义为匿名卷；
启动方式中，新增两项配置，开启配置文件的热加载和数据库管理功能。

在同目录下添加一个.dockerignore文件，来屏蔽一些无关构建的文件：

prometheus-*.linux-amd64.tar.gz

etc

构建镜像：

新建目录，将版本包和Dockerfile文件放入该目录

# mkdir /root/prometheus;cd /root/prometheus

# ls

Dockerfile prometheus-2.33.1.linux-amd64.tar.gz

解压版本包，同时新建.dockerignore文件，在该文件下添加与构建无关的文件或目录（这表示构建时，不将这些文件复制到构建上下文环境中）

# tar -zxf prometheus-2.33.1.linux-amd64.tar.gz

# cat .dockerignore

prometheus-*.linux-amd64.tar.gz

执行构建命令docker build

$ docker build -t prometheus:v1 .

Sending build context to Docker daemon  200.8MB

Step 1/18 : FROM amd64/busybox:1.35

 ---> 96b2896db672

Step 2/18 : LABEL maintainer="The Prometheus Authors <wuenwuen>"

 ---> Running in 04e215d3c3e0

Removing intermediate container 04e215d3c3e0

 ---> 88050ed9e09d

Step 3/18 : ARG ARCH="amd64"

 ---> Running in 5ce5d1b12e0f

Removing intermediate container 5ce5d1b12e0f

 ---> 370832a62c71

Step 4/18 : ARG OS="linux"

 ---> Running in d7ea847b2d90

Removing intermediate container d7ea847b2d90

 ---> cf9781cb7722

Step 5/18 : COPY prometheus-*.${OS}-${ARCH}/prometheus                          /prometheus/bin/

 ---> 42b4b03f8332

Step 6/18 : COPY prometheus-*.${OS}-${ARCH}/promtool                            /prometheus/bin/

 ---> 897066bd0ca3

Step 7/18 : COPY prometheus-*.${OS}-${ARCH}/prometheus.yml                      /prometheus/etc/prometheus.yml

 ---> b141fa2c22a6

Step 8/18 : COPY prometheus-*.${OS}-${ARCH}/console_libraries/*    /prometheus/console_libraries/

 ---> 228b62d5e860

Step 9/18 : COPY prometheus-*.${OS}-${ARCH}/consoles/*             /prometheus/consoles/

 ---> 5c9125f39322

Step 10/18 : COPY prometheus-*.${OS}-${ARCH}/LICENSE                /prometheus/LICENSE

 ---> c89f57bbceb6

Step 11/18 : COPY prometheus-*.${OS}-${ARCH}/NOTICE                 /prometheus/NOTICE

 ---> 7e459dfd86fe

Step 12/18 : WORKDIR /prometheus

 ---> Running in 8f09cea3e03e

Removing intermediate container 8f09cea3e03e

 ---> ee1f386d159b

Step 13/18 : RUN ln -s /prometheus/bin/prometheus /prometheus/bin/promtool /bin/ &&     chown -R root:root /prometheus

 ---> Running in 093e9b6b8d14

Removing intermediate container 093e9b6b8d14

 ---> 121df7a93221

Step 14/18 : USER       root

 ---> Running in b4ffed0d491a

Removing intermediate container b4ffed0d491a

 ---> 75e2aada4653

Step 15/18 : EXPOSE     9090

 ---> Running in b09e22947d56

Removing intermediate container b09e22947d56

 ---> c700606bd44d

Step 16/18 : VOLUME     [ "/prometheus/data", "/prometheus/etc" ]

 ---> Running in e18dd4f3af2a

Removing intermediate container e18dd4f3af2a

 ---> 824d398febdd

Step 17/18 : ENTRYPOINT [ "/bin/prometheus" ]

 ---> Running in ff8fb122f2fb

Removing intermediate container ff8fb122f2fb

 ---> 414d2523bb9b

Step 18/18 : CMD        [ "--config.file=/prometheus/etc/prometheus.yml",              "--storage.tsdb.path=/prometheus/data",              "--web.console.libraries=/prometheus/console_libraries",              "--web.console.templates=/prometheus/consoles",              "--web.enable-lifecycle",              "--web.enable-admin-api" ]

 ---> Running in 56a8542d31a9

Removing intermediate container 56a8542d31a9

 ---> 17f5fa014281

Successfully built 17f5fa014281

Successfully tagged prometheus:v1

查看构建的镜像：

$ docker images

REPOSITORY        TAG       IMAGE ID       CREATED         SIZE

prometheus        v1        17f5fa014281   6 minutes ago   403MB

amd64/busybox     1.35      96b2896db672   2 weeks ago     1.24MB

prom/prometheus   latest    a3d385fc29f9   2 months ago    201MB

# 可以看到自己构建的镜像比官方镜像大了一倍

启动容器：

直接启动：

$ docker run -td prometheus:v1

$ docker run -td -p 9090:9090 prometheus:v1

直接启动后，配置文件和数据存储目录将默认使用匿名挂载。

挂载路径使用docker inspect命令查看

路径挂载（推荐）：

选择挂载出配置文件目录，数据存储目录使用默认的匿名挂载就行了。

由于路径挂载时，容器内挂载路径下的文件会被隐藏，同时Prometheus的启动又需要指定配置文件，所以启动容器前，需要提前将配置文件放在挂载点路径下，以避免容器启动后Prometheus进程无法启动，导致容器退出。

新建挂载点，并存放配置文件：

$ tree /root/prometheus/etc

/root/prometheus/etc

├── first_rules.yml

├── prometheus.yml

└── static_config

    └── node_exporter.yml

然后就可以使用构建的镜像来启动容器了，命令如下

# 选择其中一个即可

$ docker -td -v /root/prometheus/etc:/prometheus/etc prometheus:v1

$ docker run -td -p 9090:9090 --name prometheus-1 -v /root/prometheus/etc:/prometheus/etc prometheus:v1

$ docker run  \

	-td -p 9090:9090 --name prometheus-1 \

    -v /root/prometheus/etc:/prometheus/etc \

    prometheus:v1

查看容器：

$ docker ps

CONTAINER ID   IMAGE           COMMAND                  CREATED              STATUS              PORTS                                       NAMES

b2ebd62251ac   prometheus:v1   "/bin/prometheus --c…"   About a minute ago   Up About a minute   0.0.0.0:9090->9090/tcp, :::9090->9090/tcp   prometheus-1

$ docker ps --format "table {{.Image}}\t{{.ID}}\t{{.Ports}}\t{{.Status}}\t{{.Names}}"

IMAGE           CONTAINER ID   PORTS                                       STATUS         NAMES

prometheus:v1   b2ebd62251ac   0.0.0.0:9090->9090/tcp, :::9090->9090/tcp   Up 6 minutes   prometheus-1

访问Prometheus的UI界面：http://192.168.175.130:9090/

码农公寓

从官方镜像启动：prom/prometheus

官方Dockerfile分析

编写自己的Dockerfile

构建镜像：

启动容器：

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