构建最小 tomcat docker 镜像

# docker run -it --name debian debian:9 bin/bash

root@45104fade344:/# ldd bin/bash
  linux-vdso.so.1 (0x00007ffda05b1000) # 这一行无需理会
  libtinfo.so.5 => lib/x86_64-linux-gnu/libtinfo.so.5 (0x00007fdf4532f000)
  libdl.so.2 => lib/x86_64-linux-gnu/libdl.so.2 (0x00007fdf4512b000)
  libc.so.6 => lib/x86_64-linux-gnu/libc.so.6 (0x00007fdf44d8c000)
  lib64/ld-linux-x86-64.so.2 (0x0000564175f7f000)

mkdir -p tomcat_jdk8/{lib/x86_64-linux-gnu,bin,etc,usr/{lib/locale,local}}

docker cp debian:/bin/bash tomcat_jdk8/bin/
# -L 表示复制链接文件指向的实际文件
docker cp -L debian:/lib/x86_64-linux-gnu/libtinfo.so.5 tomcat_jdk8/lib/x86_64-linux-gnu/

# ls tomcat_jdk8/usr/local
jdk1.8.0_162

# cd tomcat_jdk8/usr/local/jdk1.8.0_162
# rm -rf *src.zip \
lib/missioncontrol \
lib/visualvm \
lib/*javafx* \
jre/lib/plugin.jar \
jre/lib/ext/jfxrt.jar \
jre/bin/javaws \
jre/lib/javaws.jar \
jre/lib/desktop \
jre/plugin \
jre/lib/deploy* \
jre/lib/*javafx* \
jre/lib/*jfx* \
jre/lib/amd64/libdecora_sse.so \
jre/lib/amd64/libprism_*.so \
jre/lib/amd64/libfxplugins.so \
jre/lib/amd64/libglass.so \
jre/lib/amd64/libgstreamer-lite.so \
jre/lib/amd64/libjavafx*.so \
jre/lib/amd64/libjfx*.so

# ln -s jdk1.8.0_162 java

# ls tomcat_jdk8/usr/local/
apache-tomcat-8.5.50  java  jdk1.8.0_162

---
startDelaySeconds: 0
ssl: false
lowercaseOutputName: false
lowercaseOutputLabelNames: false
whitelistObjectNames: ["org.apache.cassandra.metrics:*"]
blacklistObjectNames: ["org.apache.cassandra.metrics:type=ColumnFamily,*"]

ls tomcat_jdk8/usr/local/
apache-tomcat-8.5.50  config.yml  java  jdk1.8.0_162  jmx_prometheus_javaagent-0.12.0.jar  tomcat

/usr/local/java/bin/java -Djava.util.logging.config.file=/usr/local/tomcat/conf/logging.properties -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager -Djdk.tls.ephemeralDHKeySize=2048 -Djava.endorsed.dirs=/usr/local/tomcat/endorsed -classpath usr/local/tomcat/bin/bootstrap.jar:/usr/local/tomcat/bin/tomcat-juli.jar -Dcatalina.base=/usr/local/tomcat -Dcatalina.home=/usr/local/tomcat -Djava.io.tmpdir=/usr/local/tomcat/temp org.apache.catalina.startup.Bootstrap start

-server -Xmx128M -Xms128M

#!/bin/bash


# 先进行单位转换，然后计算出堆中各个区域的内存，会将容器的 requests 都作为堆内存
# 因为堆内存默认占据整个 jvm 的 80%（老外说的，未具体验证），所以 jvm 除了堆之外
# 还会占用额外 20% 的内存。所以注意 limits 的值一定要比 requests 大
# 至于大多少不好说，因为应用有可能除了使用 jvm 之外，还会使用系统内存作为缓存
# 所以容器的内存限制还要看具体的应用，最好先跑段时间，通过监控查看内存使用情况
# 不要认为 shell 的算术运算不支持浮点数就丢失精度
# 其实就算丢失精度也没啥，因为堆内存比容器最大内存小是应该的
# 如果比容器最大内存更大反而会出问题


unitConv() {
    value=$1
    unit=("" "K" "M" "G")
    idx=0
    while (($value > 10240)); do
        ((value/=1024))
        ((++idx))
    done
    echo "$value${unit[idx]}"
}


if [ -z "$JVM_HEAP" ]; then
    
    if [ -z "$MEM_TOTAL" ]; then
        echo "必须指定 JVM_HEAP|MEM_TOTAL 二者之一作为环境变量，且 MEM_TOTAL 必须以字节为单位"
        exit 1
    else
        heap=$(unitConv $MEM_TOTAL)
        young=$(unitConv $((MEM_TOTAL/2)))
        # PermSize 和 MaxPermSize 从 java8 中被移除
        JVM_HEAP=`echo -Xmx$heap -Xms$heap -Xmn$young`
    fi
fi


/usr/local/java/bin/java -Djava.util.logging.config.file=/usr/local/tomcat/conf/logging.properties -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager -server $JVM_HEAP -XX:SurvivorRatio=10 -XX:MaxTenuringThreshold=3 -XX:TargetSurvivorRatio=50 -XX:+UseParNewGC -XX:+UseConcMarkSweepGC -XX:CMSInitiatingOccupancyFraction=75 -XX:+CMSClassUnloadingEnabled -XX:+UseCMSInitiatingOccupancyOnly -XX:ParallelGCThreads=1 -XX:ConcGCThreads=1 -XX:+CMSParallelRemarkEnabled -XX:+CMSScavengeBeforeRemark -XX:+ExplicitGCInvokesConcurrent -XX:+UseTLAB -XX:TLABSize=2048K -Dsun.rmi.dgc.client.gcInterval=2592000000 -Dsun.rmi.dgc.server.gcInterval=2592000000 -Djava.awt.headless=true -Xloggc:/usr/local/tomcat/logs/gc.log -XX:+PrintGCDetails -XX:+PrintGCDateStamps -Djdk.tls.ephemeralDHKeySize=2048 -Djava.awt.headless=true -javaagent:/usr/local/jmx_prometheus_javaagent-0.12.0.jar=12356:/usr/local/config.yml -Djava.endorsed.dirs=/usr/local/tomcat/endorsed -classpath usr/local/tomcat/bin/bootstrap.jar:/usr/local/tomcat/bin/tomcat-juli.jar -Dcatalina.base=/usr/local/tomcat -Dcatalina.home=/usr/local/tomcat -Djava.io.tmpdir=/usr/local/tomcat/temp org.apache.catalina.startup.Bootstrap start

./busybox ls etc/

ln -s busybox ls
./ls etc/

# docker run --rm -it -v tomcat_jdk8/bin:/opt debian:10 /bin/bash
root@e39f29c2648d:/# cd /opt/
root@e39f29c2648d:/opt# for i in $(./busybox --list);do ln -s busybox $i;done

# docker run --rm -it debian:10 /bin/bash
apt update
apt install -y locales
localedef -i en_US -c -f UTF-8 -A /usr/share/locale/locale.alias en_US.UTF-8

tomcat_jdk8/
├── bin
│   ├── bash
│   ├── beep -> busybox
│   ├── blkid -> busybox
│   ├── ...
├── etc
│   ├── localtime
├── lib
│   └── x86_64-linux-gnu
│       └── libtinfo.so.5
└── usr
    ├── lib
    │   └── locale
    │       └── locale-archive
    └── local
        ├── apache-tomcat-8.5.50
        │   ...
        ├── config.yml
        ├── java -> jdk1.8.0_162
        ├── jdk1.8.0_162
        │   ...
        ├── jmx_prometheus_javaagent-0.12.0.jar
        └── tomcat -> apache-tomcat-8.5.50/

docker run -it -v /root/tomcat_jdk8:/opt python:3.6

import tarfile, os
os.chdir("/opt")
tar = tarfile.open("/tmp/x.tar", "w")
for i in os.listdir("."):
  tar.add(i)


tar.close()

mkdir dockerfiles
cd dockerfiles

FROM maxadd/distroless_base-debian10
ADD x.tar .
ENV JAVA_HOME=/usr/local/java LANG="en_US.utf8" PATH="/bin:/usr/local/java/bin"
EXPOSE 8080/tcp 12356/tcp
CMD ["/usr/local/tomcat/start.sh"]

docker build -t tomcat:8-jdk8-distroless .

docker run --rm -it -e "MEM_TOTAL=1333222222" --cap-add=SYS_PTRACE -p 11111:12356 tomcat:8-jdk8-distroless

curl 127.0.0.1:11111/metrics

# cat >/etc/yum.repos.d/bazel.repo <<'EOF'
[vbatts-bazel]
name=Copr repo for bazel owned by vbatts
baseurl=https://copr-be.cloud.fedoraproject.org/results/vbatts/bazel/epel-7-$basearch/
type=rpm-md
skip_if_unavailable=True
gpgcheck=1
EOF


# yum install bazel

# mkdir bazel

# cd bazel
# vim WORKSPACE
load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")


# Download the rules_docker repository at release v0.14.1
http_archive(
    name = "io_bazel_rules_docker",
    sha256 = "dc97fccceacd4c6be14e800b2a00693d5e8d07f69ee187babfd04a80a9f8e250",
    strip_prefix = "rules_docker-0.14.1",
    urls = ["https://github.com/bazelbuild/rules_docker/releases/download/v0.14.1/rules_docker-v0.14.1.tar.gz"],
)


# OPTIONAL: Call this to override the default docker toolchain configuration.
# This call should be placed BEFORE the call to "container_repositories" below
# to actually override the default toolchain configuration.
# Note this is only required if you actually want to call
# docker_toolchain_configure with a custom attr; please read the toolchains
# docs in /toolchains/docker/ before blindly adding this to your WORKSPACE.
# BEGIN OPTIONAL segment:
load("@io_bazel_rules_docker//toolchains/docker:toolchain.bzl",
    docker_toolchain_configure="toolchain_configure"
)


load(
    "@io_bazel_rules_docker//repositories:repositories.bzl",
    container_repositories = "repositories",
)
container_repositories()


# This is NOT needed when going through the language lang_image
# "repositories" function(s).
load("@io_bazel_rules_docker//repositories:deps.bzl", container_deps = "deps")


container_deps()


load(
    "@io_bazel_rules_docker//container:container.bzl",
    "container_pull",
)


container_pull(
  name = "base",
  # 因为使用的是我上传到 dockerhub 上的 distroless 镜像，因此 registry 需要指定为下面的值
  registry = "registry-1.docker.io",
  repository = "maxadd/distroless_base-debian10",
)

# touch BUILD
# mkdir tomcat
# cp /tmp/x.tar . # 将 tar 包复制到当前目录
# vim BUILD
load(
    "@io_bazel_rules_docker//container:container.bzl",
    "container_image",
)


container_image(
    name = "app",
    base = "@base//image",
    tars = ["x.tar"],
    env = {
        "PATH": "/bin:/usr/local/java/bin:/usr/local/java/jre/bin",
        "JAVA_HOME": "/usr/local/java",
        "LANG": "en_US.utf8"
    },
    workdir = "/usr/local/tomcat/webapps",
    ports = ["8080", "12356"],
    cmd = ["/usr/local/tomcat/start.sh"]
)

# cd ..
# bazel build //tomcat:app

bazel-bin/tomcat/app.executable

docker run --rm -it -e "MEM_TOTAL=1333222222" --cap-add=SYS_PTRACE -p 11111:12356 bazel/test:app