Java
安裝 Jenkins 需要 Java8 或更高版本，但您執行的是 1.7.0
自2017 年以來，Jenkins 放棄了對 Java 7 的支持，現在開始使用 Java 8。
我正在嘗試在 Debian Jessie（docker 容器）上安裝 Jenkins，並且我正在使用通過此連結獲得的以下過程：
wget -q -O - https://pkg.jenkins.io/debian/jenkins.io.key | sudo apt-key add - sudo sh -c 'echo deb http://pkg.jenkins.io/debian-stable binary/ > /etc/apt/sources.list.d/jenkins.list' sudo apt-get update sudo apt-get install jenkins在程序的最後一步，發生了這樣的事情：
$ apt-get install jenkins Reading package lists... Done Building dependency tree Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation: The following packages have unmet dependencies: jenkins : Depends: default-jre-headless (>= 2:1.8) but 2:1.7-52 is to be installed or java8-runtime-headless but it is not installable E: Unable to correct problems, you have held broken packages.我在這裡找到了解決方案：
$ apt install -t jessie-backports openjdk-8-jre-headless ca-certificates-java無論如何，我設法安裝了 Jenkins，但是當啟動 Jenkins 時，會發生這種情況：
$ sudo /etc/init.d/jenkins start [FAIL] Starting Jenkins Automation Server: jenkins failed! $ tail -f /var/log/jenkins/jenkins.log Jenkins requires Java8 or later, but you are running 1.7.0_151-b01 from /usr/lib/jvm/java-7-openjdk-amd64/jre java.lang.UnsupportedClassVersionError: 51.0 at Main.main(Main.java:124)例如，我是否必須將 Java 8 安裝到 Debian Jessie？
我發現有導致衝突的 JRE 包。
前：
$ sudo dpkg -l | grep --color 'java\|jdk\|jre' ii ca-certificates-java 20161107~bpo8+1 all Common CA certificates (JKS keystore) ii default-jre-headless 2:1.7-52 amd64 Standard Java or Java compatible Runtime (headless) ii java-common 0.52 all Base of all Java packages ii libatk-wrapper-java 0.30.5-1 all ATK implementation for Java using JNI ii libatk-wrapper-java-jni:amd64 0.30.5-1 amd64 ATK implementation for Java using JNI (JNI bindings) ii openjdk-7-jre:amd64 7u151-2.6.11-2~deb8u1 amd64 OpenJDK Java runtime, using Hotspot JIT pi openjdk-7-jre-headless:amd64 7u151-2.6.11-2~deb8u1 amd64 OpenJDK Java runtime, using Hotspot JIT (headless) ii openjdk-8-jre-headless:amd64 8u131-b11-1~bpo8+1 amd64 OpenJDK Java runtime, using Hotspot JIT (headless) ii tzdata-java 2017c-0+deb8u1 all time zone and daylight-saving time data for use by java runtimes刪除包：
$ sudo dpkg -P openjdk-7-jre:amd64 (Reading database ... 15248 files and directories currently installed.) Removing openjdk-7-jre:amd64 (7u151-2.6.11-2~deb8u1) ... Processing triggers for hicolor-icon-theme (0.13-1) ... $ sudo dpkg -P openjdk-7-jre-headless:amd64 (Reading database ... 15222 files and directories currently installed.) Removing openjdk-7-jre-headless:amd64 (7u151-2.6.11-2~deb8u1) ... update-alternatives: using /usr/lib/jvm/java-8-openjdk-amd64/jre/bin/rmid to provide /usr/bin/rmid (rmid) in auto mode update-alternatives: using /usr/lib/jvm/java-8-openjdk-amd64/jre/bin/java to provide /usr/bin/java (java) in auto mode update-alternatives: using /usr/lib/jvm/java-8-openjdk-amd64/jre/bin/keytool to provide /usr/bin/keytool (keytool) in auto mode update-alternatives: using /usr/lib/jvm/java-8-openjdk-amd64/jre/bin/pack200 to provide /usr/bin/pack200 (pack200) in auto mode update-alternatives: using /usr/lib/jvm/java-8-openjdk-amd64/jre/bin/rmiregistry to provide /usr/bin/rmiregistry (rmiregistry) in auto mode update-alternatives: using /usr/lib/jvm/java-8-openjdk-amd64/jre/bin/unpack200 to provide /usr/bin/unpack200 (unpack200) in auto mode update-alternatives: using /usr/lib/jvm/java-8-openjdk-amd64/jre/bin/orbd to provide /usr/bin/orbd (orbd) in auto mode update-alternatives: using /usr/lib/jvm/java-8-openjdk-amd64/jre/bin/servertool to provide /usr/bin/servertool (servertool) in auto mode update-alternatives: using /usr/lib/jvm/java-8-openjdk-amd64/jre/bin/tnameserv to provide /usr/bin/tnameserv (tnameserv) in auto mode update-alternatives: using /usr/lib/jvm/java-8-openjdk-amd64/jre/lib/jexec to provide /usr/bin/jexec (jexec) in auto mode Purging configuration files for openjdk-7-jre-headless:amd64 (7u151-2.6.11-2~deb8u1) ...後：
$ dpkg -l | grep --color 'java\|jdk\|jre' ii ca-certificates-java 20161107~bpo8+1 all Common CA certificates (JKS keystore) ii java-common 0.52 all Base of all Java packages ii libatk-wrapper-java 0.30.5-1 all ATK implementation for Java using JNI ii libatk-wrapper-java-jni:amd64 0.30.5-1 amd64 ATK implementation for Java using JNI (JNI bindings) ii openjdk-8-jre-headless:amd64 8u131-b11-1~bpo8+1 amd64 OpenJDK Java runtime, using Hotspot JIT (headless) ii tzdata-java 2017c-0+deb8u1 all time zone and daylight-saving time data for use by java runtimes啟動詹金斯：
$ /etc/init.d/jenkins start [ ok ] Starting Jenkins Automation Server: jenkins. $ tail -f /var/log/jenkins/jenkins.log Jan 19, 2018 1:22:39 PM hudson.model.DownloadService$Downloadable load INFO: Obtained the updated data file for hudson.tasks.Maven.MavenInstaller Jan 19, 2018 1:22:41 PM hudson.model.DownloadService$Downloadable load INFO: Obtained the updated data file for hudson.tools.JDKInstaller Jan 19, 2018 1:22:41 PM hudson.model.AsyncPeriodicWork$1 run INFO: Finished Download metadata. 9,126 ms Jan 19, 2018 1:22:43 PM hudson.model.UpdateSite updateData INFO: Obtained the latest update center data file for UpdateSource default Jan 19, 2018 1:22:43 PM hudson.WebAppMain$3 run INFO: Jenkins is fully up and running加：
預設情況下，Jenkins 通過本地主機（埠 8080）。
**使用者：**管理員
密碼： cat /var/lib/jenkins/secrets/initialAdminPassword