jenkins執(zhí)行shell讀不到環(huán)境變量問題

1、jenkins執(zhí)行shell讀不到環(huán)境變量問題從系列中，了解到j(luò)enkins執(zhí)行shell的原理。在使用enkins過程中，發(fā)現(xiàn)執(zhí)行shell讀取不到J/etc/profilel以及用戶下.bash_profilei殳置的環(huán)境變量。環(huán)境:RedHatEnterprise5.5根據(jù)jenkins-core項目Shell.java的buildCommandLine方法publicStringbuildCommandLine(FilePathscript)if(commandstartsWith("#!")/interpreteroverrideintend=commandind

2、exOf('n');if(end<0)end=commandlength();List<String>argsnewArrayList<String>();argsaddAll(ArraysasList(Utiltokenize(commandsubstring(0,end).trim();argsadd(scriptgetRemote();argsset(0,argsget(0).substring(2);/trimoff"#!"returnargstoArray(newStringargssize();elsereturnn

3、ewStringgetDescriptor().getShellOrDefault(scriptgetChannel(),"-xe",scriptgetRemote();在默認(rèn)的情況下，執(zhí)行shell會在節(jié)點上tmp目錄生成類似hudson224519953209659762.sh后面數(shù)字根據(jù)規(guī)則生成，具體執(zhí)行的命令如:/bin/sh-xe/tmp/hudson224519953209659762.s。如果ExecuteShell里面具體命令為以下內(nèi)容：#!/bin/bash+x那么根據(jù)上面代碼，具體執(zhí)行的命令就會變成/bin/bash+x/tmp/hudson224519

4、953209659762.sh知道jenkins執(zhí)行shell的原理后，接下來我們要談?wù)劷换ナ胶头墙换ナ絟ell、登錄和非登錄shelI之間的區(qū)別什么是交互式shell(interactiveshell)和非交互式shell(non-interactiveshell)交互式的shell會有一個輸入提示符，并且它的標(biāo)準(zhǔn)輸入、輸出和錯誤輸出都會顯示在控制臺上。這種模式也是大多數(shù)用戶非常熟悉的：登錄、執(zhí)行一些命令、退出。當(dāng)你退出后，shell也終止了。非交互式shell是bashscript.sK這類的shell。在這種模式下，shell不與你進(jìn)行交互，而是讀取存放在文件中的命令并且執(zhí)行它們。當(dāng)它讀

5、到文件的結(jié)尾EOF,shell也就終止了。什么是登錄式shell(loginshell)和非登陸式shell(no-loginshell)需要輸入用戶名和密碼的;hell就是登陸式shell。因此通常不管以何種方式登陸機(jī)器后用戶獲得的第一個hell就是loginshell。不輸入密碼的ssh是公鑰打通的，某種意義上說也是輸入密碼的。非登陸式的就是在登陸后啟動bash等，即不是遠(yuǎn)程登陸到主機(jī)這種。通過manbash了解loginshell和interactiveshell,如下INVOCATIONAloginshellisonewhosefirstcharacterofargumentzeroi

6、sa-,oronestartedwiththe-loginoption.Aninteractiveshellisonestartedwithoutnon-optionargumentsandwithoutthe-coptionwhosestandardinputanderrorarebothconnectedtoterminals(asdeterminedbyisatty(3),oronestartedwiththe-ioption.PS1issetand$-includesiifbashisinteractive,allowingashellscriptorastartupfiletotes

7、tthisstate.Thefollowingparagraphsdescribehowbashexecutesitsstartupfiles.Ifanyofthefilesexistbutcannotberead,bashreportsanerror.TildesareexpandedinfilenamesasdescribedbelowunderTildeExpansionintheEXPANSIONsection.Whenbashisinvokedasaninteractiveloginshell,orasanon-interactiveshellwiththe-loginoption,

8、itfirstreadsandexecutescommandsfromthefile/etc/profile,ifthatfileexists.Afterreadingthatfile,itlooksfor/.bash_profile,/.bash_login,and/.profile,inthatorder,andreadsandexecutescommandsfromthefirstonethatexistsandisreadable.The-noprofileoptionmaybeusedwhentheshellisstartedtoinhibitthisbehavior.Whenalo

9、ginshellexits,bashreadsandexecutescommandsfromthefile/.bash_logout,ifitexists.Whenaninteractiveshellthatisnotaloginshellisstarted,bashreadsandexecutescommandsfrom/.bashrc,ifthatfileexists.Thismaybeinhibitedbyusingthe-norcoption.The-rcfilefileoptionwillforcebashtoreadandexecutecommandsfromfileinstead

10、of/.bashrc.Whenbashisstartednon-interactively,torunashellscript,forexample,itlooksforthevariableBASH_ENVintheenvironment,expandsitsvalueifitappearsthere,andusestheexpandedvalueasthenameofafiletoreadandexecute.Bashbehavesasifthefollowingcommandwereexecuted:if-nH$BASH_ENV"then.H$BASH_ENV"fib

11、utthevalueofthePATHvariableisnotusedtosearchforthefilename.對manbash解讀：如果一個bash是交互式登錄Shell或者使用-login參數(shù)的非交互式Shell。首先會執(zhí)行/etc/profil咬件。然后按順序查按/.bash_profile,/.bash_login,-/.profile,這三個文件誰存在并且有讀權(quán)限就執(zhí)行誰，然后后面的就不會再執(zhí)行?？梢酝ㄟ^指定-noprofile參數(shù)來禁止這種默認(rèn)行為。當(dāng)?shù)卿汼hell退出之后，bash會讀取/.bashogou文件并執(zhí)行。如果/.bash_profile文件存在的話，一般還會執(zhí)

12、行/.bashr(文件。因為在/.bash_profile文件中一般會有下面的代碼：if-f/.bashrc;then./.bashrcfi/.bashrc中，一般還會有以下代碼：if-f/etc/bashrc;then./etc/bashrcfi所以執(zhí)行順序為：/etc/profile->(/.bash_profile|/.bash_login|/.profile)->/.bashrc->/etc/bashrc->/.bash_logout如果是一個交互式非登錄Shell,bash會讀取/.bashrc文件。同時，可以指定-norc參數(shù)來禁止該行為，或者通過-rcfi

13、le指定其它文件。如果是一個非交互式非登錄Shell,比如運(yùn)行一個Shell腳本，它會在環(huán)境查找BASH_ENV變量。通過上面的分析,對于常用環(huán)境變量設(shè)置文件,整理出如下加載情況表：文件非交互+登陸式交互+登陸式交互+非登陸式非交互+非登陸式/etc/profile加載加載/etc/bashrc加載加載/.bash_profile加載加載/.bashrc加載加載加載BASH_ENV加載執(zhí)行腳本，女Bbashscript.sS屬于non-login+non-interactive所以jenkins默認(rèn)情況下/bin/sh-xe/tmp/hudson224519953209659762.sh是屬于

14、non-login+non-interactive解決方案通過manbash可知：OPTIONSInadditiontothesingle-charactershelloptionsdocumentedinthedescriptionofthesetbuiltincommand,bashinterpretsthefollowingoptionswhenitisinvoked:-cstringIfthe-coptionispresent,thencommandsarereadfromstring.Ifthereareargumentsafterthestring,theyareassignedt

15、othepositionalparameters,startingwith$0.-iIfthe-ioptionispresent,theshellisinteractive.-lMakebashactasifithadbeeninvokedasaloginshell(seeINVOCATIONbelow).-rIfthe-roptionispresent,theshellbecomesrestricted(seeRESTRICTEDSHELLbelow).-sIfthe-soptionispresent,orifnoargumentsremainafteroptionprocessing,thencommandsarereadfromthestandardinput.Thisoptionallowsthepositionalparameterstobesetwheninvokinganinteractiveshell.-DAlistofalldouble-quotedstringsprecededby$isprintedonthestandardoutput.Thesearethestringsthataresubjecttolanguagetranslationwhe