Development & Infrastructure - Hints and Tips

This post contains general bits and pieces that I’ve come across over the years, which don’t necessarily warrant a full blog posting. I’ll keep updating this as I go…

Solaris

• Solaris 9: Enable core dumps:

  coreadm -e process 
  coreadm -i /var/core/core_%n_%f_%u_%g_%t_%p 
  

  Where:

  %n = System name 
  %f = Executable file name
  %u = User ID 
  %g = Group ID 
  %t = Decimal value of time 
  %p = Process ID 
  

• Solaris: NFS mount gives “No such file or directory” on the solaris client, edit /etc/default/nfs, and make sure to set NFS_CLIENT_VERSMAX=3.
• Solaris 10: network service management:

  List services: svcs
  e.g. output:
  online         14:52:15 svc:/network/svn/tcp:default
  online         Jun_13   svc:/network/ftp:default
  
  Stop service: svcadm disable svc:/network/ftp
  Start service: svcadm enable svc:/network/ftp
  Delete service: svccfg delete svc:/network/ftp
  

  Solaris Service Management HowTo
• Solaris 9: show PIDS listening on a port (e.g: 35302):

  ps -ef| awk '{print $2}'| xargs -I '{}' sh -c 'echo examining process {}; pfiles {}| grep "port: 35302$"'
  

• Solaris 10: Oracle 10g Full 64bit client install problems Log file shows:

  ld.so.1: proc: fatal: /space/oracle/ora9i/lib32/libclntsh.so.9.0: wrong ELF class: ELFCLASS32
  

  Do this after the install:

  export LIB_LIBRARY_PATH=$ORACLE_HOME/lib:$ORACLE_HOME/lib32:$LIB_LIBRARY_PATH
  #Setup the environment manually, e.g:
  export ORACLE_HOME=/opt/oracle/product/10.2.0/client_1
  export LD_LIBRARY_PATH=$ORACLE_HOME/lib
  export PATH=$PATH:$ORACLE_HOME/bin
  cd :$ORACLE_HOME/bin ; ./relink all
  

• Solaris 9: List threads - http://www.unix.com/programming/9397-count-number-threads-process.html

  ls /proc/*/lwp
  

  * being the pid of the application. This also works:

  ps -efL
  

• Solaris 9: Add a package, as root e.g:

  pkgadd -d ./curl-7.21.6-sol9-sparc-local
  

AIX

• NFS mount gives “mount: giving up on…vmount: Not owner” on AIX, run the following and then try again

  nfso -o nfs_use_reserved_ports=1
  

• AIX: gcc compile complains:

  ld: 0711-317 ERROR: Undefined symbol: __crypt_r
  ld: 0711-317 ERROR: Undefined symbol: __setkey_r
  ld: 0711-317 ERROR: Undefined symbol: __encrypt_r
  

  If symbols such as these are definitely not used and you want to ignore them, create a file, e.g crypt.exp with the contents between START/END:

  #!
  __crypt_r
  __encrypt_r
  __setkey_r
  

  Then add the following to your Makefile CFLAGS: -Wl,-bI:crypt.exp -fPIC
• AIX: login always gives - “3004-610 You are required to change your password.”. Clear password flag: pwdadm -c myuser

Linux

• How to forward X when sudo to a different user

  you@server$ xauth list
  [output]
  you@server$ sudo su - otheruser
  otheruser@server$ xauth add [paste output from "xauth list"]
  otheruser@server$ xterm (or other X application)
  

• Linux kernels 2.x hard-reset:

  echo 1 > /proc/sys/kernel/sysrq
  echo b > /proc/sysrq-trigger
  

• RHEL 7.x: mount smbfs, Windows file share:

  mount -t smbfs -o username=myUser,workgroup=myDomain //nas/someFolder /mnt/nas
  

• RHEL 6.x: enable FTP Access when SELinux is an issue:

  /usr/sbin/setsebool -P ftp_home_dir=1
  /usr/sbin/setsebool -P allow_ftpd_full_access=1
  

• Redhat 5.x: force disk check on reboot (as root):

  touch /forcefsck
  

• Linux, kill an open socket:

  fuser -k -n tcp 37
  

• Linux kernel 2.6 core dump enable:

  mkdir /var/core
  chmod 0777 /var/core/
  echo /var/core/core.%e.%p > /proc/sys/kernel/core_pattern
  ulimit -c unlimited
  

• Run a program via the Linux Valgrind profiler to check for leaks/issues:

  valgrind --leak-check=full -v --track-origins=yes --show-reachable=yes ./myApp.Linux -someAppargs
  

• Linux 2.6+ kernel settings to mitigate TIME_WAIT issues visible in netstat (remember to update /etc/sysctl.conf)

  echo 1 > /proc/sys/net/ipv4/tcp_tw_recycle
  echo 1 > /proc/sys/net/ipv4/tcp_tw_reuse
  echo 30 > /proc/sys/net/ipv4/tcp_fin_timeout
  

• Linux show process threads: ps -elfT
• RHEL 6: Install alternative e.g javac: alternatives --install /usr/bin/javac javac /usr/java/latest/bin/javac 3
• RHEL 6: Configure alternatives e.g java: alternatives --config java

UNIX General

• Find extended non-ASCII characters in a file

  grep --color='auto' -P -n "[\x80-\xFF]" ./file.txt
  

• Extract a cpio file: cpio -idmv < file
• Vim tips

  vim Bracket matching
  Shift-%
  :syntax on
  # vim enable mouse pointing
  set mouse=a
  # Pasting a block of code copied from elsewhere in Vim can be a pain. The autoindent (and, possibly, smartindent) features of Vim go crazy when you yank and slap a block of text, so:
  set pastetoggle=
  # that way you can turn auto indenting for pastes on and off with one press of a key. Basically pastetoggle takes care of “:set paste” “:set nopaste”
  

• OpenSSL: How to show an SSL certificates contents:

  cat client.pem | openssl x509 -noout -text
  

• Net-SNMP: Generate .index file for mib names and files

  #!/bin/bash
  rm idx
  for file in `ls *.mib`
  do
    name=`grep ' DEFINITIONS ::= BEGIN' $file | awk {'print $1'}`
    echo $name $file >> idx
  done
  

• Create a tar with in input file list:

  cat list.txt|xargs tar cf archive.tar
  

• Net-SNMP: Create a MIB= list from a bunch of mib files:

  grep BEGIN ./*.txt | sort | uniq | awk -F':' {'print $2'} | grep -v 'BEGIN' | awk {'print $1'} > list
  for file in `cat list`
  do
  name=$name:$file
  done
  echo $name
  

• Check CPU endianness where 0=big, 1=little:

  echo I | tr -d [:space:] | od -to2 | head -n1 | awk '{print $2}' | cut -c6 
  

  Solaris SPARC: big
  AIX PPC: big
  Linux x86_x64: little
  s390x: big
• Get libc version:

  Linux RHEL/CentOS: rpm -qa|grep -i glibc
  Linux others: /lib/libc.so.6
  Others: strings /lib/libc.so.6 | grep GLIB
  

Windows

• Create a Windows service from the cmd prompt:

  sc create "MyService"" binpath= "\"C:\Program Files\MyCompany\MyService\bin\myExecutable.exe\"" displayname= "My Service" start= auto obj= LocalSystem
  

• Windows “Edit plan settings” opens every time I click enter - Press: windows-key x
• Windows EventViewer Security log logon check query for a time period:

  <QueryList>
    <Query Id="0" Path="Security">
      <Select Path="Security">
  *[System[(EventID=4624)
  and
      TimeCreated[timediff(@SystemTime) &lt;= 2592000000]]
  and
      EventData[Data[@Name='LogonType'] and (Data='10' or Data='2' or Data='7' or Data='3')]
  and
      EventData[Data[@Name='TargetUserName'] and (Data='someDomainUser')]
  ]
  </Select>
    </Query>
    <Query Id="0" Path="Security">
      <Select Path="Security">
  *[System[(EventID=4634)
  and
      TimeCreated[timediff(@SystemTime) &lt;= 2592000000]]
  and
      EventData[Data[@Name='LogonType'] and (Data='10' or Data='2' or Data='7' or Data='3')]
  ]
  </Select>
    </Query>
  </QueryList>
  

Network

• Packet sniff on a UNIX/Linux box:

  /usr/local/sbin/tcpdump -s 1500 -w /tmp/pcap.dmp "host 10.0.0.220 and port 1234"
  

  load pcap.dmp in to Wireshark on Windows to view/search contents easily
• Missing “UNIX attributes” tab when setting up NIS on Windows 2008 domain controller:

  cd C:\Windows\idmu\common
  net stop “server for nis”
  regsvr32.exe /u nisprop.dll
  regsvr32.exe nisprop.dll
  net start “server for nis”
  

Programming Misc

• C FAQ - http://www.c-faq.com/
• Online ISO/ANSI C reference: http://www.opengroup.org/onlinepubs/009695399/idx/index.html
• .NET show exe/dll headers:

  dumpbin YourProgram.exe /headers
  

• .NET assembly table editor, orca:

  C:\Program Files (x86)\Microsoft SDKs\Windows\v7.0A\Bin\Orca.msi
  

• Disable advertised shortcuts in .msi Windows installer:

  cscript "C:\Program Files (x86)\Windows Installer 4.5 SDK\SAMPLES\SCRIPTS\WiRunSQL.vbs" "$(BuiltOuputPath)" "INSERT INTO Property(Property, Value) VALUES ('DISABLEADVTSHORTCUTS', '1')"
  

• Running Powershell script shows: cannot be loaded because the execution of scripts is disabled on this system. As administrator run powershell and then enter: Set-ExecutionPolicy RemoteSigned
• SVN import project:

  svn import -m "Initial import for JIRA-123" myApp svn://svnserver/applications/myApp
  

• Apache Karaf jmx location for jconsole: service:jmx:rmi:///jndi/rmi://localhost:1099/karaf-root
• Gradle: Skip tests: gradle build -x test
• Git: Remove all refs to a file locally:

  git filter-branch --force --index-filter "git rm --cached --ignore-unmatch src/test/resources/config.properties" --prune-empty -- --all
  

• Maven: set project and sub-modules version Using release plugin:

  mvn release:update-versions -DautoVersionSubmodules=true -DdevelopmentVersion=1.6.0-SNAPSHOT
  

  Using versions plugin:

  mvn versions:set -DnewVersion=1.6.3-SNAPSHOT
  

Database

• MS SQL Server 2008: Delete inuse DB:

  osql -E
  use master
  go
  alter database [besrep] set single_user with rollback immediate
  go
  drop database besrep
  go
  

• MS SQL Server 2008: drop multiple tables like:

  DECLARE @sql NVARCHAR(MAX) = N'';
  SELECT @sql += '
  DROP TABLE ' 
      + QUOTENAME(s.name)
      + '.' + QUOTENAME(t.name) + ';'
      FROM sys.tables AS t
      INNER JOIN sys.schemas AS s
      ON t.[schema_id] = s.[schema_id] 
      WHERE t.name LIKE 'ISS_PR_%';
  PRINT @sql;
  EXEC sp_executesql @sql
  

• IBM DB2: diagnostic messages - These are usually found under the DB2 server/ client install ($DB2PATH) ./sqllib/db2dump/db2diag.log
• Sybase ASE 15 Linux: error “os_create_region…”

      os_create_region: can't allocate 355016704 bytes 00:00:00000:00000:2011/05/13 10:56:35.54 kernel kbcreate: couldn't create kernel region. 00:00:00000:00000:2011/05/13 10:56:35.54 kernel kistartup: could not create shared memory
  

  Fix by increasing kernel.shmmax, e.g

  /sbin/sysctl -w kernel.shmmax=700000000
  # Also set: /etc/sysctl.conf:kernel.shmmax=700000000
  

Virtualisation

• XenServer 6.x: mount a disk as local ext based storage Go to the console in XenCenter, prepare new partition with fdisk and then:

  xe sr-create type=lvm content-type=user device-config:device=/dev/disk/by-id/DISK name-label="LOCAL SR"
  

• XenServer 6.x: set VM timeoffset: Get the uuid from: xe vm-list

  xe vm-param-set platform:timeoffset=0 uuid=53e7b30b-3f15-f5cc-d9ec-ee64ccbed52d
  

• Docker: remove all IMAGES: docker rmi $(docker images -qf “dangling=true”)
• Docker: delete all docker images: docker rmi $(docker images -q)
• Docker: kill and REMOVE all containers: docker rm $(docker kill $(docker ps -aq))
• Docker: attach and start shell: docker exec -i -t loving_heisenberg bash