Linux – My Shitty Code

RPM: Performing Offline Installation

Shitty Author — Sun, 05 Jul 2020 00:34:40 +0000

PROBLEM

To perform an offline (or airgapped) installation, sometimes it’s not sufficient to download just the needed RPM package. In most cases, this package requires a list of dependencies to be installed too.

For example, Nginx requires at least 20 different packages in order for its installation to be successful:-

$ sudo yum deplist nginx
package: nginx.x86_64 1:1.16.1-1.el7
  dependency: /bin/sh
   provider: bash.x86_64 4.2.46-34.el7
  dependency: libc.so.6(GLIBC_2.17)(64bit)
   provider: glibc.x86_64 2.17-307.el7.1
  dependency: libcrypt.so.1()(64bit)
   provider: glibc.x86_64 2.17-307.el7.1
  ...
  ...
  ...
  dependency: system-logos
   provider: redhat-logos.noarch 70.7.0-1.el7
  dependency: systemd
   provider: systemd.x86_64 219-73.el7_8.8

SOLUTION

The first step to spin up an instance using the same Linux distro/version and this instance must have internet access.

Download the following yum plugin that allows the package(s) to be downloaded without installing them:-

sudo yum install yum-plugin-downloadonly

Download the needed package (in this case, Nginx) and its dependencies into a directory:-

sudo yum install --downloadonly --downloaddir=/tmp/nginx nginx

To inspect what’s being downloaded:-

$ ls -a /tmp/nginx | sort
.
..
dejavu-fonts-common-2.33-6.el7.noarch.rpm
dejavu-sans-fonts-2.33-6.el7.noarch.rpm
fontconfig-2.13.0-4.3.el7.x86_64.rpm
fontpackages-filesystem-1.44-8.el7.noarch.rpm
gd-2.0.35-26.el7.x86_64.rpm
gperftools-libs-2.6.1-1.el7.x86_64.rpm
libjpeg-turbo-1.2.90-8.el7.x86_64.rpm
libX11-1.6.7-2.el7.x86_64.rpm
libX11-common-1.6.7-2.el7.noarch.rpm
libXau-1.0.8-2.1.el7.x86_64.rpm
libxcb-1.13-1.el7.x86_64.rpm
libXpm-3.5.12-1.el7.x86_64.rpm
nginx-1.16.1-1.el7.x86_64.rpm
nginx-all-modules-1.16.1-1.el7.noarch.rpm
nginx-filesystem-1.16.1-1.el7.noarch.rpm
nginx-mod-http-image-filter-1.16.1-1.el7.x86_64.rpm
nginx-mod-http-perl-1.16.1-1.el7.x86_64.rpm
nginx-mod-http-xslt-filter-1.16.1-1.el7.x86_64.rpm
nginx-mod-mail-1.16.1-1.el7.x86_64.rpm
nginx-mod-stream-1.16.1-1.el7.x86_64.rpm
redhat-indexhtml-7-13.el7.noarch.rpm

Now, this directory can be safely compressed into a tarball to be copied to the target instance without internet access.

After extracting the tarball in the target instance, it’s time to install the package:-

sudo yum -y --disablerepo=* localinstall /tmp/nginx/*.rpm

This command is smart enough to figure out all the dependencies within the directory and install them in the proper order.

The post RPM: Performing Offline Installation appeared first on My Shitty Code.

tar: Exiting with failure status due to previous errors

Shitty Author — Mon, 12 Jun 2017 14:57:21 +0000

PROBLEM

When creating a compressed archive file:-

tar -zcvf apps.tar.gz apps

… the following error is thrown:-

tar: Exiting with failure status due to previous errors

SOLUTION

This error usually occurs due to permission issues.

However, the error messages are hidden beneath gobs of output activated by the verbose flag.

To fix this, reduce the output by removing the -v flag:-

tar -zcf apps.tar.gz apps

… and now, the error message appears:-

tar: apps/apps.key.enc: Cannot open: Permission denied
tar: Exiting with failure status due to previous errors

Once the problem is fixed, the command will run successfully.

The post tar: Exiting with failure status due to previous errors appeared first on My Shitty Code.

Git + Linux: (gnome-ssh-askpass:24871): Gtk-WARNING **: cannot open display:

Shitty Author — Mon, 12 Sep 2016 16:11:10 +0000

PROBLEM

When running git clone on Linux, the following error appears:-

-bash-4.1$ git clone http://user@tfs:8080/tfs/my-institution/my-domain/_git/my-project
Initialized empty Git repository in /people/my-group/user/my-project/.git/

(gnome-ssh-askpass:24871): Gtk-WARNING **: cannot open display:

SOLUTION

To fix this, run the following command to disable gnome-ssh-askpass:-

-bash-4.1$ unset SSH_ASKPASS

Now, git clone will work just fine:-

-bash-4.1$ git clone http://user@tfs:8080/tfs/my-institution/my-domain/_git/my-project
Initialized empty Git repository in /people/my-group/user/my-project/.git/
Password:
remote:
remote:                    fTfs
remote:                  fSSSSSSSs
remote:                fSSSSSSSSSS
remote: TSSf         fSSSSSSSSSSSS
remote: SSSSSF     fSSSSSSST SSSSS
remote: SSfSSSSSsfSSSSSSSt   SSSSS
remote: SS  tSSSSSSSSSs      SSSSS
remote: SS   fSSSSSSST       SSSSS
remote: SS fSSSSSFSSSSSSf    SSSSS
remote: SSSSSST    FSSSSSSFt SSSSS
remote: SSSSt        FSSSSSSSSSSSS
remote:                FSSSSSSSSSS
remote:                  FSSSSSSs
remote:                    FSFs    (TM)
remote:
remote:  Microsoft (R) Visual Studio (R) Team Foundation Server
remote:
Receiving objects: 100% (504/504), 1.05 MiB, done.
Resolving deltas: 100% (138/138), done.

To prevent this from happening again, add unset SSH_ASKPASS command to .bashrc file.

The post Git + Linux: (gnome-ssh-askpass:24871): Gtk-WARNING **: cannot open display: appeared first on My Shitty Code.

Linux: Locating Java Home Directory

Shitty Author — Wed, 12 Mar 2014 14:48:05 +0000

If you have multiple versions of Java installed, you can run which command to determine the full path of the command.

which java

To quickly navigate to Java’s home directory, you can do something like this:-

cd `which java`/..

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