Chapter 3. Usage

This chapter describes the necessary steps for rebuilding and using Red Hat Software Collections 3.0 Beta, and deploying applications that use Red Hat Software Collections.

3.1. Using Red Hat Software Collections

3.1.1. Running an Executable from a Software Collection

To run an executable from a particular Software Collection, type the following command at a shell prompt:
scl enable software_collection... 'command...'
Or, alternatively, use the following command:
scl enable software_collection... -- command...
Replace software_collection with a space-separated list of Software Collections you want to use and command with the command you want to run. For example, to execute a Perl program stored in a file named hello.pl with the Perl interpreter from the perl516 Software Collection, type:
~]$ scl enable rh-perl524 'perl hello.pl'
Hello, World!
You can execute any command using the scl utility, causing it to be run with the executables from a selected Software Collection in preference to their possible Red Hat Enterprise Linux system equivalents. For a complete list of Software Collections that are distributed with Red Hat Software Collections, see Table 1.1, “Red Hat Software Collections 3.0 Beta Components”.

3.1.2. Running a Shell Session with a Software Collection as Default

To start a new shell session with executables from a selected Software Collection in preference to their Red Hat Enterprise Linux equivalents, type the following at a shell prompt:
scl enable software_collection... bash
Replace software_collection with a space-separated list of Software Collections you want to use. For example, to start a new shell session with the python27 and rh-postgresql95 Software Collections as default, type:
~]$ scl enable python27 rh-postgresql95 bash
The list of Software Collections that are enabled in the current session is stored in the $X_SCLS environment variable, for instance:
~]$ echo $X_SCLS
python27 rh-postgresql95
For a complete list of Software Collections that are distributed with Red Hat Software Collections, see Table 1.1, “Red Hat Software Collections 3.0 Beta Components”.

3.1.3. Running a System Service from a Software Collection

Software Collections that include system services install corresponding init scripts in the /etc/rc.d/init.d/ directory. To start such a service in the current session, type the following at a shell prompt as root:
service software_collection-service_name start
Replace software_collection with the name of the Software Collection and service_name with the name of the service you want to start. To configure this service to start automatically at boot time, type the following command as root:
chkconfig software_collection-service_name on
For example, to start the postgresql service from the rh-postgresql95 Software Collection and enable it in runlevels 2, 3, 4, and 5, type as root:
~]# service rh-postgresql95-postgresql start
Starting rh-postgresql95-postgresql service:                  [  OK  ]
~]# chkconfig rh-postgresql95-postgresql on
For more information on how to manage system services in Red Hat Enterprise Linux 6, refer to the Red Hat Enterprise Linux 6 Deployment Guide. For a complete list of Software Collections that are distributed with Red Hat Software Collections, see Table 1.1, “Red Hat Software Collections 3.0 Beta Components”.

3.2. Accessing a Manual Page from a Software Collection

Every Software Collection contains a general manual page that describes the content of this component. Each manual page has the same name as the component and it is located in the/opt/rh directory.
To read a manual page for a Software Collection, type the following command:
scl enable software_collection 'man software_collection'
Replace software_collection with the particular Red Hat Software Collections component. For example, to display the manual page for rh-mariadb101, type:
~]$ scl enable rh-mariadb101 "man rh-mariadb101"

3.3. Deploying Applications That Use Red Hat Software Collections

In general, you can use one of the following two approaches to deploy an application that depends on a component from Red Hat Software Collections in production:
  • Install all required Software Collections and packages manually and then deploy your application, or
  • Create a new Software Collection for your application and specify all required Software Collections and other packages as dependencies.
For more information on how to manually install individual Red Hat Software Collections components, see Section 2.2, “Installing Red Hat Software Collections”. For further details on how to use Red Hat Software Collections, see Section 3.1, “Using Red Hat Software Collections”. For a detailed explanation of how to create a custom Software Collection or extend an existing one, read the Red Hat Software Collections Packaging Guide.

3.4. Red Hat Software Collections Container Images

Container images based on Red Hat Software Collections include applications, daemons, and databases. The images can be run on Red Hat Enterprise Linux 7 Server and Red Hat Enterprise Linux Atomic Host. For information about their usage, see Using Red Hat Software Collections 3 Container Images. For details regarding container images based on Red Hat Software Collections versions 2.4 and earlier, see Using Red Hat Software Collections 2 Container Images.
The following container images are available with Red Hat Software Collections 3.0 Beta:
  • rhscl-beta/devtoolset-7-toolchain-rhel7
  • rhscl-beta/devtoolset-7-perftools-rhel7
  • rhscl-beta/httpd-24-rhel7
  • rhscl-beta/mariadb-102-rhel7
  • rhscl-beta/mongodb-34-rhel7
  • rhscl-beta/nginx-112-rhel7
  • rhscl-beta/nodejs-8-rhel7
  • rhscl-beta/php-71-rhel7
  • rhscl-beta/postgresql-96-rhel7
  • rhscl-beta/python-36-rhel7
The following container images are based on Red Hat Software Collections 2.4:
  • rhscl/devtoolset-6-toolchain-rhel7
  • rhscl/devtoolset-6-perftools-rhel7
  • rhscl/httpd-24-rhel7
  • rhscl/nginx-110-rhel7
  • rhscl/nodejs-6-rhel7
  • rhscl/python-27-rhel7
  • rhscl/ruby-24-rhel7
  • rhscl/ror-50-rhel7
  • rhscl/thermostat-16-agent-rhel7
  • rhscl/thermostat-16-storage-rhel7
The following container images are based on Red Hat Software Collections 2.3:
  • rhscl/mysql-57-rhel7
  • rhscl/perl-524-rhel7
  • rhscl/php-70-rhel7
  • rhscl/redis-32-rhel7
  • rhscl/mongodb-32-rhel7
  • rhscl/php-56-rhel7
  • rhscl/python-35-rhel7
  • rhscl/ruby-23-rhel7
The following container images are based on Red Hat Software Collections 2.2:
  • rhscl/devtoolset-4-toolchain-rhel7
  • rhscl/devtoolset-4-perftools-rhel7
  • rhscl/mariadb-101-rhel7
  • rhscl/nginx-18-rhel7
  • rhscl/nodejs-4-rhel7
  • rhscl/postgresql-95-rhel7
  • rhscl/ror-42-rhel7
  • rhscl/thermostat-1-agent-rhel7
  • rhscl/varnish-4-rhel7
The following container images are based on Red Hat Software Collections 2.0:
  • rhscl/mariadb-100-rhel7
  • rhscl/mongodb-26-rhel7
  • rhscl/mysql-56-rhel7
  • rhscl/nginx-16-rhel7
  • rhscl/passenger-40-rhel7
  • rhscl/perl-520-rhel7
  • rhscl/postgresql-94-rhel7
  • rhscl/python-34-rhel7
  • rhscl/ror-41-rhel7
  • rhscl/ruby-22-rhel7
  • rhscl/s2i-base-rhel7