Why using a version control system?
- deploy by releases
- branch = code Stand: nur 1 branch auf dem alle arbeiten
- branches werden getaggt
- capability to rollback to a previous release
- problem unter produktion entdeckt - keine Zeit für Analyse
- Datensicherung: wiederherstellen nach Löschen von Dateien in einer Umgebung
- Verteilung
- Technische Übertragung auf mehrere Server
Scope
-3 environments: geht nicht mit weniger
- es muss eine Integrationsumgebung geben, damit das Deployment selber getestet werden kann
Regeln für den Umgang mit version control systemen
- Commit: ein funktionsfähiger und auslieferungsfähiger Stand, es darf kein Entwicklungsschritt committed werden
- Keine Commits zur Datensicherung
Probleme
- Korrekturlieferungen aus dev
- Keine selektiven Updates auf Verzeichnisebene
- Updates auf Verzeichnisebene: nein, da sonst Problem mit globalen Ressourcen, z.B. global locks, globale Prozessklassen
- Update immer auf live folder
- Keine selektiven Updates auf Änderungshistorie
- Es wird immer der aktuelle Stand des Repository übernommen, nicht ein bestimmter Revisionsstand
- Keine selektiven Updates auf Verzeichnisebene
- Disziplin:
- wenn derjenige, der in Integration testet, nicht wissen kann, was genau in der Lieferung enthalten ist, dann kann er nicht prüfen, ob er ggf. zu viele oder falsche Objekte erhalten hat
- Know How Auftrennnung: der Entwickler kennt Locks, der Tester kennt einen Testfall für Concurrency (nicht die Objekte, die das implementieren)
- Umgebungsspezifische Dateien
- Dürfen nicht committed werden
Deployment
The deployments from test to integration to production make use of the following steps
- copy the configuration files from one stage to the other
- do not copy the files that are used exclusively for testing in your test environment
- do not copy mock files
Just copying files probably is not sufficient. There are differences in the configuration that have to be considered.
- host names for process classes are different
- Solution: Having a set of process classes on each stage that will not be part of the deployment procedure. This configuration will be handled directly on the specific stage.
- different input for file order sources
- Solution: Having different file order sources on each stage that will not be part of the deployment procedure. This configuration will be handled directly on the specific stage.
- different values for parameters, e.g. database connection strings are different
- Make use of include files.
- Make use of environment variables that will be substituted at run time.
Using a version control software for deployment
When deploying configuration files it is more than just copying files from a to b. When working with sources a version control software migth be helpful. With a version control system
- you can rollback to an older version if neccessary
- changes are documented
- You have to commit changes that are relevant for other environments like integration or production
- You can exclude test configuration files by not adding them to the repository
This table describes the deployment with Git and Subversion.
Subversion | Git | ||
---|---|---|---|
Find the Subversion documentation from | The full Git documentation can be found here | ||
Pre Conditions | |||
Subversion Server Find the documentation „how to install a subversion server“ from http://svnbook.red-bean.com/en/1.8/svn.serverconfig.html | Git central repository. You can create a central repository with Navigate to a folder live where you want to locate the Git repository e.g. c:\temp\git_repro\live
| ||
Subversion client installed on local machine | Git client installed on local machine | ||
Subversion Projectarchive | |||
All files to be deployes are located in the live folder of a JobScheduler installation. | Creating a working copy in your Please note that after the import the | Creating a working copy in your live folder from the git repository | |
| navigate to your config folder move all files to a temporary folder
move all files back to the
| ||
| The files are now in the Subversion project archive. You can verify this with the command
| The files are now in the Git repository. You can verify this with cloning the repository to one more folder
| |
Delete the files from the live folder Execute the command checkout to get the files from the project archive to the live folder
| |||
Working with the project archive | You can have several working copies of the To synchronize changes in the working copy with the project folder there are two commands | You can have several working copies of the To synchronize changes in the working copy with the project folder there are three commands | |
Read the current version from the project archive (update) The update command reads changes from the project archive and merge them into the working copy.
| Read the current version from the repository (pull)
| ||
The Please note that before commiting changes a update command is neccessary especially when a commit from another working copy has been executed.
| The push command writes committed changes from the working copy to the repository
| ||
Making changes | Changes are applied to the working copy by use of JOE or a text editor software. When all changes for certain approach has been done the changes can be commited to the project archive. Before carrying out the
| Changes are applied to the working copy by use of JOE or a text editor software.
| |
Deployment | There are two possible architectures to organize the deployment:
| ||
Consider environment specific parameters and configurations
When doing the deployment it is possible that parameter values are not valid in integration/production environments, e.g. the names of files, folders, printers etc.
Use environment variables that accept different values in development, integration and production environments. For
- File order sources
- Directories in file names
<job_chain name="job_chain1"> <file_order_source directory="${file_input_dir}\input" regex=".*"/> ... </job_chain>
Use include files to specify parameter values:
<order> <params> <include live_file="myorder.params.xml" node=""/> .. </order>
where the file myorder.params.xml could look like this:
<params > <param name="par1" value="value1"/> <param name="par2" value="value2"/> </params>
Use different script include files for development, integration and production environments:
<job order="yes"> <script language="shell"> <include live_file="include_scriptfile.sh"/> </script> <run_time /> </job>
How to handle different include files for parameters and scripts
- create a folder include_files (parallel to the
live
folder) - create subfolders for dev, int and prod
- create the same subfolders under dev, int and prod as in the
live
folder - create the include files in the subfolders for dev, int and prod
- create a projectarchive wich contains the folder include_file
- create a working copy with the import, delete and checkout command (see above).
- When committing the include_files folder you should also commit the live folder (and vica versa) to have consistency between both folders.
- When deploying to int export the include_files/int folder to the live folder at int
- When deploying to prod export the include_files/prod folder to the live folder at prod
As you have a working copy in the live folder of dev, the include files from dev will be deployed when exporting the dev live folder. But with the second export from the include_files folder, the dev files will be overwritten with the correct version. An alternative approach is that also the live folder in dev is not a working copy but will be actualized with an export command from the dev working copy.
The quality of the development environment
When having some test configuration files in the development environment you should take care not to commit them to the repository. To achieve this, no add
command should be executed on these files. You also can add these files to an ignore list (available with Git and Subversion). You should take into account that each configuration item that has been committed to the repository will be deployed to the integration or production environments some time later.
Rollback to a previous version
To rollback to a previous version
- identify the release to which you want to fall back
- With Subversion/Git commands get the files of the release
- Publish these files to int/prod