I often find the quote "InstallUtil.exe" is an ugly pattern or "Don't use InstallUtil.exe" and that I should use native WIX or Installation package patterns and I still don't understood why.
I stepped away from using InstallUtil to install a .NET service as I finally learnt that writing registry keys for such an action should be an un-install-able action - and I've come to terms with this as correct.
As I've been working through my WIX installer for a relatively complex product, I have found myself in need of creating or updating SQL Server databases, creating or updating IIS Applications and finally updating or creating configuration files.
Each of my components (features) are optional, but they all share the same configuration file. As my product uses unity, its important to note that this library contains strong support for reading/updating/removing components from the Unity Configuration block, therefore it seems fairly smart to me that I should take advantages of these blocks via Installation Components (i.e. InstallUtil) to create or update my configuration file at installation time.
Just to be clear here, my installer does not natively contain a configuration file for my application: at installation time, the installer has no idea as to the shape of it as its based on the features selected. Surely I should be embedding this knowledge into each of the modules that are to be deployed and not in the remit of the installer which is now a completely independent project? Wouldn't this break O-O principals even if we are talking about installation?
I'd really appreciate some guidance as to whether this is good practise or not? Am I reading 'InstallUtil' is bad for installing services, or is it that using 'InstallUtil' is bad full-stop? If so, what are my options for smart updating of configuration files?
The main reason for avoiding InstallUtil is that it runs outside of the installation transaction, so Windows Installer cannot keep track of what it's done.
I have used InstallUtil on a few occasions, when I just couldn't get Wix to do what I needed and didn't have time to write a custom action. In this case I called the InstallUtilLib version as I feel this is a cleaner approach.
I used the this blog as a guide as to how to achieve this.
Many programs include an auto-updater, where the program occasionally looks online for updates, and then downloads and applies any updates that are found. Program bugs are fixed, supporting files are modified, and things are (usually) made better.
Unfortunately no matter how hard I look, I can't find information on this process anywhere. It seems like the auto-updaters that have been implemented have either been proprietary or not considered important.
It seems fairly easy to implement the system that looks for updates on a network and downloads them if they are available. That part of the auto-updater will change significantly from implementation to implementation. The question is what are the different approaches of applying patches. Just downloading files and replacing old ones with new ones, running a migration script that was downloaded, monkey patching parts of the system, etc.? Concepts are preferred, but examples in Java, C, Python, Ruby, Lisp, etc. would be appreciated.
I think that "language agnostic" is going to be a limiting factor here. Applications come in so many shapes and sizes that there is no one-size-fits-all answer. I have implemented several auto-updaters in several languages, and no two were similar.
The most general philosophy is that the application checks with some home location (web address, web query, corporate network location, etc.) to either ask if it's version is current, or ask what the most current version is. If the answer calls for an update, that process will be different for each situation.
A popular alternative is to invite the home location to run a script when the application is initiated. The script can check the version, download updates if necessary, and ask for usage feedback, for example.
We can probably help better if you narrow the parameters.
UPDATE: The approach to "patching" also depends on the nature of the application, and there's a very wide diversity here. If you have a single executable file, for instance, then it's probably most practical to replace the executable. If your application has many files, you should look for ways to minimize the number of files replaced. If your application is highly customized or parameterized, you should strive to minimize the re-tailoring effort. If your application employs interpreted code (such as an Excel VBA application or MS Access MDB application), then you may be able to replace parts of the code. In a Java application you may only need to replace a JAR file, or even a subset of the JAR contents. You'll also need to have a way to recognize the current client version, and update it appropriately. I could go on and on, but I hope you see my point about diversity. This is one of those many times when the best answer usually starts with "Well, it depends ...!" That's why so many answers include "Please narrow the parameters."
Be sure to also consider the security implications of sucking down information about the update, as well as the update binaries themselves.
Do you trust the source of the download? You maybe phoning home to got your update, but what if there is a man in the middle who redirects to a malicious server. An HTTPS or similar secure connection will help, but double checking the bits that you eventually download by using a digital signature check is recommended.
First you need a file on your application home web site with the latest version.
The best way I think to have special SQL table for this task and populate it automatically after publishing new version / nightly build completion.
Your application creates new thread which requests built-in http link with version and compares in with current. In .NET use can use code like this:
Version GetLatestVersion() {
HttpWebRequestrequest = (HttpWebRequest)WebRequest.Create(new Uri(new Uri(http://example.net), "version.txt));
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
if (request.HaveResponse)
{
StreamReader stream = new StreamReader(response.GetResponseStream(), Encoding.Default);
return new Version(stream.ReadLine());
}
else
{
return null;
}
}
Version latest = GetLatestVersion();
Version current = new Version(Application.ProductVersion);
if (current < latest)
{
// you need an update
}
else
{
// you are up-to-date
}
In this example, version.php in only one plain string like 1.0.1.0.
Another tip I can give - how to download an update.
I like very much next idea: in the resources of your application there is a string of CLR-code which you compile on-the-fly (using CodeDom) to a temporary folder, main application calls it and goes to close. Updater reads arguments, settings or registry and downloads new modules. And calls main application which deletes all temporary files. Done!
(But everything here is about .NET)
The simplest solutions (used by many programs) is running the uninstaller for the previous version and the running the installer for the new one (optionally skipping questions which the user has already answered, like the EULA). The only catch is that the new version must be able to read the configuration options from the old version.
Also, on Windows you can't delete an executable file which is in use, so you probably will want to drop a small executable in Temp folder, which runs the whole process and then delete it at the end from the instance of the new version which got launched (or just register it to be deleted at the next reboot).
Because auto updating is a common scenario, most languages have at least one package available to support this. (Below I list some of the available packages)
One of the really nice idea's is the ClickOnce distribution for .NET, it's an installer which sandboxes your application and installs in the user context, so no administrator rights required. You can configure the ClickOnce in your publish to check for updates each application start.
Java has Java Web Start which offers the same kind of functionality for java applets.
Delphi has numerous articles about auto-updating, Torry has a list of WebUpdate components, for instance GoUpdater seems to have a very wide range of functionality.
They all use a website/network share to check for a new version and than retrieve either a patch or a complete install file and run it. So you should try to find a nice package for your application, to save you the hassle of developing and maintaining your own solution.
The simplest approach would be to have your program query a server (website) to see if there is an update. If there is an update you could display a message to the user that prompts them to download a newer version and provides a link.
An alternative and more complex solution would be to create a small windows service (or unix daemon) that checks periodically to see if there are updates, this service can download the update and launch the installer.
The general architecture is that you have a central server that you control that knows the latest version and where to get it. Then the programs query the server. I am not going to include sample code because it is highly defendant on the server and the format you choose. It is not terrible difficult though.
This is not so much a complete answer, but rather one example of auto-updating mechanism I implemented recently. The situation is a little different from the tradition Firefox-type of user application, since it was an internal tool used at work.
Basically, it's a little script that manages a queue of Subversion branches to be built and packaged in an installer. It reads a little file, where the names of the branches are written, takes the first one, re-writes it at the end of the file, and launches the build process, which involves calling a bunch of scripts. The configuration for each branch to build is written in a .INI file, stored in a Subversion repository along with the tool itself.
Because this tool runs on several computers, I wanted a way to update it automatically on all machines as soon as I made a change either to the tool itself, or to the configuration scripts.
The way I implemented it was simple: when I launch the tool, it becomes an "outer shell". This outer shell does 2 very simple things:
svn update on itself and on the configuration files
launch itself again, this time as the "inner shell", the one that actually handles one configuration (and then exits again).
This very simple update-myself-in-a-loop system has served us very well for a few months now. It's very elegant, because it is self-contained: the auto-updater is the program itself. Because "outer shell" (the auto-updater part) is so simple, it doesn't matter that it does not benefit from the updates as the "inner shell" (which gets executed from the updated source file every time).
One thing that hasn't really been mentioned is that you should seriously consider that the user running your program might not actually have sufficient privileges to upgrade it. This should be pretty common at least for business users, probably less so for home users.
I'm always working with a (self-imposed) limited account for security reasons and it always pisses me off that most auto-updaters simply assume that I'm running as admin and then after downloading just fail and offer no other way of performing the update other than actually closing the program and running it again in an administrative context. Most do not even cache the downloaded update and have to do it all over again.
It'd be much better if the auto-updater would simply prompt for admin credentials when needed and get on with it.
I'm going to assume answer for Windows.
This way seems to work well.
In the installer do:
1. Create a manual-start service that runs as LocalSystem that when started does the update then stops.
2. Change the service permissions so all users can start the service (if all users should be able to update w/o admin rights).
3. Change the main program to check for updates when started using a simple mechanism. If it detects an update, prompt if the user wants to apply it.
4. If user accepts the update, start the service.
If the architecture allows for it, create a way to monitor the update as it is running.
In a Java-Webstart setting you start a JNLP file which then triggers the download of the Jar files needed to run the application. Everytime webstart checks if there are newer versions of the Jars and would download them replacing the locally cached ones. With a tool named jardiff you will create only diffs towards the newer jars and distribute these via the server (e.g. only get an update).
Pros:
always up to date
Cons:
you need an application server (tomcat, JBoss) in order to distribute the files
you need an internet connection in order to get the application
Reading Carl Seleborgs answer gave me some ideas how a generic code-repository could be useful.
svn comes with a tool called svnsync, which sort of behaves like an svn export but keeps track of the actual revision your export is at.
Someone could utilize this system in order to only fetch the changed files from the users actual revision.
In actuality, you will have a repository with the binaries compiled, and running svnsync will only fetch the binaries that has been modified. It might also be able to merge local changes to text-based configuration files with new configuration-options.
The function of installing a patch to a program is basically one of the basic functions of an installer. Installer software is documented in numerous places but usually on a per-installer basis: There the Microsoft Installer (with Install Shield Extensions), Ruby gems, Java .jar files, the various Linux package manager systems (RPM, Apt-get)and others.
These are all complex systems which solve the problem of patching program in general but for slightly different systems. To decide what is best for you, consider which of these system your application most resembles. Rolling your own is fine but looking at these systems is a place to start.
You can write an internal module of your application to do updates. You can write an external mini application to do updates.
Also look at .NET on-the-fly compilation technology, it makes possible to create such mini application on-the-fly on demand. For example, http://fly.sf.net/
You can use my solution (part of the Target Eye project).
http://www.codeproject.com/Articles/310530/Target-Eye-Revealed-part-Target-Eyes-Unique-Auto
If your software is open sourced, and target Linux or developers. It is interesting to install your software as a git repo. And having it pull the stable branch occasionally or everytime when it is launched.
This is particular easy when your application is managed via npm, sbt, mavan, stack, elm-package or alike.
After hours of searching some working solution for this problem I've finally implemented auto update mechanism for python script that works on Linux and Windows.
In short - the script before running actual work checks for update on S3 and if it's available downloads it, unzips, creates or updates the symlink (or junction on Windows) and re-runs the script with already the new version with original arguments.
The full source code and the explanation can be found here.
If you are searching for an cross-platform software update solution, take a look at www.updatenode.com
Some highlights:
free for Open Source projects
cross-platform & Open Source update client tool
localized already for the most important languages
easy to integrate and easy to handle
cloud based management platform to define and manage updates
provides additionally support for displaying messages (inform about new events, products, etc.)
web interface is open (you can create your own client using the service)
many usage statistics, as used operating systems, geo location, version usage, etc.
Android API for mobile App updates
Just try it.
BTW, I am part of the dev team for the open source client. :)
I am currently trying to use NAnt and CruiseControl.NET to manage various aspects of my software development. Currently, NAnt handles just about everything, including replacing environment specific settings (e.g., database connection strings) based on an input target that I specify on the command line.
CruiseControl.NET is used to build the application for the default environment (dev) anytime new code is committed. I also want CruiseControl.NET to invoke a build for my additional environments test and stage, but I do not want these to be automatically invoked every time that a dev build invoked (daily) as test and stage deployments happen far less frequently. Test and stage deployments only occur when the application is ready for QA.
I can easily do this by specifying multiple projects, one for each environment. However, I already have many projects configured, one for each milestone in within my application. If I have to setup 3 projects for each milestone the CruiseControl.NET configuration can get out of hand quickly.
Here is my question:
Can I parameterize a CruiseControl.NET project configuration such that the parameters are exposed by the web interface?
Preferably (I think), I could have checkboxes for each environment (e.g., dev, test, stage) exposed in the web interface. A build would be made for each environment that is checked, whether the build was forced or automatic. It would be even better if I could default the checked state.
This feature (Dynamic Build Parameters) is currently being worked on for 1.5, and you can try it out in the nightlies. Here's a post describing the feature.
As Scott has mentioned, this isn't available, but it wouldn't take too much just to write a little template and then auto-generate the ccnet.config file given that template and a list of environments in a mail-merge type way.
Unfortunately, you can't do anything like that with CruiseControl.NET. It's a good idea, so you might want to submit it as a feature request.
This is fully supported now starting with cruisecontrol 1.5: http://cruisecontrolnet.org/projects/ccnet/wiki/Parameters
To get an application installed on a new computer there seems to be two major approaches in current use:
Separate installer: Create a separate installer package
that creates all directories, files,
registry entries required by your
application (ie an MSI, InstallSheild etc) and then finally copies your application to the target computer.
Self installer: Include all required
installation steps in a component
that is part of your application. Then use this component to check and create required settings each time the main application executable is run. ie Just run the application to install.
I've used a few applications that corrupt their settings over time, and most had a separate installer. Therefore the only fix was to to re-install, sometimes with settings and even data being lost (very frustrating).
Also during software projects I've worked on, the separate installer approach often dictated spreading application specific knowledge across both the installer package and the actual application. Then, when code/functionality changes were made, both the installer and app needed to be updated. It always felt a bit too brittle and prone to human error.
So I'm currently leaning toward the self installer approach because of a simpler more robust installation/setup, ie just run the app. This self installing approach I feel would also lend itself a more robust application.
Integration with in application settings (options) would also be much more clean, in many cases the same component could perform both installation and settings management.
On the negative, however, performing these extra checks/steps each time the app starts might negatively impact startup times, and OS integration might be a bit more work then using a standard installer.
So which approach to people recommend and why?
(I'm most interested in installation of desktop rich client applications at present.)
There are pros and cons to both approaches:
Having an installer is the proper way to install necessary system components, like drivers, libraries, COM components and so on. Since many of these activities need elevated permissions the install may be performed by the administrator, while the application can be used by all users.
There may actually be requirements for a scriptable installation procedure in corporate environments.
Not having an installer opens the way to portable applications. If the program has everything in a directory, then this can simply be copied to a USB stick and be run on any system. This may of course not make sense for your particular kind of app, but that is for you to decide.
I'm not sure that the issue about corrupted settings is really important here. If settings are corrupted (why?) - how is the application to know what to do about it? OTOH the installer can of course also be written to not blindly overwrite any old settings. It all depends...
Edit: You write in your comment:
Even portable apps require certain configuration/settings, Isn't it better to have the main app check that settings are valid/exist on each startup, and only prompt the user when needed.
and again, it really depends on your needs. There are different types of configuration settings or preferences, and you have to decide individually:
Per-user configuration settings will be missing if the application is run for the first time by the current user. It can be helpful to show a message that it is missing, and how to create it. For example in FlameRobin (a database administration program for Firebird) we have a message that is shown when no registered servers and databases are found on program startup, and how to register them.
Per-user settings for UI behaviour will also be missing, but there are default values for them. The user will get the default behaviour of the application, and can later change things in the option dialog. Since it is best to minimize the number of such settings, and since the defaults should be what most users expect or what works best in the general case, there is also no need to bother the user at program startup.
Some configuration may be not per-user, but per-program. This is generally stored in a location where standard users have no write access, so checking for this and prompt the user to enter it is not really helpful. What could be done is to start an external program, asking the standard user for the account with sufficient privileges and its password.
Going with a separate installer is the "better" way from my point of view. Making an application self-installing does not only add additional workload to the application itself, it also "works around" any installer system of the underlying operating system (like MSI on windows).
And if the application corrupt its settings over time it's broken and need to be fixed. How should corrupt settings be handled by the self-installer? Just overwrite it with the defaults? Users will get annoyed by that too, so having them to run a separate installer and choosing a "repair" option makes this at least more transparent.
I would recommend a separate installer that can do the following:
Install a new installation
Repair an existing installation
Remove an existing installation
The reason I recommend these options is because that is what I have come to expect for installers in Windows environments.
The reasons I recommend separating installation and application logic into two different applications area:
There may be conflicts between dependencies used used by the installer and application.
I want to be sure my team don't inadvertently use classes in the dependencies from the installer framework when developing the application.
Thanks for your feedback. I'm starting to think something along these lines would be a good compromise approach:
Choose the self installer approach by creating an installer component (class library) that is referenced by the main application.
This component is a core part of the application and is responsible for ensuring all configuration/settings exist and are valid.
The main app. executable, on each run, asks this component to check existance/validity of settings, and only prompt the user when required. This could be easily done in a user friendly manner by grouping all setting issues and presenting them in a single GUI (avoids a sequence of annoying dialogues).
For OS integration, the installer component (in the case of Windows) ensures an entry is added to the "Add Remove Programs" list for the application, as well as any other OS required conventions.
Within the application the standard options/settings screen is also provided by the installer component. This avoids duplicating settings management code.
I've asked this question because I've met many non-technical users who ask why they cannot simply copy an application from one computer to another, they can do this with their data (eg photos, documents etc). It's an extremely valid question, in particular for GUI oriented desktop applications.
Separate installers are certainly "the way it's been done" on Windows for many years. For drivers/system components, obviously they are often a necessity. But for desktop GUI style applications I don't believe they are the best in terms of simplicity and realiability for the user/customer.