Product Description

Apache HTTP Server

Apache HTTP Server is a web server. Apache HTTP Server is available on a large number of platforms including most Unix platforms, Windows, Mac OS X, NetWare.

It has been taken and used as the base for a number of other Web server products, including IBM HTTP Server, Oracle HTTP Server and HP HP-UX Apache-based Web Server

IBM HTTP Server

The IBM HTTP Server is a simple Web HTTP hosting server. It communicates with LDAP, supports SSL protocol and multi-threading. It's more optimized in sense of performance than Apache HTTP Server and uses java installation process that is standard across all platforms and compatible with the SUN and GNU Java VMs.

Oracle HTTP Server

Oracle HTTP Server enables additional functionality specific to Oracle based Databases and Application Servers.

HP HP-UX Apache-Based Web Server

HP HP-UX Apache-Based Web Server has combined numerous popular modules from other Open Source projects as well as providing HP value-added features just for the HP-UX platform.

JBoss Core Services Apache HTTP Server

Apache HTTP Server is used in multiple Red Hat JBoss Middleware products(starting from version 7 and onwards).

Software Pattern Summary

Platforms Supported by the Pattern

The pattern supports identification and versioning of all Apache based webservers on all major platforms - Unix, Linux and Windows.

Identification

Due to the broad nature of the products, the fact that three different products can use the same binary to provide a service, the same binary can be found in a number of different forms with different names and that the product sometimes forks a separate process that could be named the same as its parent, we have chosen to have a number of different triggers that can be used to run the product. Once the pattern is triggered, we perform some additional checks that will allow us to understand what the process is doing and which product it is representing.

Software Instance Triggers

If any of the trigger conditions below are met then execution of the pattern's body will commence.

Created types

The pattern creates SoftwareInstances with the following types:

Simple Identification Mappings

Versioning

Version information for this product can be gathered using one of three possible methods.

Active Versioning

For all active version commands we first perform a check to ensure that we have a full command path before executing a command or parsing a binary file.

We have identified two different ways to version these products, one of them for all Apache based Webservers, the other specifically for the IBM HTTP Server.

Before we execute the specific command we check the path of the command to see if it is a known IBM deployment, more information on how the check is performed can be found in the Apache HTTPD-based Webservers#Publisher and Type Identification section and the list of regular expressions we use to check the path can be found within the IBM section of it.

IBM Specific Version Command

If the path identifies that the webserver we are dealing with is an instance of IBM HTTP Server we then perform the IBM Specific version command.

Windows

The command that is executed on Windows involves performing a find for the string '\"HTTP\"' in a file called "version.signature" which can be found in the directory above the location of the HTTP binary.

Unix

The command that is executed on Unix involves performing a grep for the string 'HTTP' on a file called "version.signature" which can be found in the directory above the location of the HTTP binary.

Generic Apache Version Command

Unix

On Unix based systems we extract the version number of the HTTP server by parsing the binary that we triggered on using the strings command.

The command returns the first line within the binary file that contains the string "Apache/", as the version information for Apache is stored as "Apache/x.x.x.x" we can be confident that the first instance of this string contains a valid version number.

For instances of Oracle HTTP Server prior to Oracle 10g releases and for HP Apache-based Web Server the binary still contains the Apache information , due to the fact that Oracle HTTP Server nad HP Apache-based Web Server is simply Apache repackaged with an additional set of modules.

Windows

If the path was not identified as an IBM HTTP Server deployment then a more generic command is executed, we run the triggered process with the argument "-version".

Note: The executable is ran with quotes to get round the issue of running commands with spaces in the path under DOS/Windows CLI.

We have found that all of the approaches provides a version number up to four levels of depth, i.e. x.x.x.x.

Oracle HTTP Server Version Command

For Oracle HTTP Server from Oracle 10g onwards we get version information by executing the trigger process with the argument "-version". The versions returned are now based Oracle versioning and no longer on Apache versions

On Solaris x64 previous command may fail if 64 bit HTTP server is running. In this case pattern run command:

If On Solaris x64 no install_root is obtained, the following command is to be executed:

On Debian, Ubuntu:

Parsing of the Version Command Output

Because multiple Versioning Commands may be ran (Generic Command, and Oracle Command), we store all the results in a list, which may contain 1 to 2 elements. We then iterate through that list, and parse each result through a series of Regular Expressions, stopping when we find a match.

Regular Expressions employed to obtain Version (in the following order):

• IBM[_\s]+HTTP[_\s]+Server[/\s]+(\d+(?:\.\d+)*)

• (\d+(?:\.\d+)*)\s+Oracle-HTTP-Server

• HP Apache-based Web Server/(\d+(?:\.\d+)*)

• HP-UX_Apache-based_Web_Server/(\d+(?:\.\d+)*)

Path Versioning

If the Active Version Command does not return any version or publisher information then we attempt to parse the full command path against a regex to see if we can identify the publisher and/or version of the product.

As the pattern identifies multiple products from a single binary we have to ensure that any regex we use are specific to the actual product we are identifying, as such we use different regular expressions against the path

An additional processing technique is then used on the resulting value to normalise the version so that it is separated using periods rather than - or _.

Depending on the deployment of the product we have found that this approach provides a version number between one and four levels of depth, i.e. x through to x.x.x.x, and can sometimes include a separate build number as well.

In some cases in order to obtain version correctly, it is needed to expand the path. In this case pattern uses path_normalization function, imported from Common_function

Package Versioning

If neither the Active Command or Path regex return any version information but the pattern has established that the publisher is either 'Apache' or 'IBM', it then checks the installed packages to see if it can extract version information from one of them.

Package Regular expressions for 'Apache Foundation' publisher:

• ^httpd
• ^SUNWapch2r$
• ^SUNWapchu$
• ^SUNWapch2u$
• ^SUNWapch22r$
• ^SUNWapch22u$
• ^COVLapache
• ^apache2
• ^(?i)Apache HTTP Server
• web/server/apache-13
• web/server/apache-22

Package Regular expressions for 'IBM' publisher:

• ^IBMHTTP
• ^ISIHS
• ^IHS6\.base$
• ^(?i)IBM HTTP Server

If a single package is returned then the version number is taken from it and assigned to the Software Instance.

Where multiple packages are returned for "Apache Foundation" publisher they are checked against a pre-defined preference list and the most 'trusted' package is used to version the Software Instance. For "IBM" publisher version of the first found package is extracted.

Package preference in descending order:

1. httpd
2. SUNWapch2r
3. SUNWapchu
4. SUNWapch2u
5. COVLapache
6. apache2
7. SUNWapch22r
8. SUNWapch22u

Alternative Versioning Approach

From the information we have, we believe that the versioning techniques we are using are accurate enough to be considered the best options for the current releases; future release may need to have additional techniques added to cover unforeseen circumstances or new features.

Future Considerations

The current versioning techniques provide broad scope and good depth in the majority of circumstances, as such we do not know of any further versioning techniques that would be beneficial for this product at this time.

The versioning techniques may need to be updated in the future if more commands become available or new/different packages are used during the installation.

Publisher and Type Identification

The pattern attempts to obtain publisher information from the trigger process command line and the active version command.

Publisher from Trigger Process

The pattern parses the trigger process command line with the following regular expressions to check the publisher

Depending on the publisher information, the pattern assigns the product type:

If no publisher information is present, the pattern sets 'Apache HTTPD-based Webserver' type for the SI.

Publisher from Active Command

In addition to version information we can also retrieve the publisher from the Active Versioning Command, to do this we parse the executed command's output with a simple regex to identify whether IBM, Apache or Oracle was found in the output.

The same information is presented on both types of Operating Systems (Unix and Windows) in the same format so we can use a single regex for both of them.

Extracting list of installed modules

Pattern extracts the modules using the following commands:

• %full_process_cmd% -M
• %full_process_cmd%" -h
• %sbin_dir%/apache2ctl" -M

Application Model Produced by Software Pattern

Product Architecture

The webserver may be installed both as standalone as well as being included as a component of other business applications.

Single or multiple instances of the webserver could be running on a specific host, this is dictated by platform and configuration.

On Linux/Unix it is more common to find a forking instance of the webserver, it is started with a single httpd process, this then forks a number of children to assist in the handling of http requests.

On Windows it is more common to have a single process that manages all requests internally.

A single instance of the webserver can host more than one website at a single time using virtual hosts.

• Configuration Option

There is a configuration option for this product which allows to use default configuration file locations.

E.g. '/etc/httpd.conf' or '/etc/apache2/apache2.conf'. For Oracle HTTP Server pattern has additional place to look for httpd.conf file at path <ora_home>/conf/httpd.conf where ora_home is to be extracted frp, phocess command with  regex '^(?i)(.+\bohs\b)'

• Software Pattern Model

The pattern is triggered on all processes that match the specified regular expressions; this will result in the pattern being triggered a number of times equal to the number of Apache based webserver processes running on a single host - not ideal where the running instance has forked children.

To ensure that only a single Software Instance is created for each truly unique running instance of the webserver, a further check is then made to ensure that the pattern continues only if the process is the parent process - if it is a child process, then the pattern stops.

The added advantage of performing this check is that it ensures that the commands are only executed when we are sure that we have a unique instance - making the pattern more efficient and saving time when scanning.

Thanks to this functionality and the multi step commands, we are able to create a Deep Software Instance.
As mentioned above, a check is performed to ensure that the process is a distinct webserver parent process, the additional information that is then used by the pattern to create a unique key is the arguments of the process.

When an Apache based webserver is started it either uses a default configuration or has a specific configuration set using the arguments. Using the '-f' and/or '-d' arguments you can identify the specific configuration of the webserver. The -f argument is used to identify a Config File, whereas the -d argument is used to identify the ServerRoot. When present, each argument is added as an attribute to the SI.

The Pattern also creates different Software Instances based on the information it has retrieved from the commands and/or path it queried.
The Software Instance Type is based on the returned publisher, so if 'IBM' was returned by a version command or was in the path then the Type would be set to "IBM HTTP Server", this information is also used in the key to create distinct Software Instances for each type of webserver running on a specific host.

• SI Depth

The pattern creates an Instance-based Software Instance, its key being based on hashed value of Config file attribute, obtained SI type and host key. If Config file attribute is not obtained the pattern creates grouped Software Instance. Key group is based on hashed cmd line. If arguments line is present it is also added into key group.

• Build

Build attribute is extracted from full version with help of regex:

• 
  _'-(\d+)$'_

• Server root

Server root attribute is extracted in several different ways on Windows and Unix.

• Windows

The pattern tries to extract server root from trigger' args or from its children processes using the following regex:

• 
  _'-d\s+(\"\w:.*?\"|\w:\S+)'_

If this method fails, the pattern tries to extract server root from trigger command line using regular expression:

• 
  _'(?i)^(\w:.*)\\bin\\[^\\]*\.exe$'_
  

  UNIX

The pattern tries to parse trigger' arguments using regex:

• 
  _'-d (/\S+)'_

Should this method fail and active commands has succeeded, the pattern tries to extract server root from command output using regex:

• 
  _'(?i)-D HTTPD_ROOT\s*=\s*[\"\'](.*?)[\"\']'_

• Config file

Config file attribute is extracted in several different ways on Windows and Unix. If extracted path is not fully qualified, it can be combined of <SERVER_ROOT><CONFIG_FILE>.

• Windows

The pattern tries to extract config file from trigger' args or from its children processes using the following regex:

• 
  _'-f\s+(\".*?\"|\S+\.conf)'_

  If this method fails and if any of versioning commands was successful, the pattern tries to extract config file from the last obtained result:

  
  

• 
  _'(?i)-D SERVER_CONFIG_FILE\s*=\s*[\"\'](.*?)[\"\']'_

• UNIX

The pattern tries to parse trigger' arguments using regex:

• 
  _'-f (\S+)'_

If this method fails, the pattern tries to extract config file using active command output, the same way as it is managed on Windows but it parses Unix-related command results.

• Relationships Creation

• Oracle e-Business

In the case that we are dealing with the Oracle HTTP Server, the pattern works on establishing a Relationship with Oracle E-Business Suite.

While the pattern doesn't actually model a Relationship with Oracle E-Business Suite, it creates the grounds on which the Relationship is based, by modeling the ebs_sid attribute.

This attribute is added to the Web Server SI, and represents the Database SID that E-Business Suite is working with.

In order to obtain it, the pattern extracts the contents of the -f Config File, and parses its content through a Regular Expression.

Regular Expression employed to extract Database SID: (?i)DocumentRoot *.+portal[/\\](.+)_

The ebs_sid attribute is going to be looked for by the Oracle E-Business Suite Pattern, in order to model a Relationship with the Web Server.

• Website SoftwareComponents

Current ADDM model allows to see all the websites configured within an Apache Server instance. This functionality is delegated to Apache extended pattern.

• Associate processes

The pattern identifies all the child processes of the trigger process that created the SI and relates them to the SI via an associate relationship.

• Subject Matter Expertise

SME feedback would be appreciated if it could further improve Pattern accuracy and scope for identification and versioning of the products.

• Testing

This pattern has been tested against installations of all possible product types that can be created across multiple platforms, additional tests were performed against record data for other webservers to ensure that erroneous Software Instances were not created.

• Open Issues

There are no known open issues with this pattern.