14.3. CVS Administrator ReferenceThis section provides details on creating and configuring repositories and performing other CVS administrative tasks. A single computer can run multiple copies of the CVS server, and each server can serve multiple repositories. 14.3.1. Creating a RepositorySelect a directory that will contain the repository files (/usr/local/cvsrep is used in the following examples). Use the init command to initialize the repository. Either set the $CVSROOT environment variable first: user@localhost$ export CVSROOT=/usr/local/cvsrep user@localhost$ cvs init or use the -d option to specify the repository location: user@localhost$ cvs -d /usr/local/cvsrep init For information on importing code, see Section 14.4, "CVS User Reference", especially Section 14.4.7.11, "import" and Section 14.4.7.1, "add" sections. 14.3.1.1. Setting up the password serverIf you want users to access the repository from other computers, then configure the pserver by doing the following as root:
14.3.2. Security IssuesThe following are security issues that need to be considered when working with CVS:
14.3.3. Repository StructureThe CVS repository is implemented as a normal directory with special contents. This section describes the contents of the repository directory. 14.3.3.1. The CVSROOT directoryThe CVSROOT directory contains the administrative files for the repository; other directories in the repository contain the modules. The administrative files permit (and ignore) blank lines and comment lines in addition to the lines with real configuration information on them. Comment lines start with a hash mark (`#'). Some of the administrative files contain filename patterns to match file and directory names. These patterns are regular expressions like those used in GNU Emacs. Table 14-2 contains the special constructions used most often. Table 14-2. Filename Pattern Special Constructions
CVS will perform a few important expansions in the contents of the administrative files before interpreting the results. First, the typical shell syntax for referring to a home directory is ~/, which expands to the home directory of the user running CVS; and ~user expands to the home directory of the specified user. In addition, CVS provides a mechanism similar to the shell's environment variable expansion capability. Constructs such as ${variable} will be replaced by the value of the named variable. Variable names start with letters and consist entirely of letters, numbers, and underscores. Curly brackets may be omitted if the character immediately following the variable reference is not a valid variable name character. While this construct looks like a shell environment variable reference, the full environment is not available. Table 14-3 contains the built-in variables. Table 14-3. Administrative File Variables
In order to edit these files, check out the CVSROOT module from the repository, edit the files, and commit them back to the repository. You must commit the changes for them to affect CVS's behavior. Table 14-4 describes the administrative files and their functions. Table 14-4. CVSROOT Files
Since the editinfo file is obsolete, use the $EDITOR environment variable (or the -e option) to specify the editor and the verifymsg file to specify an evaluator. Each line of the taginfo file contains a filename pattern and a command line to execute when files with matching names are tagged. 14.3.3.2. The checkoutlist fileWhenever changes to files in the CVSROOT module are committed, CVS prints the message: cvs commit: Rebuilding administrative file database to inform you that the checked-out copy in the repository has been updated to reflect any changes just committed. As with any other module directory in the repository, the CVSROOT directory contains RCS (*,v) files that retain the history of the files. But to use the files, CVS needs a copy of the latest revision. So, when CVS prints this message, it is checking out the latest revisions of the administrative files. If you have added files to the CVSROOT module (such as scripts to be called via entries in the loginfo file), you will need to list them in the checkoutlist file. This makes CVS treat them the same way as it treats the standard set of CVSROOT files. Each line in this file consists of a filename and an optional error message that is displayed in case there is trouble checking out the file. 14.3.3.3. The commitinfo fileWhenever a commit is being processed, CVS consults this file to determine whether or not any precommit checking of the file is required. Each line of the file contains a directory name pattern, followed by the path of a program to invoke when files are commited in directories with matching names. Aside from the usual filename-pattern syntax, there are two special patterns:
CVS constructs the command line for the checking program by appending the full path to the directory within the repository and the list of files being committed (this means you can specify the first few command-line arguments to the program, if necessary). If the checking program exits with a nonzero status, the commit is aborted. The programs that run via this mechanism run on the server computer when a remote repository is used. Here is an example of a commitinfo file: ALL $CVSROOT/CVSROOT/commit-ALL.pl DEFAULT $CVSROOT/CVSROOT/commit-DEFAULT.pl CVSROOT$ $CVSROOT/CVSROOT/commit-CVSROOT.pl This example assumes you will create the script files in the CVSROOT module and add them to the checkoutlist file. 14.3.3.4. The config fileRepository configuration is specified in the config administrative file.
14.3.3.5. The cvsignore fileThe cvsignore administrative file contains a list of filename patterns to ignore, just like the .cvsignore files that can appear in sandboxes and user home directories. Unlike the filename patterns in other administrative files, these patterns are in sh syntax; they are not GNU Emacs-style regular expressions. There can be multiple patterns on a line, separated by whitespace (consequently, the patterns themselves cannot contain whitespace). Table 14-5 shows the most commonly used sh-style pattern constructs. Table 14-5. Filename Patterns for cvsignore
Again, diverging from the standards used by the rest of the administrative files, the cvsignore file does not support comments. 14.3.3.6. The cvswrappers fileWhile the cvsignore file allows CVS to ignore certain files, the cvswrappers file allows you to give CVS default options for commands that work with files. Lines in this file consist of a sh-style filename pattern followed by a -k (keyword substitution mode) option and/or an -m (update method) option. The legal values for -k are described in Table 14-19. The legal values for -m are COPY and MERGE. If -m COPY is specified, CVS will not attempt to merge the files. Instead, it presents the user with conflicting versions of the file, and he can choose one or the other or resolve the conflict manually. For example, to treat all files ending in .exe as binary, add this line to the file: *.exe -k b 14.3.3.7. The history fileIf this file exists, CVS inserts records of activity against the repository. This information produces displays of the cvs history command. The history file is not intended for direct reading or writing by programs other than CVS. A repository set up with cvs init automatically has a history file. 14.3.3.8. The loginfo fileThe loginfo administrative file works much like the commitinfo file and can use the special patterns ALL and DEFAULT. This file allows you to do something with commit log messages and related information. The programs called during loginfo processing receive the log message on standard input. Table 14-6 shows the three codes that can pass additional information to the called programs via command-line arguments. Table 14-6. Special loginfo Variables
If a percent sign (%) followed by the desired variable is placed after the command path, CVS inserts the corresponding information as a whitespace-separated list with one entry for each file, preceded by the repository path (as with commitinfo). There can be only one percent sign on the command line, so if you want information from more than one variable, place the variable names inside curly brackets: %{...}. In this case, each file-specific entry has one field for each variable, separated by commas. For example, the code %{sVv} expands into a list like this: /usr/local/cvsrep/hello Makefile,1.1,1.2 hello.c,1.8,1.9 It can be helpful to send email notifications each time someone commits a file to the repository. Developers can monitor this stream of notices to determine when they should pull the latest development code into their private sandboxes. For example, consider a developer doing some preparatory work in his sandbox while he awaits stabilization and addition of another developer's new library. As soon as the new library is added and committed, email notification goes out, and the waiting developer sees the code is ready to use. So, he runs cvs upd -d in the appropriate directory to pull in the new library code and then sets about integrating it with his work. It is simple to set up this kind of notification. Just add a line like this to the CVSROOT/loginfo file: DEFAULT mail -s %s developers@company.com Often, the email address is a mailing list, which has all the interested parties (developers or otherwise) on the distribution list. If you want to send messages to multiple email addresses, you can write a script to do that and have that script called via this file. Alternatively, you can use the log.pl program that comes as part of the CVS source distribution (located at /usr/local/src/cvs-1.10.8/contrib/log.pl, assuming CVS was unpacked into /usr/local/src). Instructions for its use are provided as comments in the file. 14.3.3.9. The modules fileThe top-level directories in a repository are called modules. In addition to these physical modules, CVS provides a mechanism to create logical modules through the modules administrative file. Here are the three kinds of logical modules:
Table 14-7 shows the options that can define modules. Table 14-7. Module Options
Alias modules provide alternative names for other modules or shortcuts for referring to collections or subdirectories of other modules. Alias module definitions function like macro definitions in that they cause commands to run as if the expanded list of modules and directories was on the command line. Alias modules do not cause the modules of their definition to be grouped together under the alias name (use ampersand modules for that). For example, the definition: h -a hello makes the name h a synonym for the hello module. This definition: project -a library client server allows you to check out all three modules of the project as a unit. If an entry in the definition of an alias module is preceded by an exclamation point (!), then the named directory is excluded from the module. Regular modules allow you to create modules that are subsets of other modules. For example, the definition: header library library.h creates a module that just contains the header file from the library module. Ampersand modules are true logical modules. There are no top-level directories for them in the repository, but you can check them out to sandboxes, and directories with their names will then appear. The modules listed in the definition are below that directory. For example: project &library &client &server is almost the same as the alias module example given earlier, except that the submodules are checked out inside a subdirectory named project. In this file, long definitions may be split across multiple lines by terminating all but the last line with backslashes (\). 14.3.3.10. The notify fileThis file is used in conjunction with the watch command. When notifications are appropriate, this file is consulted to determine how to do the notification. Each line of the notify file contains a filename pattern and a command line. CVS's notification mechanism uses the command line specified to perform notifications for files having names that match the corresponding pattern. There is a single special-purpose variable, %s, that can appear in the command specification. When the command is executed, the name of the user to notify replaces the variable name. If the users administrative file exists, the user names are looked up there, and the resulting values are used for %s instead. This allows emails to be sent to accounts other than those on the local machine. Details are sent to the notification program via standard input. Typical usage of this feature is the single entry: ALL mail %s -s "CVS notification" In fact, this entry is present in the default notify file created when you run cvs init to create a repository (although it is initially commented out). 14.3.3.11. The passwd fileIf you access the repository via a pserver repository locator (see Section 14.4.1, "Repository Locators"), then CVS can have its own private authentication information, separate from the system's user database. This information is stored in the CVSROOT/passwd administrative file. This feature provides anonymous CVS access over the Internet. By creating an entry for a public user (usually anoncvs or anonymous), the pserver can be used by many people sharing the public account. If you don't want to create a system user with the same name as the public user, or if you have such a user but it has a different purpose, you can employ a user alias to map it to something else: anonymous:TY7QWpLw8bvus:cvsnoname Then, make sure you create the cvsnoname user on the system. You can use /bin/false as the login shell and the repository's root directory as the home directory for the user. To restrict the public user to read-only access, list it in the CVSROOT/readers administrative file. Additionally, CVS's private user database is useful even if you don't want to set up anonymous CVS access. You can restrict access to a subset of the system's users, provide remote access to users who don't have general system access, or prevent a user's normal system password from being transmitted in the clear over the network (see Section 14.3.2, "Security Issues"). There is no cvs passwd command for setting CVS-specific passwords (located in the repository file CVSROOT/passwd). CVS-specific user and password management are manual tasks. 14.3.3.12. The rcsinfo fileCVS consults this file when doing a commit or import to determine the log message editor template. Each entry in the file consists of a filename pattern and the name of the file to use as the template for module directories with matching names. The ALL and DEFAULT special patterns apply to this file. 14.3.3.14. The taginfo fileCVS consults this file whenever the tag or rtag commands are used. Entries in this file are filename patterns and program specifications. The ALL special pattern applies to this file. The taginfo file is called with the tag, the operation being performed, the module directory name (relative to the repository root), and the filename and revision number for each affected file. The valid operations are: add (for tag), del (for tag -d), and mov (for tag -F). If the taginfo program returns a nonzero status, the tag or rtag command that caused its execution is aborted. 14.3.3.15. The users fileIf this file exists, it is consulted during processing of the notify administrative file's contents. Entries in this file consist of two colon-separated fields on a single line. The first field is the name of a user, and the second field is a value (normally the user's email address on another machine). For example: john:john@somecompany.com jane:jane@anothercompany.com 14.3.3.16. The verifymsg fileCVS consults this file to determine if log messages should be validated. If the program returns a nonzero status, the commit is aborted. The verifymsg file is called with the full path to a file containing the log message to be verified. The ALL special pattern is not supported for this file, although DEFAULT is. If more than one pattern matches, the first match is used. 14.3.3.17. The writers fileIf this file exists, users listed in it have read/write access (unless they are also listed in the readers file, in which case they have read-only access). 14.3.4. Hacking the RepositorySince the repository is a normal directory, albeit one with special contents, it is possible to cd into the directory and examine its contents and/or make changes to the files and directories there. For each file that has been added there will be a file with the same name followed by ,v in a corresponding directory in the repository. These are RCS (the format, not the program) files that contain multiple versions of the file.
14.3.4.1. Restructuring a projectRestructuring the project by moving files and directories around (and possibly renaming them) in the repository will allow the files to retain their history. The standard way to rename a file when using CVS is to rename the file in the sandbox and do a cvs remove on the old name and a cvs add on the new name. This results in the file being disconnected from its history under the new name, so sometimes it is better to do the renaming directly in the repository, although doing this while people have active sandboxes is dangerous, since the sandboxes will contain information about a file that is no longer in the repository. 14.3.4.2. Bulk importingWhen importing an entire project, all of the project's files will be added to the repository. But, if some of these files shouldn't have been added, you'll want to remove them. Doing a cvs remove will accomplish this, but copies of those files will remain in the repository's .Attic directory forever. To avoid this, you can delete the files from the repository directly before checking out sandboxes from it. 14.3.5. ImportingIf you have an existing code base, you'll want to import it into CVS in a way that preserves the most historical information. This section provides instructions for importing projects into CVS from code snapshots or other version control systems. All of these, except the code snapshot import procedure, are based upon conversion to RCS files, followed by placing the RCS files in the proper location in the CVS repository. 14.3.5.1. Importing code snapshotsIf you have maintained project history archives manually by taking periodic snapshots of the code, you can import the first snapshot, tag it with the date or version number, and then successively overlay the updated files from later archives. Each set can then be committed and tagged in order to bootstrap a repository that maintains the prior history. For example, first unpack the distributions (this assumes they unpack to directories containing the version numbers): user@localhost$ tar xvzf foo-1.0.tar.gz user@localhost$ tar xvzf foo-1.1.tar.gz user@localhost$ tar xvzf foo-2.0.tar.gz Next, make a copy of the first version, import it into the CVS repository, check it out to make a sandbox (since importing doesn't convert the source directory into a sandbox), and use cvs tag to give it a symbolic name reflecting the project version: user@localhost$ mkdir foo user@localhost$ cp -R -p foo-1.0/* foo user@localhost$ cd foo user@localhost$ cvs import -m 'Imported version 1.0' foo vendor start user@localhost$ cd .. user@localhost$ mv foo foo.bak user@localhost$ cvs checkout foo user@localhost$ cd foo user@localhost$ cvs tag foo-1_0 user@localhost$ cd .. Now, apply the differences between version 1.0 and 1.1 to the sandbox, commit the changes, and create a tag: user@localhost$ diff -Naur foo-1.0 foo-1.1 | (cd foo; patch -Np1) user@localhost$ cd foo user@localhost$ cvs commit -m 'Imported version 1.1' user@localhost$ cvs tag foo-1_1 user@localhost$ cd .. Now, apply the differences between version 1.1 and 2.0 to the sandbox, commit the changes, and create a tag: user@localhost$ diff -Naur foo-1.1 foo-2.0 | (cd foo; patch -Np1) user@localhost$ cd foo user@localhost$ cvs commit -m 'Imported version 2.0' user@localhost$ cvs tag foo-2_0 Now, you can use the log command to view the history of the files, browse past versions of the files, and continue development under version control. 14.3.5.2. Importing from RCSIf you are migrating from RCS to CVS, following these instructions will result in a usable CVS repository. This procedure involves direct modification of the CVS repository, so it should be undertaken with caution. Before beginning, make sure none of the files to be imported into CVS are locked by RCS. Then, create a new CVS repository and module (or a new module within an existing repository). Next, create directories in the CVS repository to mirror the project's directory structure. Finally, copy all the version files (,v) from the project (which may be in RCS subdirectories) into the appropriate directories in the repository (without RCS subdirectories). For example, first move aside the directory under RCS control, create an empty directory to build the new CVS structure, import the directory, and then check it out to make a sandbox: user@localhost$ mv foo foo-rcs user@localhost$ mkdir foo user@localhost$ cd foo user@localhost$ cvs import -m 'New empty project' foo vendor start user@localhost$ cd .. user@localhost$ mv foo foo.bak user@localhost$ cvs checkout foo Next, make directories and add them to the repository to match the structure in the RCS project: user@localhost$ cd foo user@localhost$ mkdir dir user@localhost$ cvs add dir user@localhost$ cd .. Now, copy the ,v files from the RCS project into the repository for the CVS project: user@localhost$ cp -p foo-rcs/*,v $CVSROOT/foo user@localhost$ cp -p foo-rcs/dir/*,v $CVSROOT/foo/dir Finally, issue the cvs update command in the sandbox directory to bring in the latest versions of all the files: user@localhost$ cd foo user@localhost$ cvs upd 14.3.5.3. Importing from SCCSTo import from SCCS, use the sccs2rcs script located in the contrib directory of the CVS distribution to convert the files to RCS format, and then follow the preceding RCS procedure. You must have both CVS and SCCS installed for this to work. The script's comments contain additional instructions. 14.3.5.4. Importing from PVCSTo import from PVCS, use the pvcs_to_rcs script located in the contrib directory of the CVS distribution to convert the files to RCS format, and then follow the previous RCS procedure. You must have both CVS and PVCS installed for this to work. The script's comments contain additional instructions. 14.3.6. Using an Interim Shared SandboxSometimes projects will develop unintended environmental dependencies over time, especially when there is no pressure for the code to be relocatable. A project developed outside version control may even be initially developed in place (at its intended installation location). While these practices are not recommended, they do occur in real-world situations; CVS can be helpful in improving the situation, by encouraging relocatability from the beginning of a project. The default mode of operation for CVS is multiple independent sandboxes, all coordinated with a central shared repository. Code that runs in this environment is necessarily (at least partially) relocatable. So, using CVS from the beginning of a project helps ensure flexibility. However, if a project is already well underway, an interim approach can be used. For example, you could convert the development area to a single shared sandbox by importing the code into CVS and checking it back out again: user@localhost$ cd /usr/local/bar user@localhost$ cvs import bar vendor start user@localhost$ cd .. user@localhost$ mv bar bar.bak user@localhost$ cvs checkout bar Chances are good that this approach is too aggressive and will check in more files than absolutely necessary. You can either go back and hack the repository to remove the files that shouldn't be there or just issue the cvs remove command to delete them as you discover them. In addition, there will probably be some binary files in the sandbox that were imported as text files. Wherever you see a binary file that needs to remain in the repository, you should issue the command cvs admin -kb file, then make a fresh copy from the project backup. Finally, issue the command cvs commit file to commit the fixed file back to the repository. Having version control in place before making flexibility enhancements is a good idea, since it makes it easier to find (and possibly reverse) changes that cause trouble. The repository locator (see Section 14.4.1, "Repository Locators") is specified via the -d option or the $CVSROOT environment variable. It is stored in the various sandbox CVS/root files. If you are using the password server (pserver), the user ID of the person checking out the sandbox will be remembered. If more than one person is working with a particular sandbox, they will have to share an account for CVS access. One way to do this is to have a neutral user account, with a password known by everyone with CVS access. Everyone can then issue the cvs login command with the same user ID and password and have access to the repository. Once you are no longer using a shared sandbox, this workaround won't be necessary. However, during the time you are using a shared sandbox, it is important that the developers type their real user IDs into their log messages, since all the changes will appear to be made by the common user. 14.3.7. Global Server OptionThe server has one global option: --allow-root=rootdir. This option is used to tell the CVS server to accept and process requests for the specified repository. 14.3.8. Administrator CommandsTable 14-8 lists the commands that CVS administrators can use to manage their repositories. Table 14-8. Administrator Commands
14.3.8.1. adminadmin [ -b[rev] ] [ -cstring ] [ -kkflag ] [ -l[rev] ] [ -L ] [ -mrev:msg ] [ -nname[:[rev]] ] [ -Nname[:[rev]] ] [ -orange ] [ -q ] [ -sstate[:rev] [ -t[file] ] [ -t-string ] [ -u[rev] ] [ -U ] [ files ... ] The admin is used to perform administrative functions. If a cvsadmin user group exists, then only those users in that group will be able to run admin with options other than -k. Additional options that may be used with the admin command are listed in Table 14-9. Table 14-9. admin Options
If the revision specified for -l is a branch, the latest revision on that branch will be used. If no revision is given, the latest revision on the default branch is used. If the name given for -n is already in use, an error is generated. You can use -N to move a tag (change the revision associated with the tag); however, you should usually use cvs tag or cvs rtag instead. The -o option is very dangerous and results in a permanent loss of information from the repository. Use it with extreme caution and only after careful consideration. See Table 14-10 for the various ways to specify ranges. There must not be any branches or locks on the revisions to be removed. Beware of interactions between this command and symbolic names. If no file is specified to the -t option, CVS reads from standard input until it reaches the end of the file or a period on a line by itself. The determination of the target revision for the -u option is the same as for -l. Table 14-10. Range Formats
The options in Table 14-11 are present in CVS for historical reasons and should not be used (using these options may corrupt the repository). Table 14-11. Obsolete admin Options
14.3.8.2. initinit Initializes the repository. Use the global -d option to specify the repository's directory if $CVSROOT isn't set appropriately. The newly initialized repository will contain a CVSROOT module, but nothing else. Once the repository is initialized, use other CVS commands to add files to it or to check out the CVSROOT module to make changes to the administrative files. 14.3.8.3. pserverpserver Operate as a server, providing access to the repositories specified before the command with the --allow-root option. This command is used in the inetd.conf file, not on the command line. Another global option frequently used with this command is -T (see Table 14-1). Copyright © 2001 O'Reilly & Associates. All rights reserved. |
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