# NAME mccs - Fully-featured static file server. # SYNOPSIS $ mccs [OPTS] [DIR] # serve current working directory over HTTP, port 5000 $ mccs # serve a directory on port 80 using Starman $ mccs -s Starman --listen :80 /some/directory # DESCRIPTION `mccs` is an HTTP static file server that can be used as a standalone application, or as a [Plack](https://metacpan.org/pod/Plack) component. ## FEATURES - Automatic, durable compression of files based on client support. - Automatic minification of CSS and JavaScript files. - Content negotiation including proper setting and handling of cache-related headers. - Optional virtual-hosts mode for serving multiple websites. - Flexible deployment with support for various HTTP servers, FastCGI servers, UNIX domain sockets, and more. `mccs` aims for reducing CPU load by retaining minified and compressed representations of files until they are no longer valid. It does not recompress on every request. For information on how to use `mccs` as a library or embedded in [Plack](https://metacpan.org/pod/Plack) applications, see [Plack::App::MCCS](https://metacpan.org/pod/Plack%3A%3AApp%3A%3AMCCS) and [Plack::Middleware::MCCS](https://metacpan.org/pod/Plack%3A%3AMiddleware%3A%3AMCCS). # ARGUMENTS DIR The directory to serve files from. Defaults to the current working directory. # OPTIONS - --minify/--nominify Whether to minify CSS/JS files automatically. By default, `--minify` is on. - --compress/--nocompress Whether to compress files automatically. By default, `--compress` is on. - --etag/--noetag Whether to calculate ETag values for files and support `If-None-Match` headers. By default, `--etag` is on. - --vhost-mode Enables virtual hosts mode, which allows serving multiple websites based on the HTTP Host header (HTTP/1.0 requests will not be supported in this mode). When enabled, the directory being served must contain subdirectories named after each host/domain to be served. - --ignore-file Accepts a path to a file in the [Gitignore](https://git-scm.com/docs/gitignore) format. Any request that matches a rule in this file will result in a 404 Not Found response. Defaults to .mccsignore in the root directory. In vhost mode, every host can have its own ignore file, and there can also one global file for all hosts. Both the host-specific file and the global file will be used if they exist. - -s, --server, the `PLACK_SERVER` environment variable Selects a specific server implementation to run on. When provided, the `-s` or `--server` flag will be preferred over the environment variable. If no option is given, `mccs` will try to detect the _best_ server implementation based on the environment variables as well as modules loaded by your application in `%INC`. See [Plack::Loader](https://metacpan.org/pod/Plack%3A%3ALoader) for details. - -S, --socket Listens on a UNIX domain socket path. Defaults to undef. This option is only valid for servers which support UNIX sockets. - -l, --listen Listens on one or more addresses, whether "HOST:PORT", ":PORT", or "PATH" (without colons). You may use this option multiple times to listen on multiple addresses, but the server will decide whether it supports multiple interfaces. - -D, --daemonize Makes the process run in the background. It's up to the backend server/handler implementation whether this option is respected or not. - --access-log Specifies the pathname of a file where the access log should be written. By default, in the development environment access logs will go to STDERR. Note that `mccs` is an extension of [plackup](https://metacpan.org/pod/plackup), and accepts all the flags and options supported by it, but not all make sense in the context of `mccs` usage. It is recommended to use an HTTP server such as [Twiggy](https://metacpan.org/pod/Twiggy) or [Starman](https://metacpan.org/pod/Starman) in a production setting. Other options that starts with "--" are passed through to the backend server. See each [Plack::Handler](https://metacpan.org/pod/Plack%3A%3AHandler) backend's documentation for more details on their available options. # HOW DOES IT WORK? When a request is accepted by the server, the following process is initiated: - 1. Discovery: `mccs` attempts to find the requested path in the root directory. If the path is not found, `404 Not Found` is returned. If the path exists but is a directory, `403 Forbidden` is returned (directory listings are currently not supported). - 2. Examination: `mccs` will try to find the content type of the file, either by its extension (relying on [Plack::MIME](https://metacpan.org/pod/Plack%3A%3AMIME) for that), or by a specific setting provided to the app by the user (will take precedence). If not found (or file has no extension), `text/plain` is assumed (which means you should give your files proper extensions if possible). `mccs` will also determine for how long to allow clients (whether browsers, proxy caches, etc.) to cache the file. By default, it will set a representation as valid for 86400 seconds (i.e. one day). However, this can be changed either by setting a different global validity interval, or by setting a specific value for certain file types. By default, `mccs` also sets the `public` option for the `Cache-Control` header, meaning caches are allowed to save responses even when authentication is performed. You can change that the same way. - 3. Minification If the content type is `text/css` or `application/javascript`, `mccs` will try to find a pre-minified version of it on disk. If found, and the version is younger than the original file, then it will be marked for serving. Otherwise, if [CSS::Minifier::XS](https://metacpan.org/pod/CSS%3A%3AMinifier%3A%3AXS) or [JavaScript::Minifier:XS](https://metacpan.org/pod/JavaScript%3A%3AMinifier%3AXS) are installed, `mccs` will minify the file, save the minified version to disk, and mark it as the version to serve. Future requests to the same file will see the minified version and not minify again. `mccs` searches for files that end with `.min.css` and `.min.js`, and that's how it creates them too. If a request comes to `style.css`, for example, then `mccs` will look for `style.min.css`, possibly creating it if not found or stale. The request path remains the same (`style.css`) though, even internally. If a request comes to `style.min.css` (which you don't really want when using `mccs`), the app will not attempt to minify it again (so you won't get things like `style.min.min.css`). If `min_cache_dir` is specified, it will do all its searching and storing of generated minified files within `$root`/`$min_cache_dir` and ignore minified files outside that directory. - 4. Compression If the client supports compressed responses (via the gzip, deflate or zstd algorithms), as noted by the `Accept-Encoding` header, `mccs` will try to find a precompressed version of the file on disk. If found, and is not stale, this version is marked for serving. Otherwise, if the appropriate compression module is installed, `mccs` will compress the file, save the compressed version to disk, and mark it as the version to serve. Future requests to the same file will see the compressed version and not compress again. `mccs` searches for files that end with the appropriate extension for the algorithm (i.e. `.gz`, `.zip`, `.zstd`), and that's how it creates them too. If a request comes to `style.css` from a client that prefers gzip responses, for example, and the file was minified in the previous step, `mccs` will look for `style.min.css.gz`, possibly creating it if not found. The request path remains the same (`style.css`) though, even internally. `mccs` honors weight values supplied in the `Accept-Encoding` header, and will serve using the highest-weighted algorithm it supports. - 5. Cache Validation If the client provided the `If-Modified-Since` header, `mccs` will determine if the file we're serving has been modified after the supplied date, and return `304 Not Modified` immediately if not. If file doesn't have the 'no-store' cache control option, and the client provided the `If-None-Match` header, `mccs` will look for a file that has the the same name as the file we're going to serve, plus an `.etag` suffix, such as `style.min.css.gz.etag`, for example. If found, and not stale, the content of this file is read and compared with the provided ETag. If the two values are equal, `mccs` will immediately return `304 Not Modified`. - 6. ETagging If an `.etag` file wasn't found in the previous step, and the file we're serving doesn't have the 'no-store' cache control option, `mccs` will create one from the file's inode, last modification date and size. Future requests to the same file will see this ETag file, so it is not created again. - 7. Headers and Cache-Control `mccs` now sets headers, especially cache control headers, as appropriate: - `Content-Encoding` is set to the compression algorithm used, if any. - `Content-Length` is set with the size of the file in bytes. - `Content-Type` is set with the MIME type of the file (if a text file, the character string is appended, e.g. `text/css; charset=UTF-8`). - `Last-Modified` is set with the last modification date of the file in HTTP date format. - `Expires` is set with the date on which cached versions should expire, as determined in stage 2, in HTTP date format. - `Cache-Control` is set with the number of seconds the representation is valid for (unless caching of the file is not allowed) and other options, as determined in stage 2. - `Etag` is set with the ETag value (if exists). - `Vary` is set with `Accept-Encoding`. - 8. Serving The selected file is served to the client. # CAVEATS AND THINGS TO CONSIDER - You can't tell `mccs` not to minify/compress a specific file type, but only disable minification/compression altogether. - Directory listings are not supported. - Caching middlewares such as [Plack::Middleware::Cache](https://metacpan.org/pod/Plack%3A%3AMiddleware%3A%3ACache) and [Plack::Middleware::Cached](https://metacpan.org/pod/Plack%3A%3AMiddleware%3A%3ACached) don't rely on Cache-Control headers (or so I understand) for their expiration values, which makes them less useful for applications that rely on [Plack::App::MCCS](https://metacpan.org/pod/Plack%3A%3AApp%3A%3AMCCS) or [Plack::Middleware::MCCS](https://metacpan.org/pod/Plack%3A%3AMiddleware%3A%3AMCCS). You'll probably be better off with an external cache like [Varnish](https://www.varnish-cache.org/) if you want a cache on your application server. Even without a server cache, your application should still appear faster for users due to browser caching (and also CPU load should be decreased). - `Range` requests are not supported. See [Plack::App::File::Range](https://metacpan.org/pod/Plack%3A%3AApp%3A%3AFile%3A%3ARange) if you need that. - The app is mounted on a directory and can't be set to only serve requests that match a certain regular expression. Use the [middleware](https://metacpan.org/pod/Plack%3A%3AMiddleware%3A%3AMCCS) for that. # DIAGNOSTICS `mccs` doesn't directly throw any exceptions, instead returning HTTP errors to the client and possibly issuing some `warn`s. The following list should help you to determine some potential problems with `MCCS`: - `"Failed compressing %s with %s: %s"` This warning is issued when `mccs` fails to compress a file with a certain algorithm. When it happens, a compressed representation will not be returned. - `"Can't open ETag file %s.etag for reading"` This warning is issued when `mccs` can't read an ETag file, probably because it does not have enough permissions. The request will still be fulfilled, but it won't have the `ETag` header. - `"Can't open ETag file %s.etag for writing"` Same as before, but when `mccs` can't write an ETag file. - `403 Forbidden` is returned for files that exist If a request for a certain file results in a `403 Forbidden` error, it probably means `mccs` has no read permissions for that file. # CONFIGURATION AND ENVIRONMENT `mccs` requires no configuration files or environment variables. # REQUIREMENTS `mccs` **requires** the following dependencies: - [Perl 5.36+](https://www.perl.org/) - [HTTP::Date](https://metacpan.org/pod/HTTP%3A%3ADate) - [Plack](https://metacpan.org/pod/Plack) `mccs` will use the following CPAN modules if they exist: - [CSS::Minifier::XS](https://metacpan.org/pod/CSS%3A%3AMinifier%3A%3AXS) - [JavaScript::Minifier::XS](https://metacpan.org/pod/JavaScript%3A%3AMinifier%3A%3AXS) - [IO::Compress::Zstd](https://metacpan.org/pod/IO%3A%3ACompress%3A%3AZstd) The following CPAN modules are also recommended: - [Twiggy](https://metacpan.org/pod/Twiggy) for an event-loop based HTTP server. - [Starman](https://metacpan.org/pod/Starman) for a preforking HTTP server. # INCOMPATIBILITIES WITH OTHER MODULES None reported. # BUGS AND LIMITATIONS Please report any bugs or feature requests to `bug-Plack-App-MCCS@rt.cpan.org`, or through the web interface at [http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Plack-App-MCCS](http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Plack-App-MCCS). # SEE ALSO [Plack::App::MCCS](https://metacpan.org/pod/Plack%3A%3AApp%3A%3AMCCS), [Plack::Middleware::MCCS](https://metacpan.org/pod/Plack%3A%3AMiddleware%3A%3AMCCS), [Plack::Runner](https://metacpan.org/pod/Plack%3A%3ARunner), [plackup](https://metacpan.org/pod/plackup). # AUTHOR Ido Perlmuter # ACKNOWLEDGMENTS Some of this application's code is based on [Plack::App::File](https://metacpan.org/pod/Plack%3A%3AApp%3A%3AFile) by Tatsuhiko Miyagawa and [Plack::Middleware::ETag](https://metacpan.org/pod/Plack%3A%3AMiddleware%3A%3AETag) by Franck Cuny. Christian Walde contributed new features and fixes for the 1.0.0 release. # LICENSE AND COPYRIGHT Copyright (c) 2011-2023, Ido Perlmuter `ido@ido50.net`. Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.