upsource updates the local file system from remote sources. It is designed as a lightweight provisioning system.
upsource is controlled by sourcetabs, which are text files composed of lines of the following form:
sourcetype mountpoint source [VAR=VAL]*
where mountpoint is a path in the local file system, source is a remote source, and sourcetype determines how to fetch or update from source, which is written or updated into mountpoint. Some example sourcetypes are git, svn, or s3.
The rest of the sourcetab line consists of environment variable bindings which are passed to the update method. Some environment variables have standard interpretations used by update handlers:
- OWNER specifies the owner of the tree beneath mountpoint;
- GROUP specifies the group of the tree beneath mountpoint;
- MODE specifies the file mode (an argument to chmod) of the tree beneath mountpoint;
- SSH_USER specifies the username for SSH connections used by handlers;
- SSH_KEY specifies the identity key for SSH connections used by handlers;
- ENVSOURCE specifies a file to be read into the handler
The command upsource with an argument processes either the argument (if it's a file) or the name.srctab files within it (if it's a directory.
When upsource is called without any argments, it processes the default sourcetabs of the form sourcetype.sourcetab in /etc/upsource.d/. (This file location may vary).
Sourcetab handlers are defined in the directory /usr/lib/upsource/handlers/sourcetype.upsource; they are normally shell scripts and adding a new sourcetype is as simple as adding a new (executable) file of this form.