datad is a system service that periodically collects data about its host and reports the data to a remote service. datad runs as a systemd service unit and will collect data on a schedule determined by configuration values.
Data is collected through "agents". A collection agent is an executable file found in the directory /usr/libexec/datad-agents/. When datad begins a collection, it executes each agent. An agent's standard output is piped into a buffer by datad. This buffer is then scanned for any redactions listed in the configuration structure. Finally, the buffer is added to a map of agent output results before being submitted to the collection service.
datad can be configured to submit collected data to a collection service. This is done by specifying a base URL in the [submission] section of /etc/datad/config.toml. If the submission server requires authentication, the keys auth-type, username, password, cert-file, and key-file may be required, depending on the configuration of the submission server. The agent output is aggregated into a table mapping an agent name to the output buffer. This data is then compressed and transmitted via an HTTP POST request to the submission server.
datad reads its main configuration from the file /etc/datad/config.toml. Additional configuration files may be added to /etc/datad/config.d, and are loaded in lexicographic order into the main configuration structure at runtime. Thus, override a value in a later file will replace any values specified previously.
Access to a file may be denied by adding an entry to the denylist array.
denylist = [
"/etc/pki/.*",
]Entries in the files key are regular expressions matching a file's absolute path. If a file is matched by an expression in this array, it is omitted entirely from any collected data.
File content may be redacted on a line-by-line basis by adding an entry to the redactions array.
redactions = [
".*lan$",
]When data is collected, output is searched, line by line, using the provided regular expression pattern. Any line found to match the pattern is omitted.