Module Tezos_base_unix.File_descriptor_sink

An implementation of Tezos_base.Internal_event.SINK which writes the events as JSON or pretty printed into a single file-descriptor.

An URI scheme is used to describe such file descriptors:

• "file-descriptor-path" outputs to the file at the URI path
• "file-descriptor-stdout" outputs to stdout
• "file-descriptor-stderr" outputs to stderr
• "file-descriptor-syslog" outputs to a syslog facility

Available options are

• "level-at-least" the minimal log-level that the sink will output (see Tezos_event_logging.Internal_event.level).
• "section-prefix" can be given many times and defines a list of pairs "<section-prefix>:<level-threshold>" which can be used to setup more precise filters. "level-at-least=info" is understood as "section-prefix=:info" (the empty section prefix matches all sections). To exclude completely a section from the log stream that the sink will output, you can use the special level-threshold "none".

• "format" the output format used.Note that syslog output will ignore this option and use the syslog formatting. Possible values are
• "one-per-line" (the default),
• "netstring" (see The Netstring format) (both to separate JSON records),
• "pp-rfc5424" to output the events pretty-printed as text using RFC 5424
• "pp-short" to output the events pretty-printed in a shorter and more user-friendly fashion.

• "color=true" enables logs coloring. It only works on ttys and for "format=pp-short".

Options available only for "file-descriptor-path://":

• "with-pid=true" adds the current process id to the file path provided.
• "fresh=true" smashes the content of the file if it already exists instead of appending to it.
• "chmod=<INT>" sets the access-rights of the file at creation time (default is 0o600, provided umask allows it).
• "daily-logs=<INT>" sets up a rotation for log files, keeping only the last N days where N is the given parameter. It creates a file for each day and and adds the day of the year with format "yyyymmdd" to the path provided.
• "create-dirs=true" allows to create the directory where the log files are stored and all its parents recursively if they don't exist.

Option available only for "file-descriptor-syslog://":

• "facility=<facility>" is the targeted syslog output. User is the default value if no value is provided. See RFC 3164 for more information. The possible values are defined in module Syslog.

Examples:

• export TEZOS_EVENTS_CONFIG="file-descriptor-path:///the/path/to/write.log?format=one-per-line&section-prefix=p2p.maintenance:none&with-pid=true&chmod=0o640": By default all executables will write all log events of level at least Info to a file "/the/path/to/write-XXXX.log" where "XXXX" is the process ID, the file will be also readable by the user's group (0o640). The maintenance module will be excluded from the stream.
• export TEZOS_EVENTS_CONFIG="file-descriptor-path:///the/path/to/write.log?section-prefix=rpc:debug&section-prefix=validator:debug&section-prefix=:none": Write only sections validator and rpc at debug level but exclude all other sections from the stream.
• export TEZOS_EVENTS_CONFIG="file-descriptor-path:///the/path/to/write.log?format=one-per-line&level-at-least=notice&with-pid=true&chmod=0o640": Executables will write all log events of level at least Notice to a file "/the/path/to/write-XXXX.log" where "XXXX" is the process ID, the file will be also readable by the user's group (0o640).
• "export TEZOS_EVENTS_CONFIG=file-descriptor-stderr://?format=netstring" Executables will write to stderr.
• export TEZOS_EVENTS_CONFIG="file-descriptor-path:///dev/fd/4?format=netstring" Executables will write to the 4 file-descriptor likely opened by a parent monitoring process (non-standard feature available on mainstream UNIX hosts, e.g. Linux and MacOSX).

• export TEZOS_EVENT_HOSTNAME="hostname" The hostname will be used in the JSON representation of the event. By default, it is the hostname given by Unix.gethostname ().
• "export TEZOS_EVENTS_CONFIG=file-descriptor-path:///tmp/node.log?daily-logs=5&section-prefix=:info" sets up log files with a rotation of 5 days and verbosity level info for all logs. Files will be named node-19700101.log in an example of a file produced in 1970, January, the 1st.