Bruce supports conditional execution and other specialized actions through the use of sub-commands within operator definitions. These sub-commands modify the behavior of the main operator.
The following sub-commands allow you to control whether an operator runs based on the output of an external command:
onlyIf: Executes an external command. The operator will only run if the command’s output is a non-empty string (considered “true”). An empty string output is considered “false,” and the operator will be skipped.notIf: Executes an external command. The operator will not run if the command’s output is a non-empty string (considered “true”). An empty string output is considered “false,” and the operator will run.exitIf: Executes an external command. If the command’s output is a non-empty string (considered “true”), the entire Bruce run will immediately terminate. An empty string output is considered “false,” and the Bruce run will continue normally.Important Considerations for Conditionals:
onlyIf, notIf, and exitIf are external programs or scripts that Bruce executes. Ensure these commands are available in the environment where Bruce runs.The following examples demonstrate correct usage of conditional sub-commands with commands that produce output:
- copy: s3://somebucket/somefile.bin
dest: /usr/bin/somefile
perm: 0775
onlyIf: /usr/bin/ls /usr/bin/somefile
- cmd: /my/script.sh
onlyIf: /my/check_script.sh # Run /my/script.sh only if /my/check_script.sh outputs something
- sleep:
seconds: 60
notIf: ping -c 3 [google.com](https://www.google.com/search?q=google.com) # Don't sleep if [google.com](https://www.google.com/search?q=google.com) is reachable (ping returns output)
- cmd: /another/script.sh
exitIf: grep -q "ERROR" /path/to/logfile # exit if ERROR is found in the log file.