This PR refactors the way processes are started, watched, killed, and restarted. The routines in exec.go were a mixture of higher-level worker process management (including restart delays, PID file management, etc.) and lower-level process start and kill routines. This PR moves the higher-level logic out of exec.go and into a file called worker.go. The routines in exec.go are now purely lower-level routines that start and stop processes; they have no awareness of worker configuration or process restart management (startProcess, stopProcess, waitProcess). The functions in worker.go operate on a workerConfig data structure to start, stop and manage workers.
A workerConfig structure is created by parsing an optional configuration file that must be defined in /etc/yggdrasil/workers. This configuration file, if present when a worker is started, is loaded. The 'env' field of the configuration file is parsed as a string slice. Elements of this slice must be in the form of a "VAR=VALUE" string, and are inserted into the worker process's environment before starting. It is forbidden to set PATH or any variable beginning with YGG_ in a worker's configuration file. Any variables by these names will be omitted when starting the worker process.
A worker's environment is automatically configured with a reasonable base PATH value (/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin) and inherits values from its parent for: http_proxy, HTTP_PROXY, HTTPS_PROXY, ALL_PROXY, and NO_PROXY.
This PR refactors the way processes are started, watched, killed, and restarted. The routines in
exec.gowere a mixture of higher-level worker process management (including restart delays, PID file management, etc.) and lower-level process start and kill routines. This PR moves the higher-level logic out ofexec.goand into a file calledworker.go. The routines inexec.goare now purely lower-level routines that start and stop processes; they have no awareness of worker configuration or process restart management (startProcess,stopProcess,waitProcess). The functions inworker.gooperate on aworkerConfigdata structure to start, stop and manage workers.A
workerConfigstructure is created by parsing an optional configuration file that must be defined in/etc/yggdrasil/workers. This configuration file, if present when a worker is started, is loaded. The 'env' field of the configuration file is parsed as a string slice. Elements of this slice must be in the form of a "VAR=VALUE" string, and are inserted into the worker process's environment before starting. It is forbidden to set PATH or any variable beginning with YGG_ in a worker's configuration file. Any variables by these names will be omitted when starting the worker process.A worker's environment is automatically configured with a reasonable base PATH value (
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin) and inherits values from its parent for:http_proxy,HTTP_PROXY,HTTPS_PROXY,ALL_PROXY, andNO_PROXY.