Add list-all capability to accumulo-service

[lbschanno]

Currently the accumulo-service script only supports listing information for individual services. There are times when a user will want to retrieve the PIDs for all processes managed by Accumulo.

Modify the accumulo-service script to:

• Add the service all that can be combined with the list command to list all processes.
• Add the sub-option --json to make the list command print only the name, pid, and port of each process as json. The output will always be a json array.
• Forbid the use of the service all with the start, stop, or kill command.

Closes #6507

Some examples on a running Accumulo instance:

Default output:

$ ./accumulo-service all list
Currently running gc processes (fields: process pid port):
gc_default_1 1989905 9998
Currently running manager processes (fields: process pid port):
manager_default_1 1990414 9999
Currently running monitor processes (fields: process pid port):
monitor_default_1 1989912 9995
Currently running tserver processes (fields: process pid port):
tserver_default_1 1989881 9800
Currently running compactor processes (fields: process pid port):
compactor_default_1 1989938 9600
Currently running sserver processes (fields: process pid port):
sserver_default_1 1989927 9700

Using the --json option combined with all:

$ ./accumulo-service all list --json
[
  {
    "process": "gc_default_1",
    "pid": "2001397",
    "port": "9998"
  },
  {
    "process": "manager_default_1",
    "pid": "2001906",
    "port": "9999"
  },
  {
    "process": "monitor_default_1",
    "pid": "2001399",
    "port": "9995"
  },
  {
    "process": "tserver_default_1",
    "pid": "2001374",
    "port": "9800"
  },
  {
    "process": "compactor_default_1",
    "pid": "2001434",
    "port": "9600"
  },
  {
    "process": "sserver_default_1",
    "pid": "2001426",
    "port": "9700"
  }
]

Using the --json option always results in a json array, even when there's just a single element:

$ ./accumulo-service gc list --json
[
  {
    "process": "gc_default_1",
    "pid": "2001397",
    "port": "9998"
  }
]

Using all is forbidden with any command other than list:

$ ./accumulo-service all stop
Invalid arguments: Service all can only be used with the list command

Usage: accumulo-service <service> <command>

Services:
  gc                     Accumulo garbage collector
  monitor                Accumulo monitor
  manager                Accumulo manager
  tserver                Accumulo tserver
  compactor              Accumulo compactor
  sserver                Accumulo scan server
  all                    All services (list command only)
Commands:
  start                   Starts service(s)
  stop [--all | [<name>]] Stops service(s)
  kill [--all | [<name>]] Kills service(s)
  list [--json]           List running service(s)

[dlmarion]

Seems like a good change. We have had conversations about making script / command output more CLI friendly, which is what you are trying to achieve here. I think we settled on JSON (@ctubbsii correct me here) so that the output could be parsed with jq or similar tool.

[dlmarion]

Seems like a good change. We have had conversations about making script / command output more CLI friendly, which is what you are trying to achieve here. I think we settled on JSON (@ctubbsii correct me here) so that the output could be parsed with jq or similar tool.

I was thinking of #6391

[lbschanno]

I like the idea. Do you want me to switch out -p and --parseable for --json and update the script to print out json when prompted for the list command?

[dlmarion]

I like the idea. Do you want me to switch out -p and --parseable for --json and update the script to print out json when prompted for the list command?

I think that would be good. I looked at the code earlier with this in mind and I don't think it's a heavy lift.

[lbschanno]

Done. Updated the top comment with new examples reflecting the --json option.

[dlmarion]

Done. Updated the top comment with new examples reflecting the --json option.

The json in the comment is invalid. One option is to add a leading [, trailing ], and , in between the objects, like:

[{
  "process": "gc_default_1",
  "pid": "1989905",
  "port": "9998"
},
{
  "process": "manager_default_1",
  "pid": "1990414",
  "port": "9999"
},
{
  "process": "monitor_default_1",
  "pid": "1989912",
  "port": "9995"
},
{
  "process": "tserver_default_1",
  "pid": "1989881",
  "port": "9800"
},
{
  "process": "compactor_default_1",
  "pid": "1989938",
  "port": "9600"
},
{
  "process": "sserver_default_1",
  "pid": "1989927",
  "port": "9700"
}]

I used json_verify to validate the json. You should be able to use that or jq.

[lbschanno]

Ah yes, you're right, silly of me. Fixing that now.

[lbschanno]

Fixed to output valid json. Top comment examples are updated.

[dlmarion]

I think your IDE messed with the spacing or something.

[lbschanno]

Fixed.