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Cromwell Hosts

Register Cromwell servers under short names and select them by name.

  • Type the URL once

    Register a server, then refer to it as prod or local

  • Switch per command

    --host prod works on every command, and so does CROMWELL_HOST=prod

  • Know what is up

    pumbaa host check pings every registered server

Quick Start

pumbaa host add local http://localhost:8000
pumbaa host add prod https://cromwell.example.com

pumbaa --host prod workflow query     # one command against prod
pumbaa host use prod                  # or make it the default

The first host registered becomes the default, so a single-server setup needs no further configuration.

Commands

Command Description
pumbaa host List registered hosts (same as host list)
pumbaa host add <alias> <url> Register a server; --default also makes it the default
pumbaa host use <alias> Make a registered host the default
pumbaa host remove <alias> Remove a host (the default moves to another one)
pumbaa host check [alias] Check reachability — of one host, or all of them 
$ pumbaa host list

Cromwell hosts
─────────────────────────────────────────
     ALIAS  URL
 →*  local  http://localhost:8000
     prod   https://cromwell.example.com

ℹ → in use now   * default

The two markers differ whenever --host or CROMWELL_HOST overrides the default, which is exactly when it matters.

How a host is resolved

Anywhere a host is accepted — the --host flag, the CROMWELL_HOST environment variable — the value may be an alias or a URL:

  1. A registered alias always wins.
  2. Otherwise, anything carrying a scheme, a dot, a colon or a slash is treated as a URL (localhost:8000 becomes http://localhost:8000).
  3. Anything else is a typo, and is reported as one — with the registered hosts and the nearest match:
$ pumbaa --host prd workflow query
Error: unknown host "prd" (did you mean "prod"?); registered hosts: local, prod.
Register it with `pumbaa host add prd <url>`, or pass a full URL

Aliases are bare words: letters, digits, - and _. That restriction is what keeps a reference unambiguous.

With nothing given, the default is the alias marked with *, then the single-server cromwell_host setting, then http://localhost:8000.

Where it lives

Hosts are stored in ~/.pumbaa/config.yaml:

hosts:
    local: http://localhost:8000
    prod: https://cromwell.example.com
default_host: prod

The alias also names the server in the dashboard header and in the local run history, which is keyed by host — the same workflow ID on two servers is two different runs.

See also