Running Flows
Overview
Note: this feature is still under active development. All features described here are subject to change.
Note: this feature supports only concord-v2 flows.
The CLI tool forces the runtime parameter value to concord-v2.
The CLI tool can run Concord flows locally:
# concord.yml
flows:
default:
- log: "Hello!"
$ concord run
Starting...
21:23:45.951 [main] Hello!
...done!
By default, concord run copies all files in the current directory into
a $PWD/target directory – similarly to Maven.
The concord run command doesn’t use a Concord Server, the flow execution is
purely local. However, if the flow uses external resources (such as
dependencies or imports) a working network connection might be required.
Supported features:
- all regular flow elements;
- dependencies;
- imports;
- secrets. See below for more details.
Features that are currently not supported:
Secrets
By default, Concord CLI uses a local file-based storage to access secrets used in flows.
For example, when running a flow like this:
# concord.yml
flows:
default:
- log: "${crypto.exportAsString('myOrg', 'mySecretString', null)}"
Concord CLI looks for a $HOME/.concord/secrets/myOrg/mySecretString file
and returns its content.
For key pair secrets Concord CLI looks for two files:
$HOME/.concord/secrets/$ORG_NAME/$SECRET_NAME(private key)$HOME/.concord/secrets/$ORG_NAME/$SECRET_NAME.pub(public key)
Note: currently, all secret values stored without encryption. Providing
a password in the crypto task arguments makes no effect.
The CLI tool also supports the crypto.decryptString method, but instead of
decrypting the provided string, the string is used as a key to look up
the actual value in a “vault” file.
The default value file is stored in the $HOME/.concord/vaults/default
directory and has very simple key-value format:
key = value
Let’s take this flow as an example:
flows:
default:
- log: "${crypto.decryptString('ZXhhbXBsZQ==')}"
When executed, it looks for the ZXhhbXBsZQ== key in the vault file and
returns the associated value.
$ cat $HOME/.concord/vaults/default
ZXhhbXBsZQ\=\= = hello!
$ concord run
Starting...
21:52:07.221 [main] hello!
...done!
Dependencies
Concord CLI supports flow dependencies.
By default, dependencies cached in $HOME/.concord/depsCache/.
For Maven dependencies Concord CLI uses Maven Central repository by default.
Imports
Concord CLI supports flow imports.
For example:
# concord.yml
imports:
- git:
url: "https://github.com/walmartlabs/concord.git"
path: "examples/hello_world"
When executed it produces:
$ concord run
Starting...
21:58:37.918 [main] Hello, Concord!
...done!
By default, Concord CLI stores a local cache of git imports in
$HOME/.concord/repoCache/$URL.