Jenkinsfile print parameters nicely - jenkins

Question

We have a Jenkinsfile with parameters declared as follows:
def params = [string(name: 'ENVIRONMENT', value: environment),
string(name: 'VERSION', value: version),
string(name: 'REGION', value: region)]
I'd like to echo these, for example
DEPLOYING: ENVIRONMENT=STAGING, VERSION=1.3.0, REGION=EU
However calling echo "$params" prints:
[#string(name=ENVIRONMENT,value=STAGING), #string(name=VERSION,value=1.3.0), #string(name=REGION,value=EU)]
I tried iterating the array - e.g. :
params.each { echo it } throws UnsupportedOperationException: no known implementation of class java.lang.String is using symbol ‘string’
params.each { echo it.name } throws RejectedAccessException: No such field found: field org.jenkinsci.plugins.structs.describable.UninstantiatedDescribable name
How can I print the params array nicely?
EDIT - from Matt Schuchard's response:
def params = [string(name: 'ENVIRONMENT', value: "STAGING"),
string(name: 'VERSION', value: "1.3.0"),
string(name: 'REGION', value: "EU")]
print "$params"
params.each() { param, value ->
print "Parameter: ${param}, Value: ${value}"
}
returns (i.e. Value is all null):
[#string(name=ENVIRONMENT,value=STAGING), #string(name=VERSION,value=1.3.0), #string(name=REGION,value=EU)]
Parameter: #string(name=ENVIRONMENT,value=STAGING), Value: null
Parameter: #string(name=VERSION,value=1.3.0), Value: null
Parameter: #string(name=REGION,value=EU), Value: null

Answer 1

You can use a Groovy map iterator lambda method (such as each) to iterate over the params map. An example follows:
params.each() { param, value ->
print "Parameter: ${param}, Value: ${value}"
}
If you decide to use this directly inside a pipeline block, then this will need to be placed inside a script block when using declarative DSL.

Answer 2

There must be a better way but the following works
Iterating the params array:
1. Cast each parameter to a regular String
2. Extracted the value between #string( VALUE )
3. Split the key/value pairs first by comma ','
4. Then split each side of the above by equals '='
5. Concatenate the second argument
def pretty(params) {
def s = ""
params.each { param ->
def a = ("${param}" =~ /^#string\((.+)\)$/)[ 0 ][ 1 ]
def b = a.split(",")
s = s + b[0].split("=")[1] + "=" + b[1].split("=")[1] + "\n"
}
return s
}
Returns:
ENVIRONMENT=STAGING
VERSION=1.3.0
REGION=EU

Answer 3

is params goal is to parameterized the build?
if this is the case, you can use parameters directive
The parameters directive provides a list of parameters that a user
should provide when triggering the Pipeline.
The values for these
user-specified parameters are made available to Pipeline steps via the
params object.
declerative pipeline:
Declarative Pipeline supports parameters out-of-the-box, allowing the
Pipeline to accept user-specified parameters at runtime via the
parameters directive.
parameters {
string(name: 'ENVIRONMENT', defaultValue: 'STAGING', description: 'Environment to test. e.g: production/develop'),
string(name: 'VERSION', defaultValue: '1.3.0', description: 'Version to run'),
string(name: 'REGION', defaultValue: 'EU', description: 'Region')
}
scripted pipeline:
Configuring parameters with Scripted Pipeline is
done with the properties step, which can be found in the Snippet
Generator
properties([
parameters([
string(name: 'ENVIRONMENT', defaultValue: 'STAGING', description: 'Environment to test. e.g: production/develop'),
string(name: 'VERSION', defaultValue: '1.3.0', description: 'Version to run'),
string(name: 'REGION', defaultValue: 'EU', description: 'Region')
])
])
now, those parameters are accessible as members of the params variable
so, then you can simply use:
params.each() { param, value ->
print "Parameter: ${param}, Value: ${value}"
}