Groovy - Define variable where the variable name is passed by another variable - variables

Question

I want define a variable in groovy with where the variable name is passed by another variable.
Something like.
def runExtFunc(varName){
def varName // => def abc
varName = load 'someFile.groovy' // abc = load 'someFile.groovy'
varName."$varName"() // -> abc.abc() (run function defined in File)
}
[...]
runExtFunc('abc') // -> abc.abc() (Function abc defined in File)
[...]
runExtFunc('xyz') // -> xyz.xyz() (Function xyz defined in File)
[...]
Sadly def varName defines the variable varName and not abc. When I call runExtFunc twice an error occoures bacause varName is already defined.
I also tried
def runExtFunc(varName){
def "${varName}" // => def abc
[...]
"${varName}" = load 'someFile.groovy'
[...]
}
which doesn't work either.
Any suggestions?

Answer 1

This is the wrong approach. Normally you would use List, Map or Set data structures, which allow you to save a collection and access specific elements in the collection.
List allows you to hold specific values (unique or non-unique). Set allows you to hold specific values (all unique). Map allows you to have Key, Value pairs (Key must be unique) .
Read more here
groovy list,
groovy map

Answer 2

Try this (if I understand you correctly):
def dummyFunc(varName) {
new GroovyShell(this.binding).evaluate("${varName}")
}
dummyFunc('abc')
abc = "Hello there"
println abc
Prints
Hello there

Answer 3

See here
https://godless-internets.org/2020/02/14/extracting-jenkins-credentials-for-use-in-another-place/
secret_var="SECRET_VALUE_${secret_index}"
aws ssm put-parameter --name ${param_arn} --type "SecureString" --value ${!secret_var} --region us-east-2 --overwrite

Answer 4

I'm entering here a code sample we've done.
Please, feel free to comment.
http://groovy-lang.org/syntax.html
https://godless-internets.org/2020/02/14/extracting-jenkins-credentials-for-use-in-another-place/
def int fileContentReplaceDynamic(String filePathVar, String envTail = "",
String [] keysToIgnore = new String[0]){
def filePath = readFile filePathVar
def lines = filePath.readLines()
//def regex = ~/\b__\w*\b/
String regex = "__(.*?)__"
ArrayList credentialsList = new ArrayList();
ArrayList<String> keysToIgnoreList = new ArrayList<String>(Arrays.asList(keysToIgnore));
for (line in lines){
Pattern pattern = Pattern.compile(regex, Pattern.CASE_INSENSITIVE)
Matcher matcher = pattern.matcher(line)
while (matcher.find()){
String credKeyName = matcher.group().replaceAll("__","")
if ((! credentialsList.contains(credKeyName)) &&
(! keysToIgnoreList.contains(credKeyName))) {
credentialsList.add(credKeyName)
} else {
log.info("Credencial ignorada o ya incluida: ${credKeyName}")
}
}
}
if(credentialsList.size() <= 0){
log.info("No hay variables para aplicar transformada")
return 0
}
log.info("Numero de credenciales encontradas a sustituir: " + credentialsList.size())
String credentialsListString = String.join(", ", credentialsList);
log.info("Credenciales: " + credentialsListString)
def credsRequest = null
for(def credKeyName in credentialsList){
// Retrieve the values of the variables by environment tail name.
String credKeyNameByEnv = "${credKeyName}";
if ((envTail != null) && (! envTail.trim().isEmpty())) {
credKeyNameByEnv = credKeyNameByEnv + "-" + envTail.trim().toUpperCase();
}
// Now define the name of the variable we'll use
// List<org.jenkinsci.plugins.credentialsbinding.MultiBinding>
// Tip: java.lang.ClassCastException:
// org.jenkinsci.plugins.credentialsbinding.impl.BindingStep.bindings
// expects class org.jenkinsci.plugins.credentialsbinding.MultiBinding
String varName = "var_${credKeyNameByEnv}"
if (credsRequest == null) {
// Initialize
credsRequest = [string(credentialsId: "${credKeyNameByEnv}", variable: "${varName}")]
} else {
// Add element
credsRequest << string(credentialsId: "${credKeyNameByEnv}", variable: "${varName}")
}
}
int credsProcessed = 0
def passwordsRequest = null
StringBuilder sedReplacements = new StringBuilder();
// Now ask jenkins to fill in all variables with values
withCredentials(credsRequest) {
for(def credKeyName in credentialsList){
String credKeyVar = "var_${credKeyName}"
log.info("Replacing value for credential ${credKeyName} stored in ${credKeyVar}")
String credKeyValueIn = "${!credKeyVar}"
String credKeyValue = null;
if ("empty_string_value".equals(credKeyValueIn.trim())) {
credKeyValue = "";
} else {
credKeyValue = credKeyValueIn.replaceAll(/(!|"|#|#|\$|%|&|\/|\(|\)|=|\?)/, /\\$0/)
}
if (passwordsRequest == null) {
// Initialize
passwordsRequest = [[password: "${credKeyValue}" ]]
} else {
// Add element
passwordsRequest << [password: "${credKeyValue}" ]
}
sedReplacements.append("s/__${credKeyName}__/${credKeyValue}/; ")
credsProcessed++
}
}
wrap([$class: "MaskPasswordsBuildWrapper", varPasswordPairs: passwordsRequest ]){
String sedReplacementsString = sedReplacements.toString().trim();
if (sedReplacementsString.endsWith(";")) {
sedReplacementsString = sedReplacementsString.substring(0, sedReplacementsString.length() -1);
sedReplacementsString = sedReplacementsString + "g;"
}
sh """sed -i "${sedReplacementsString}" ${filePathVar}"""
}
log.info("Finaliza la transformada. Transformados: ${credsProcessed}/${credentialsList.size()} ")
if (credsProcessed != credentialsList.size()) {
log.info("Hay credenciales que no se han podido encontrar en el vault de Jenkins.")
log.info("Si estas guardando cadenas vacias en credenciales, guarda en su lugar el valor 'empty_string_value'.");
return -1
}
return 0;
}