Modifying array of key value in JSON jq
It is enough to assign to the path, if you are using |=, e.g.
jq ' (.taskDefinition.containerDefinitions[0].environment[] | select(.name=="DB_USERNAME") | .value) |= "new"' infile.jsonOutput:
{ "taskDefinition": { "containerDefinitions": [ { "name": "web", "image": "my-image", "environment": [ { "name": "DB_HOST", "value": "localhost" }, { "name": "DB_USERNAME", "value": "new" } ] } ] }}
Here is a select-free solution using |=:
.taskDefinition.containerDefinitions[0].environment |= map(if .name=="DB_USERNAME" then .value = "new" else . end)Avoiding select within the expression on the LHS of |= makes the solution more robust w.r.t. the version of jq being used.
You might like to consider this alternative to using |=:
walk( if type=="object" and .name=="DB_USERNAME" then .value="new" else . end)