How to Convert YAML to JSON

// npm install js-yaml
const yaml = require('js-yaml');

const yamlString = `
apiVersion: v1
kind: ConfigMap
metadata:
  name: app-config
data:
  DATABASE_URL: postgres://localhost:5432/mydb
  CACHE_TTL: "3600"
  DEBUG: "false"
`;

// Parse YAML to JavaScript object
const data = yaml.load(yamlString);

// Convert to JSON string
const jsonString = JSON.stringify(data, null, 2);
console.log(jsonString);
/*
{
  "apiVersion": "v1",
  "kind": "ConfigMap",
  "metadata": {
    "name": "app-config"
  },
  "data": {
    "DATABASE_URL": "postgres://localhost:5432/mydb",
    "CACHE_TTL": "3600",
    "DEBUG": "false"
  }
}
*/

// Convert YAML file to JSON
const fs = require('fs');

function yamlFileToJson(yamlPath) {
  const content = fs.readFileSync(yamlPath, 'utf8');
  return JSON.stringify(yaml.load(content), null, 2);
}

// Handle multi-document YAML
function yamlToJsonMulti(yamlString) {
  const docs = yaml.loadAll(yamlString);
  return docs.map(doc => JSON.stringify(doc, null, 2));
}

# pip install pyyaml
import yaml
import json

yaml_string = """
server:
  host: localhost
  port: 8080
  ssl: true
database:
  connection_string: postgres://localhost/db
  pool_size: 10
"""

# Parse YAML to Python dict
data = yaml.safe_load(yaml_string)

# Convert to JSON string
json_string = json.dumps(data, indent=2)
print(json_string)

# Convert YAML file to JSON file
def yaml_to_json_file(yaml_path, json_path):
    with open(yaml_path, 'r') as f:
        data = yaml.safe_load(f)
    with open(json_path, 'w') as f:
        json.dump(data, f, indent=2)

# Handle multi-document YAML (---)
def yaml_to_json_multi(yaml_string):
    docs = list(yaml.safe_load_all(yaml_string))
    return [json.dumps(doc, indent=2) for doc in docs]

# Safe loading prevents arbitrary code execution
# Always use safe_load() instead of load()

# Using yq (install: brew install yq)
yq -o=json input.yaml > output.json

# Using Python one-liner
python -c "import yaml,json,sys; print(json.dumps(yaml.safe_load(sys.stdin), indent=2))" < input.yaml > output.json

# Using Ruby (built-in)
ruby -ryaml -rjson -e 'puts JSON.pretty_generate(YAML.load(ARGF))' < input.yaml > output.json

# kubectl: Get Kubernetes resources as JSON
kubectl get deployment my-app -o json > deployment.json
kubectl get pods -o json | jq '.items[].metadata.name'

# Convert all YAML files in directory
for f in *.yaml; do
  yq -o=json "$f" > "${f%.yaml}.json"
done

# Using jq with yq
yq -o=json input.yaml | jq '.metadata'

# Get deployment as JSON
kubectl get deployment nginx -o json

# Get specific field using JSONPath
kubectl get pods -o jsonpath='{.items[*].metadata.name}'

# Apply JSON manifest (both formats work)
kubectl apply -f deployment.json

# Convert local YAML to JSON for API calls
cat deployment.yaml | yq -o=json | curl -X POST \
  -H "Content-Type: application/json" \
  -d @- \
  https://kubernetes.default.svc/apis/apps/v1/deployments

# Export all resources as JSON
kubectl get all -o json > cluster-resources.json

const yaml = require('js-yaml');

// Multi-document YAML (separated by ---)
const multiDoc = `
---
name: doc1
---
name: doc2
`;

const docs = yaml.loadAll(multiDoc);
// Returns array of documents

// YAML anchors and aliases
const withAnchors = `
defaults: &defaults
  timeout: 30
  retries: 3

production:
  <<: *defaults
  timeout: 60
`;

const resolved = yaml.load(withAnchors);
// Anchors are resolved in JSON output:
// { defaults: { timeout: 30, retries: 3 },
//   production: { timeout: 60, retries: 3 } }

// YAML special values
const specialValues = `
null_value: ~
bool_yes: yes
bool_no: no
date: 2024-01-15
`;

const parsed = yaml.load(specialValues);
// { null_value: null, bool_yes: true, 
//   bool_no: false, date: 2024-01-15T00:00:00.000Z }