yq is a lightweight and portable command-line YAML, JSON and XML processor. yq uses jq like syntax but works with yaml files as well as json, xml, properties, csv and tsv. It doesn't yet support everything jq does - but it does support the most common operations and functions, and more is being added continuously. yq is written in go - so you can download a dependency free binary for your platform and you are good to go! If you prefer there are a variety of package managers that can be used as well as Docker and Podman, all listed below.

# decode kubernetes secret as yaml
kubectl get secret some_secret -o yaml | yq '(.data)=(.data|map_values(@base64d))'

# update key-value pair inside a nested yaml
some_variable=5 yq -i '.spec.template.spec.containers[].env += {"name": "key", "value": env(some_variable)}' deployment-some-service.yaml
  yq [flags]
  yq [command]


# yq defaults to 'eval' command if no command is specified. See "yq eval --help" for more examples.

# read the "stuff" node from "myfile.yml"
yq '.stuff' < myfile.yml

# update myfile.yml in place
yq -i '.stuff = "foo"' myfile.yml

# print contents of sample.json as idiomatic YAML
yq -P sample.json

Available Commands:
  completion       Generate the autocompletion script for the specified shell
  eval             (default) Apply the expression to each document in each yaml file in sequence
  eval-all         Loads _all_ yaml documents of _all_ yaml files and runs expression once
  help             Help about any command
  shell-completion Generate completion script

  -C, --colors                        force print with colors
  -e, --exit-status                   set exit status if there are no matches or null or false is returned
      --expression string             forcibly set the expression argument. Useful when yq argument detection thinks your expression is a file.
      --from-file string              Load expression from specified file.
  -f, --front-matter string           (extract|process) first input as yaml front-matter. Extract will pull out the yaml content, process will run the expression against the yaml content, leaving the remaining data intact
      --header-preprocess             Slurp any header comments and separators before processing expression. (default true)
  -h, --help                          help for yq
  -I, --indent int                    sets indent level for output (default 2)
  -i, --inplace                       update the file inplace of first file given.
  -p, --input-format string           [yaml|y|props|p|xml|x] parse format for input. Note that json is a subset of yaml. (default "yaml")
  -M, --no-colors                     force print with no colors
  -N, --no-doc                        Don't print document separators (---)
  -n, --null-input                    Don't read input, simply evaluate the expression given. Useful for creating docs from scratch.
  -o, --output-format string          [yaml|y|json|j|props|p|xml|x] output format type. (default "yaml")
  -P, --prettyPrint                   pretty print, shorthand for '... style = ""'
  -s, --split-exp string              print each result (or doc) into a file named (exp). [exp] argument must return a string. You can use $index in the expression as the result counter.
      --split-exp-file string         Use a file to specify the split-exp expression.
  -r, --unwrapScalar                  unwrap scalar, print the value with no quotes, colors or comments (default true)
  -v, --verbose                       verbose mode
  -V, --version                       Print version information and quit
      --xml-attribute-prefix string   prefix for xml attributes (default "+")
      --xml-content-name string       name for xml content (if no attribute name is present). (default "+content")
      --xml-keep-namespace            enables keeping namespace after parsing attributes (default true)
      --xml-raw-token                 enables using RawToken method instead Token. Commonly disables namespace translations. See https://pkg.go.dev/encoding/xml#Decoder.RawToken for details. (default true)
      --xml-strict-mode               enables strict parsing of XML. See https://pkg.go.dev/encoding/xml for more details.

Use "yq [command] --help" for more information about a command.