From the documentation at https://mikefarah.gitbook.io/yq:
yq is a a lightweight and portable command-line YAML processor. yq uses jq-like syntax but works with yaml files as well as json.
load("@yq.bzl", "yq")# Remove fields
yq(
name = "safe-config",
srcs = ["config.yaml"],
expression = "del(.credentials)",
)# Merge two yaml documents
yq(
name = "ab",
srcs = [
"a.yaml",
"b.yaml",
],
expression = ". as $item ireduce ({}; . * $item )",
)# Split a yaml file into several files
yq(
name = "split",
srcs = ["multidoc.yaml"],
outs = [
"first.yml",
"second.yml",
],
args = [
"-s '.a'", # Split expression
"--no-doc", # Exclude document separator --
],
)# Convert a yaml file to json
yq(
name = "convert-to-json",
srcs = ["foo.yaml"],
args = ["-o=json"],
outs = ["foo.json"],
)# Convert a json file to yaml
yq(
name = "convert-to-yaml",
srcs = ["bar.json"],
args = ["-P"],
outs = ["bar.yaml"],
)# Call yq in a genrule
genrule(
name = "generate",
srcs = ["farm.yaml"],
outs = ["genrule_output.yaml"],
cmd = "$(YQ_BIN) '.moo = \"cow\"' $(location farm.yaml) > $@",
toolchains = ["@yq_toolchains//:resolved_toolchain"],
)# With --stamp, causes properties to be replaced by version control info.
yq(
name = "stamped",
srcs = ["package.yaml"],
expression = "|".join([
"load(strenv(STAMP)) as $stamp",
# Provide a default using the "alternative operator" in case $stamp is empty dict.
".version = ($stamp.BUILD_EMBED_LABEL // "<unstamped>")",
]),
)