yaml-merge

yaml-merge merges multiple YAML files into a single file. YAML files are merged in order. The first file in the list is the source, and all subsequent files are applied over it.

When ignoreMissingFiles is false (default), the step will fail if any file from inFiles does not exist.

note

Merging is performed as follows:

• Scalar values: If both documents define a scalar (string, number, boolean) at the same key, the value from the second document overrides the first.
• Mapping (object) values: If both documents define a mapping at the same key, the mappings are merged recursively.
• Sequence (array) values: If both documents define a sequence at the same key, the sequence from the second document replaces the first (no merging).
• Keys present only in one document: Keys that exist in only one document are included as-is in the result.
• Null values: If a key is set to null in the second document, it removes or overrides the value from the first document.

Configuration

Name	Type	Required	Description
inFiles	[]string	Y	Paths to a YAML files. This path is relative to the temporary workspace that Kargo provisions for use by the promotion process.
outFile	string	Y	The path to the output file. This path is relative to the temporary workspace that Kargo provisions for use by the promotion process.
ignoreMissingFiles	bool	N	When set to true, the directive will skip input files that does not exist. Defaults to false.

Output

Name	Type	Description
commitMessage	string	A description of the change(s) applied by this step. Typically, a subsequent git-commit step will reference this output and aggregate this commit message fragment with others like it to build a comprehensive commit message that describes all changes.

Examples

Common Usage

In the following example, multiple Helm values files (one "base", a second with environment-specific overrides, and a third with cluster-specific overrides) are merged into a new, single file, which is then committed to a Stage-specific branch:

vars:
- name: gitRepo
  value: https://github.com/example/repo.git
steps:
- uses: git-clone
  config:
    repoURL: ${{ vars.gitRepo }}
    checkout:
    - commit: ${{ commitFrom(vars.gitRepo).ID }}
      path: ./src
    - branch: stage/${{ ctx.stage }}
      create: true
      path: ./out
- uses: git-clear
  config:
    path: ./out
- uses: yaml-merge
  config:
    inFiles:
    - ./src/charts/my-chart/values.yaml
    - ./src/charts/qa/values.yaml
    - ./src/charts/qa/cluster-a/values.yaml
    outFile: ./out/charts/my-chart/values.yaml
# Render manifests to ./out, commit, push, etc...

Given the following sample input files:

charts/my-chart/values.yaml

service:
  enabled: false

charts/qa/values.yaml

service:
  enabled: true

charts/qa/cluster-a/values.yaml

service:
  type: LoadBalancer

The step would produce the following output:

charts/my-chart/values.yaml

service:
  enabled: true
  type: LoadBalancer