Bogie

A templating tool for Kubernetes clusters.

Running Bogie

Bogie can be run with a single template, but, is most useful with a manifest file, which describes the entire cluster state, and allows for greater template reuse. Generated manifests can be written to a directory, a single file, or stdout.

Run the following manifest with bogie template -m path/to/manifest.yaml.

out_path: releases
out_file: release.yaml
out_format: dir
env_file: path/to/global/vars/values.yaml
ignore_file: ./.bogieignore
skip_image_lookup: false
app_regex: .*
applications:
- name: my-templates
  templates: path/to/templates
  values:
  - path/to/templates/values.yaml
  - path/to/templates/env.values.yaml
  override_vars:
  - app.secrets.key=value
- name: my-other-templates
  templates: path/to/templates
  env: production
  override_vars:
  - app.secrets.key=value
- name: my-other-other-templates
  templates: path/to/templates

Note: Bogie supports file paths and remote Github repos for templates, values, _helpers.tmpl, and .bogieignore files. For private Github repos export a GITHUB_TOKEN variable. For more information on creating a personal API token see https://github.com/blog/1509-personal-api-tokens.

The manifest file supports the following keys.

• out_format output format, (dir|file|stdout).
• out_path output directory for file and dir outputs.
• out_file output file name.
• env_file global values file.
• ignore_file global .bogieignore file.
• skip_image_lookup skip the image lookup in latestImage template function.
• app_regex only build apps with names that match regex
• applications list of applications.
  • name name of the output directory. (the directory maintains the original structure with the exception of this name)
  • templates templates directory.
  • values list of values files, when omitted, Bogie will attempt to load values.yaml from the templates directory root.
  • env when set Bogie will attempt to load env.values.yaml from the templates directory root.
  • override_vars list of individual values in the format of app.secrets.key=value.

Bogie can also be run without a manifest:

bogie template \
  -t path/to/templates \
  -v path/to/templates/env.values.yaml \
  -v path/to/templates/values.yaml \
  -e path/to/global/vars/values.yaml \
  -o dir

To see the full list of supported flags run bogie template help.

Directory Structure

Bogie does not enforce a strict template directory structure. It walks the template directory and sends the files to the rendering engine. The only files required to be in template directory root are _helpers.tmpl and .bogieignore. When no values are specified bogie attempt to load values.yaml from the template directory root and when an env is provided it will also attempt to load env.values.yaml.

Templates

Bogie uses the Golang text/template package for templating and defaults to triple-curlies {{{ .Values.key }}} so that manifests containing Golang templates can be generated.

Values

Bogie values files are sops encrypted yaml files. Bogie will automatically decrypt the files and Unmasrshal them into a Values map when generating the templates and can be accessed in the templates like {{{ .Values.key }}}. The files get merged in the following order:

1. The global values file.
2. The values.yaml file (when no values files provided).
3. The values files in order that they are provided.
4. The env.values.yaml. (when env is provided).

Finally override vars in the format of path.to.key=value get merged into the struct.

Partials

Partials can be added to the templates directory root as _helpers.tmpl files, and will be merged in with the templates.

Ignore Files

Files excluded in .bogieignore will not be templated.

Functions

Bogie adds all the template functions from Masterminds/sprig and adds a few custom template functions as well:

• latestImage - bogie:{{{ latestImage "latest" }}} using commit SHA tags in kubernetes deployments and latest in the manifest will trigger a new deployment whenever the manifest is applied, even if nothing changed. latestImage looks up the corresponding commit SHA tag based on latest or staging etc.
• readDir - {{{ readDir "path/to/dir" }}} returns a map of file names and file contents.
• decryptDir - {{{ decryptDir "path/to/dir" }}} returns a map of file names and dycrypted file contents.
• readFile - {{{ readFile "path/to/file" }}} returns file contents.
• decryptFile - {{{ decryptFile "path/to/file" }}} returns dycrypted file contents.
• basicAuth - {{{ basicAuth .Values.user .Values.password }}} returns a SHA-1 hash of your password in the format of user:{SHA}password.
• json - {{{ json .Values.json_string }}} converts a JSON string into an object.
• jsonArray - {{{ json .Values.json_array_string }}} converts a JSON string into a slice.
• toJSON - {{{ toJSON .Values.object }}} converts an object to a JSON document.
• yaml - {{{ yaml .Values.yaml_string }}} converts a YAML string into an object.
• yamlArray - {{{ yaml .Values.yaml_array_string }}} converts a YAML string into a slice.
• toYAML - {{{ toYAML .Values.object }}} converts an object to a YAML document.
• toml - {{{ yaml .Values.toml_string }}} converts a TOML string into an object.
• toTOML - {{{ toTOML .Values.object }}} converts an object to a TOML document.

Credits

• This project began as a fork of Gomplate but at this point is almost a complete rewrite.
• The ignore package was copied from Helm and slightly modified.