github.com/koderover/helm@v2.17.0+incompatible/docs/chart_best_practices/conventions.md (about)

     1  # General Conventions
     2  
     3  This part of the Best Practices Guide explains general conventions.
     4  
     5  ## Chart Names
     6  
     7  Chart names should use lower case letters and numbers, and start with a letter.
     8  
     9  Hyphens (-) are allowed, but are known to be a little trickier to work with in Helm templates (see [issue #2192](https://github.com/helm/helm/issues/2192) for more information).
    10  
    11  Here are a few examples of good chart names from the [Helm Community Charts](https://github.com/helm/charts):
    12  
    13  ```
    14  drupal
    15  cert-manager
    16  oauth2-proxy
    17  ```
    18  
    19  Neither uppercase letters nor underscores should be used in chart names. Dots should not be used in chart names.
    20  
    21  The directory that contains a chart MUST have the same name as the chart. Thus, the chart `cert-manager` MUST be created in a directory called `cert-manager/`. This is not merely a stylistic detail, but a requirement of the Helm Chart format.
    22  
    23  ## Version Numbers
    24  
    25  Wherever possible, Helm uses [SemVer 2](https://semver.org) to represent version numbers. (Note that Docker image tags do not necessarily follow SemVer, and are thus considered an unfortunate exception to the rule.)
    26  
    27  When SemVer versions are stored in Kubernetes labels, we conventionally alter the `+` character to an `_` character, as labels do not allow the `+` sign as a value.
    28  
    29  ## Formatting YAML
    30  
    31  YAML files should be indented using _two spaces_ (and never tabs).
    32  
    33  ## Usage of the Words Helm, Tiller, and Chart
    34  
    35  There are a few small conventions followed for using the words Helm, helm, Tiller, and tiller.
    36  
    37  - Helm refers to the project, and is often used as an umbrella term
    38  - `helm` refers to the client-side command
    39  - Tiller is the proper name of the backend
    40  - `tiller` is the name of the binary run on the backend
    41  - The term 'chart' does not need to be capitalized, as it is not a proper noun.
    42  
    43  When in doubt, use _Helm_ (with an uppercase 'H').
    44  
    45  ## Restricting Tiller by Version
    46  
    47  A `Chart.yaml` file can specify a `tillerVersion` SemVer constraint:
    48  
    49  ```yaml
    50  name: mychart
    51  version: 0.2.0
    52  tillerVersion: ">=2.4.0"
    53  ```
    54  
    55  This constraint should be set when templates use a new feature that was not
    56  supported in older versions of Helm. While this parameter will accept sophisticated
    57  SemVer rules, the best practice is to default to the form `>=2.4.0`, where `2.4.0`
    58  is the version that introduced the new feature used in the chart.
    59  
    60  This feature was introduced in Helm 2.4.0, so any version of Tiller older than
    61  2.4.0 will simply ignore this field.