feat(context): allow explicit variables to be defined as argument

These changes allows variables to be defined when executing
`kontemplate` via one or more `--variable` arguments.

With this in place one can either define new variables or override
existing variables loaded from a file:

```
$ kontemplate apply --variable version=v1.0 example/fancy-app.yaml
```

This avoids the need to write variables into a temporary file that is
only needed to provide "external variables" into resource sets.

Closes https://github.com/tazjin/kontemplate/issues/122
This commit is contained in:
Phillip Johnsen 2018-05-30 21:43:31 +02:00 committed by Vincent Ambo
parent 09869cf8fc
commit 5cf9d53e80
3 changed files with 49 additions and 0 deletions

View file

@ -12,6 +12,7 @@ package context
import (
"fmt"
"path"
"strings"
"github.com/tazjin/kontemplate/util"
)
@ -158,3 +159,23 @@ func loadDefaultValues(rs *ResourceSet, c *Context) *map[string]interface{} {
// errors here.
return &rs.Values
}
// New variables can be defined or default values overridden with command line arguments when executing kontemplate.
func (ctx *Context) SetVariablesFromArguments(vars *[]string) error {
// Resource set files might not have defined any global variables, if so we have to
// create that a map before potentially writing variables into it
if ctx.Global == nil {
ctx.Global = make(map[string]interface{}, len(*vars))
}
for _, v := range *vars {
varParts := strings.Split(v, "=")
if len(varParts) != 2 {
return fmt.Errorf(`invalid explicit variable provided (%s), name and value should be divided with "="`, v)
}
ctx.Global[varParts[0]] = varParts[1]
}
return nil
}

View file

@ -280,3 +280,25 @@ func TestExplicitSubresourcePathLoading(t *testing.T) {
t.Fail()
}
}
func TestSetVariablesFromArguments(t *testing.T) {
vars := []string{"version=some-service-version"}
ctx, _ := LoadContextFromFile("testdata/default-loading.yaml")
if err := ctx.SetVariablesFromArguments(&vars); err != nil {
t.Error(err)
}
if version := ctx.Global["version"]; version != "some-service-version" {
t.Errorf(`Expected variable "version" to have value "some-service-version" but was "%s"`, version)
}
}
func TestSetInvalidVariablesFromArguments(t *testing.T) {
vars := []string{"version: some-service-version"}
ctx, _ := LoadContextFromFile("testdata/default-loading.yaml")
if err := ctx.SetVariablesFromArguments(&vars); err == nil {
t.Error("Expected invalid variable to return an error")
}
}

View file

@ -37,6 +37,7 @@ var (
// Global flags
includes = app.Flag("include", "Resource sets to include explicitly").Short('i').Strings()
excludes = app.Flag("exclude", "Resource sets to exclude explicitly").Short('e').Strings()
variables = app.Flag("var", "Provide variables to templates explicitly").Strings()
// Commands
template = app.Command("template", "Template resource sets and print them")
@ -188,6 +189,11 @@ func loadContextAndResources(file *string) (*context.Context, *[]templater.Rende
app.Fatalf("Error loading context: %v\n", err)
}
err = ctx.SetVariablesFromArguments(variables)
if err != nil {
app.Fatalf("Error setting explicit variables in context: %v\n", err)
}
resources, err := templater.LoadAndApplyTemplates(includes, excludes, ctx)
if err != nil {
app.Fatalf("Error templating resource sets: %v\n", err)