Address comments on publish usage

* addresses possible confusion with publish command
* adds a note on build and publish functions to refactor
at a later date into a struct

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <[email protected]>

Author: alexellis

README.md

@@ -77,6 +77,8 @@ The main commands supported by the CLI are:
 * `faas-cli push` - pushes Docker images into a registry
 * `faas-cli deploy` - deploys the functions into a local or remote OpenFaaS gateway
 
+* `faas-cli publish` - build and push multi-arch images for CI and release artifacts
+
 * `faas-cli remove` - removes the functions from a local or remote OpenFaaS gateway
 * `faas-cli invoke` - invokes the functions and reads from STDIN for the body of the request
 * `faas-cli store` - allows browsing and deploying OpenFaaS store functions

builder/build.go

@@ -23,6 +23,7 @@ import (
 const AdditionalPackageBuildArg = "ADDITIONAL_PACKAGE"
 
 // BuildImage construct Docker image from function parameters
+// TODO: refactor signature to a struct to simplify the length of the method header
 func BuildImage(image string, handler string, functionName string, language string, nocache bool, squash bool, shrinkwrap bool, buildArgMap map[string]string, buildOptions []string, tagMode schema.BuildFormat, buildLabelMap map[string]string, quietBuild bool, copyExtraPaths []string) error {
 
 	if stack.IsValidTemplate(language) {

builder/publish.go

@@ -14,6 +14,7 @@ import (
 )
 
 // PublishImage will publish images as multi-arch
+// TODO: refactor signature to a struct to simplify the length of the method header
 func PublishImage(image string, handler string, functionName string, language string, nocache bool, squash bool, shrinkwrap bool, buildArgMap map[string]string,
 	buildOptions []string, tagMode schema.BuildFormat, buildLabelMap map[string]string, quietBuild bool, copyExtraPaths []string, platforms string, extraTags []string) error {
 

commands/publish.go

@@ -66,10 +66,16 @@ var publishCmd = &cobra.Command{
                    [--copy-extra PATH]
                    [--tag <sha|branch|describe>]
                    [--platforms linux/arm/v7]`,
-	Short: "Builds and pushes multi-arch OpenFaaS functions",
-	Long: `Builds and pushes multi-arch OpenFaaS functions using Docker buildx.
-A multi-arch template is required. Images will not be available in the 
-local Docker library. This command only works when a YAML file is specified.
+	Short: "Builds and pushes multi-arch OpenFaaS container images",
+	Long: `Builds and pushes multi-arch OpenFaaS container images using Docker buildx.
+Most users will want faas-cli build or faas-cli up for development and testing.
+This command is designed to make releasing and publishing multi-arch container 
+images easier.
+
+A stack.yaml file is required, and any images that are built will not be 
+available in the local Docker library. This is due to technical constraints in 
+Docker and buildx. You must use a multi-arch template to use this command with 
+correctly configured TARGETPLATFORM and BUILDPLATFORM arguments.
 
 See also: faas-cli build`,
 	Example: `  faas-cli publish --platforms linux/amd64,linux/arm64,linux/arm/7