Helm Diff Plugin

This is a Helm plugin giving your a preview of what a helm upgrade would change. It basically generates a diff between the latest deployed version of a release and a helm upgrade --debug --dry-run. This can also be used to compare two revisions/versions of your helm release.

Install

Using Helm plugin manager (> 2.3.x)

helm plugin install https://github.com/databus23/helm-diff

Pre Helm 2.3.0 Installation

Pick a release tarball from the releases page.

Unpack the tarball in your helm plugins directory ($(helm home)/plugins).

E.g.

curl -L $TARBALL_URL | tar -C $(helm home)/plugins -xzv

Usage

The Helm Diff Plugin

* Shows a diff explaining what a helm upgrade would change:
    This fetches the currently deployed version of a release
  and compares it to a local chart plus values. This can be 
  used visualize what changes a helm upgrade will perform.

* Shows a diff explaining what had changed between two revisions:
    This fetches previously deployed versions of a release
  and compares them. This can be used visualize what changes 
  were made during revision change.

* Shows a diff explaining what a helm rollback would change:
    This fetches the currently deployed version of a release
  and compares it to adeployed versions of a release, that you 
  want to rollback. This can be used visualize what changes a 
  helm rollback will perform.

Usage:
  diff [flags]
  diff [command]

Available Commands:
  release     Shows diff between release's manifests
  revision    Shows diff between revision's manifests
  rollback    Show a diff explaining what a helm rollback could perform
  upgrade     Show a diff explaining what a helm upgrade would change.
  version     Show version of the helm diff plugin

Flags:
  -h, --help                   help for diff
      --no-color               remove colors from the output
      --reset-values           reset the values to the ones built into the chart and merge in any new values
      --reuse-values           reuse the last release's values and merge in any new values
      --set stringArray        set values on the command line (can specify multiple or separate values with commas: key1=val1,key2=val2)
      --suppress stringArray   allows suppression of the values listed in the diff output
  -q, --suppress-secrets       suppress secrets in the output
  -f, --values valueFiles      specify values in a YAML file (can specify multiple) (default [])
      --version string         specify the exact chart version to use. If this is not specified, the latest version is used

Additional help topics:
  diff          

Use "diff [command] --help" for more information about a command.

Commands:

upgrade:

$ helm diff upgrade -h
Show a diff explaining what a helm upgrade would change.

This fetches the currently deployed version of a release
and compares it to a chart plus values.
This can be used visualize what changes a helm upgrade will
perform.

Usage:
  diff upgrade [flags] [RELEASE] [CHART]

Examples:
  helm diff upgrade my-release stable/postgresql --values values.yaml

Flags:
  -h, --help                   help for upgrade
      --detailed-exitcode      return a non-zero exit code when there are changes
      --post-renderer string   the path to an executable to be used for post rendering. If it exists in $PATH, the binary will be used, otherwise it will try to look for the executable at the given path
      --reset-values           reset the values to the ones built into the chart and merge in any new values
      --reuse-values           reuse the last release's values and merge in any new values
      --set stringArray        set values on the command line (can specify multiple or separate values with commas: key1=val1,key2=val2)
      --suppress stringArray   allows suppression of the values listed in the diff output
  -q, --suppress-secrets       suppress secrets in the output
  -f, --values valueFiles      specify values in a YAML file (can specify multiple) (default [])
      --version string         specify the exact chart version to use. If this is not specified, the latest version is used

Global Flags:
      --no-color   remove colors from the output

release:

$ helm diff release -h

This command compares the manifests details of a different releases created from the same chart

It can be used to compare the manifests of

 - release1 with release2
	$ helm diff release [flags] release1 release2
   Example:
	$ helm diff release my-prod my-stage

Usage:
  diff release [flags] RELEASE release1 [release2]

Flags:
  -C, --context int            output NUM lines of context around changes (default -1)
  -h, --help                   help for release
      --home string            location of your Helm config. Overrides $HELM_HOME (default "/home/aananth/.helm")
      --include-tests          enable the diffing of the helm test hooks
      --suppress stringArray   allows suppression of the values listed in the diff output
  -q, --suppress-secrets       suppress secrets in the output
      --tls                    enable TLS for request
      --tls-ca-cert string     path to TLS CA certificate file (default "$HELM_HOME/ca.pem")
      --tls-cert string        path to TLS certificate file (default "$HELM_HOME/cert.pem")
      --tls-hostname string    the server name used to verify the hostname on the returned certificates from the server
      --tls-key string         path to TLS key file (default "$HELM_HOME/key.pem")
      --tls-verify             enable TLS for request and verify remote

Global Flags:
      --no-color   remove colors from the output

revision:

$ helm diff revision -h

This command compares the manifests details of a named release.

It can be used to compare the manifests of 
 
 - lastest REVISION with specified REVISION
	$ helm diff revision [flags] RELEASE REVISION1
   Example: 
	$ helm diff revision my-release 2

 - REVISION1 with REVISION2
	$ helm diff revision [flags] RELEASE REVISION1 REVISION2
   Example: 
	$ helm diff revision my-release 2 3

Usage:
  diff revision [flags] RELEASE REVISION1 [REVISION2]

Flags:
  -h, --help                   help for revision
      --suppress stringArray   allows suppression of the values listed in the diff output
  -q, --suppress-secrets       suppress secrets in the output

Global Flags:
      --no-color   remove colors from the output

rollback:

$ helm diff rollback -h

This command compares the laset manifests details of a named release 
with specific revision values to rollback.

It forecasts/visualizes changes, that a helm rollback could perform.

Usage:
  diff rollback [flags] [RELEASE] [REVISION]

Examples:
  helm diff rollback my-release 2

Flags:
  -h, --help                   help for rollback
      --suppress stringArray   allows suppression of the values listed in the diff output
  -q, --suppress-secrets       suppress secrets in the output

Global Flags:
      --no-color   remove colors from the output

Build

Clone the repository into your $GOPATH and then build it.

$ mkdir -p $GOPATH/src/github.com/databus23/
$ cd $GOPATH/src/github.com/databus23/
$ git clone https://github.com/databus23/helm-diff.git
$ cd helm-diff
$ make install

The above will install this plugin into your $HELM_HOME/plugins directory.

Prerequisites

• You need to have Go installed. Make sure to set $GOPATH

Running Tests

Automated tests are implemented with testing.

To run all tests:

go test -v ./...

Release

Set GITHUB_TOKEN and run:

$ make docker-run-release