add keyword to dynamically exclude auto discovered applications

README.md

@@ -108,6 +108,33 @@ While the above is doable with any of the other templating tools, `autoapps` kee
 the `Application` CRD, enables runtime configuration, and simplifies "glue" templating with auto discovery of 
 `Applications`.
 
+### Dynamically skipping/ignoring applications
+
+`autoapps` will only render Applications where `metadata.annotations.autoapps` exists.  If the annotation is missing
+from the Application, then it will be ignored.  In cases where a user would want to dynamically include an Application
+based off some values from a parent Applicaiton, the exlusive value `skip` is used to ignore.  Combined with `envsubst`
+formatting, an Application can be included unless an environment variable is included:
+
+```yaml
+# NOTE: Portions of the complete spec are skipped below for brevity
+apiVersion: argoproj.io/v1alpha1
+kind: Application
+metadata:
+  name: mocha
+  annotations:
+    argocd.argoproj.io/sync-wave: "1"
+    autoapps: "${AUTOAPPS_SKIP_MOCHA:+skip}"
+```
+
+In the above example, if the Application was autodiscovered by a parent application that defined `AUTOAPPS_SKIP_APP1`,
+then the application `mocha` as a whole will be skipped.
+
+The syntax above reads as:
+
+```
+If AUTO_APPS_SKIP_MOCHA is set, evaluate expression as skip, otherwise as empty string
+```
+
 ## Work in progress
 
 * "safe" environment variable substitution

go.mod

@@ -3,6 +3,7 @@ module github.com/joshrwolf/autoapps
 go 1.14
 
 require (
+	github.com/a8m/envsubst v1.2.0 // indirect
 	github.com/drone/envsubst v1.0.2
 	github.com/rancher/wrangler-cli v0.0.0-20200712180548-91e38f783aa5
 	github.com/sirupsen/logrus v1.6.0

go.sum

@@ -17,6 +17,8 @@ github.com/PuerkitoBio/purell v1.1.0/go.mod h1:c11w/QuzBsJSee3cPx9rAFu61PvFxuPbt
 github.com/PuerkitoBio/purell v1.1.1/go.mod h1:c11w/QuzBsJSee3cPx9rAFu61PvFxuPbtSwDGJws/X0=
 github.com/PuerkitoBio/urlesc v0.0.0-20160726150825-5bd2802263f2/go.mod h1:uGdkoq3SwY9Y+13GIhn11/XLaGBb4BfwItxLd5jeuXE=
 github.com/PuerkitoBio/urlesc v0.0.0-20170810143723-de5bf2ad4578/go.mod h1:uGdkoq3SwY9Y+13GIhn11/XLaGBb4BfwItxLd5jeuXE=
+github.com/a8m/envsubst v1.2.0 h1:yvzAhJD2QKdo35Ut03wIfXQmg+ta3wC/1bskfZynz+Q=
+github.com/a8m/envsubst v1.2.0/go.mod h1:PpvLvNWa+Rvu/10qXmFbFiGICIU5hZvFJNPCCkUaObg=
 github.com/agnivade/levenshtein v1.0.1/go.mod h1:CURSv5d9Uaml+FovSIICkLbAUZ9S4RqaHDIsdSBg7lM=
 github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
 github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf/go.mod h1:ybxpYRFXyAe+OPACYpWeL0wqObRcbAqCMya13uyzqw0=

main.go

@@ -9,12 +9,15 @@ import (
 	"io/ioutil"
 	"os"
 	"path/filepath"
-	"github.com/drone/envsubst"
+	"github.com/a8m/envsubst"
 	"strings"
 )
 
 const (
 	autoAppsFlag = "autoapps"
+	autoAppsAnnotationSkipVal = "skip"
+	argoAPIVersion = "argoproj.io/v1alpha1"
+	argoAppKind = "Application"
 )
 
 type Generate struct {
@@ -58,6 +61,18 @@ type MiniApp struct {
 	}
 }
 
+type App struct {
+	ApiVersion string `yaml:"apiVersion"`
+	Kind string `yaml:"kind"`
+	Metadata struct {
+		Annotations map[string]string `yaml:"annotations"`
+	}
+}
+
+type Metadata struct {
+	Annotations map[string]string `yaml:"annotations"`
+}
+
 func walkForApps(base string) (apps []string, err error) {
 	err = filepath.Walk(base, func(path string, info os.FileInfo, err error) error {
 		if err != nil {
@@ -66,21 +81,22 @@ func walkForApps(base string) (apps []string, err error) {
 
 		// Only care about valid yaml files
 		if ext := filepath.Ext(path); ext == ".yaml" || ext == ".yml" {
-			var a MiniApp
-			dat, err := ioutil.ReadFile(path)
+			data, err := ioutil.ReadFile(path)
 			if err != nil {
 				return err
 			}
 
-			err = yaml.Unmarshal(dat, &a)
-			if err != nil {
-				//logrus.Warnf("Failed to unmarshal %s: %v", path, err)
+			// TODO: This whole thing is some laaaazy logic flow
+			isApp, _ := isApp(data)
+			if !isApp {
+				// Bailout if it's not an app, we don't care anymore
+				return nil
 			}
 
-			if a.ApiVersion == "argoproj.io/v1alpha1" && a.Kind == "Application" {
-				if _, ok := a.Metadata.Annotations[autoAppsFlag]; ok {
-					apps = append(apps, safeEnvSubst(string(dat)))
-				}
+			// Render envsubst
+			render, substitutedApp := safeEnvSubst(data)
+			if render {
+				apps = append(apps, substitutedApp)
 			}
 		}
 		return nil
@@ -93,13 +109,59 @@ func walkForApps(base string) (apps []string, err error) {
 	return apps, nil
 }
 
+func isApp(data []byte) (bool, App) {
+	var a App
+	isApp := false
+
+	err := yaml.Unmarshal(data, &a)
+	if err != nil {}
+
+	// Check if this is an app
+	if a.ApiVersion == argoAPIVersion && a.Kind == argoAppKind {
+		isApp = true
+	}
+
+	return isApp, a
+}
+
+func isAutoApp(data []byte) (bool, MiniApp) {
+	var m MiniApp
+
+	err := yaml.Unmarshal(data, &m)
+	// Gobble up errors, need to keep stdout clean and stderr empty
+	if err != nil {}
+
+	// Check if this is an autoapp
+	if m.ApiVersion == argoAPIVersion && m.Kind	== argoAppKind {
+		if _, ok := m.Metadata.Annotations[autoAppsFlag]; ok {
+			return true, m
+		}
+	}
+
+	return false, m
+}
+
 // TODO: Need to implement a way to make this "safe" and only support _allowed_ environment variables
 //		 Make it obvious how "allowed" envs are determined
-func safeEnvSubst(original string) string {
-	substituted, err := envsubst.EvalEnv(original)
+func safeEnvSubst(original []byte) (bool, string) {
+	render := false
+
+	substituted, err := envsubst.Bytes(original)
 	if err != nil {
 		logrus.Fatalf("Failed to substitute: %v", err)
 	}
 
-	return substituted
+	// Only return valid yaml if annotations trigger is true
+	var a App
+	err = yaml.Unmarshal(substituted, &a)
+	if err != nil {}
+
+	if val, ok := a.Metadata.Annotations[autoAppsFlag]; ok {
+		if val != autoAppsAnnotationSkipVal {
+			render = true
+			return render, string(substituted)
+		}
+	}
+
+	return render, ""
 }

testdata/app1.yaml

@@ -1,3 +1,4 @@
+# This is included unless AUTOAPPS_SKIP_APP1 exists at runtime
 apiVersion: argoproj.io/v1alpha1
 kind: Application
 metadata:
@@ -7,6 +8,7 @@ metadata:
     - resources-finalizer.argocd.argoproj.io
   annotations:
     argocd.argoproj.io/sync-wave: "1"
+    autoapps: ${AUTOAPPS_SKIP_APP1:+"skip"}
 spec:
   project: default
 

testdata/notanapp.yaml

@@ -1,3 +1,4 @@
+# This is _not_ included because it is not of the right kind / apiVersion
 apiVersion: argoproj.io/v1alpha1
 kind: NotAnApp
 metadata:

testdata/sub/app2.yaml

@@ -1,3 +1,4 @@
+# This is included unless AUTOAPPS_SKIP_APP2 exists at runtime
 apiVersion: argoproj.io/v1alpha1
 kind: Application
 metadata:
@@ -7,6 +8,7 @@ metadata:
     - resources-finalizer.argocd.argoproj.io
   annotations:
     argocd.argoproj.io/sync-wave: "1"
+    autoapps: ${AUTOAPPS_SKIP_APP2:+"skip"}
 spec:
   project: default
 

testdata/sub/app3.yaml → testdata/sub/nonincludedapp.yaml

@@ -1,13 +1,14 @@
+# This is not included because autoapps is not set to true
 apiVersion: argoproj.io/v1alpha1
 kind: Application
 metadata:
-  name: app3
+  name: nonincludedapp
   namespace: argocd
   finalizers:
     - resources-finalizer.argocd.argoproj.io
   annotations:
     argocd.argoproj.io/sync-wave: "1"
-    autoapps: "true"
+    autoapps: "skip"
 spec:
   project: default