Merge pull request #349 from duckpuppy/use_traits

Create a Pluggable trait to DRY up terraform commands
manheim · Mar 23, 2021 · 4a56d34 · 4a56d34
2 parents 7ca47df + 00aec41
commit 4a56d34
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diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -2,10 +2,9 @@
 
 * [Issue #344](https://github.com/manheim/terraform-pipeline/issues/344) Add PLAN_ONLY parameter to PlanOnlyPlugin
   * **BREAKING CHANGE** This change is a breaking change. Prior to this update, applying the PlanOnlyPlugin would restrict the pipeline to only running `terraform plan`. This update changes behavior to simply providing a `PLAN_ONLY` boolean parameter that can be set to restrict the build behavior. It defaults to `false`.
-* [Issue #347](https://github.com/manheim/terraform-pipeline/pull/348)
-  Feature: TerraformOutputOnlyPlugin - can restrict a pipeline run to
-  displaying the current state outputs only via new job parameters.
+* [Issue #347](https://github.com/manheim/terraform-pipeline/pull/348) Feature: TerraformOutputOnlyPlugin - can restrict a pipeline run to displaying the current state outputs only via new job parameters.
 * [Issue #318](https://github.com/manheim/terraform-pipeline/issues/318) Feature: Show environment on confirm command page
+* [Issue #349](https://github.com/manheim/terraform-pipeline/pull/349) Extract plugin handling to a `Pluggable` trait to DRY up the existing TerraformCommand classes.
 
 # v5.15
 

diff --git a/src/Pluggable.groovy b/src/Pluggable.groovy
@@ -0,0 +1,51 @@
+/**
+ * The `Pluggable` trait can be used to add plugin management to a class. It
+ * takes as a type parameter the plugin type it accepts.
+ */
+trait Pluggable<T> implements Resettable {
+    private static plugins = []
+    private appliedPlugins = []
+
+    /**
+     * Assures that all plugins are applied, and are applied at most once. It
+     * can be safely called multiple times.
+     */
+    public applyPlugins() {
+        def remainingPlugins = plugins - appliedPlugins
+
+        for (T plugin in remainingPlugins) {
+            plugin.apply(this)
+            appliedPlugins << plugin
+        }
+    }
+
+    /**
+     * Accepts a plugin of the appropriate type and adds it to the list of plugins.
+     *
+     * @param plugin The plugin to add
+     */
+    public static void addPlugin(T plugin) {
+        plugins << plugin
+    }
+
+    public static void setPlugins(plugins) {
+        this.plugins = plugins
+    }
+
+    public static getPlugins() {
+        return plugins
+    }
+
+    /**
+     * Reset plugins will reset the plugin list to a default set of plugins.
+     *
+     * @param defaultPlugins list of plugins to set, default: []
+     */
+    public static void resetPlugins(defaultPlugins = []) {
+        this.plugins = defaultPlugins.clone()
+    }
+
+    public static void reset() {
+        this.resetPlugins()
+    }
+}
diff --git a/src/TerraformApplyCommand.groovy b/src/TerraformApplyCommand.groovy
@@ -1,13 +1,11 @@
-class TerraformApplyCommand implements TerraformCommand, Resettable {
+class TerraformApplyCommand implements TerraformCommand, Pluggable<TerraformApplyCommandPlugin> {
     private boolean input = false
     private String terraformBinary = "terraform"
     private String command = "apply"
     String environment
     private prefixes = []
     private suffixes = []
     private args = []
-    private static plugins = []
-    private appliedPlugins = []
     private String directory
     private Closure variablePattern
     private Closure mapPattern
@@ -76,8 +74,7 @@ class TerraformApplyCommand implements TerraformCommand, Resettable {
     }
 
     public String toString() {
-        applyPluginsOnce()
-
+        applyPlugins()
         def pieces = []
         pieces += prefixes
         pieces << terraformBinary
@@ -95,33 +92,12 @@ class TerraformApplyCommand implements TerraformCommand, Resettable {
         return pieces.join(' ')
     }
 
-    private applyPluginsOnce() {
-        def remainingPlugins = plugins - appliedPlugins
-
-        for (TerraformApplyCommandPlugin plugin in remainingPlugins) {
-            plugin.apply(this)
-            appliedPlugins << plugin
-        }
-    }
-
-    public static void addPlugin(TerraformApplyCommandPlugin plugin) {
-        plugins << plugin
-    }
-
     public static TerraformApplyCommand instanceFor(String environment) {
         return new TerraformApplyCommand(environment)
             .withInput(false)
             .withArgument("-auto-approve")
     }
 
-    public static getPlugins() {
-        return plugins
-    }
-
-    public static reset() {
-        this.plugins = []
-    }
-
     public String getEnvironment() {
         return environment
     }

diff --git a/src/TerraformCommand.groovy b/src/TerraformCommand.groovy
@@ -1,3 +1,6 @@
+/**
+ * `TerraformCommand` is an interface that can be implemented by a class that wraps a Terraform command.
+ */
 interface TerraformCommand {
     public String getEnvironment()
 }
diff --git a/src/TerraformFormatCommand.groovy b/src/TerraformFormatCommand.groovy
@@ -1,6 +1,4 @@
-class TerraformFormatCommand implements Resettable {
-    private static globalPlugins = []
-    private appliedPlugins = []
+class TerraformFormatCommand implements Pluggable<TerraformFormatCommandPlugin> {
     private static boolean check = false
     private static boolean recursive = false
     private static boolean diff = false
@@ -10,8 +8,7 @@ class TerraformFormatCommand implements Resettable {
     private Closure diffOptionPattern
 
     public String toString() {
-        applyPluginsOnce()
-
+        applyPlugins()
         def pattern
         def parts = []
         parts << 'terraform fmt'
@@ -29,19 +26,6 @@ class TerraformFormatCommand implements Resettable {
         return parts.join(' ')
     }
 
-    public static addPlugin(TerraformFormatCommandPlugin plugin) {
-        this.globalPlugins << plugin
-    }
-
-    private applyPluginsOnce() {
-        def remainingPlugins = globalPlugins - appliedPlugins
-
-        for (TerraformFormatCommandPlugin plugin in remainingPlugins) {
-            plugin.apply(this)
-            appliedPlugins << plugin
-        }
-    }
-
     public static withCheck(newValue = true) {
         check = newValue
         return this
@@ -76,10 +60,10 @@ class TerraformFormatCommand implements Resettable {
         return this
     }
 
-    public static reset() {
+    public static void reset() {
         check = false
         recursive = false
         diff = false
-        globalPlugins = []
+        resetPlugins()
     }
 }
diff --git a/src/TerraformInitCommand.groovy b/src/TerraformInitCommand.groovy
@@ -1,4 +1,4 @@
-class TerraformInitCommand implements Resettable {
+class TerraformInitCommand implements TerraformCommand, Pluggable<TerraformInitCommandPlugin> {
     private boolean input = false
     private String terraformBinary = "terraform"
     private String command = "init"
@@ -9,9 +9,6 @@ class TerraformInitCommand implements Resettable {
     private boolean doBackend = true
     private String directory
 
-    private static globalPlugins = []
-    private appliedPlugins = []
-
     public TerraformInitCommand(String environment) {
         this.environment = environment
     }
@@ -47,8 +44,7 @@ class TerraformInitCommand implements Resettable {
     }
 
     public String toString() {
-        applyPluginsOnce()
-
+        applyPlugins()
         def pieces = []
         pieces += prefixes
         pieces << terraformBinary
@@ -72,29 +68,7 @@ class TerraformInitCommand implements Resettable {
         return pieces.join(' ')
     }
 
-    private applyPluginsOnce() {
-        def remainingPlugins = globalPlugins - appliedPlugins
-
-        for (TerraformInitCommandPlugin plugin in remainingPlugins) {
-            plugin.apply(this)
-            appliedPlugins << plugin
-        }
-    }
-
-    public static void addPlugin(TerraformInitCommandPlugin plugin) {
-        this.globalPlugins << plugin
-    }
-
     public static TerraformInitCommand instanceFor(String environment) {
         return new TerraformInitCommand(environment)
     }
-
-    public static getPlugins() {
-        return this.globalPlugins
-    }
-
-    public static reset() {
-        globalPlugins = []
-        // This is awkward - what about the applied plugins...?
-    }
 }
diff --git a/src/TerraformOutputCommand.groovy b/src/TerraformOutputCommand.groovy
@@ -1,13 +1,10 @@
-class TerraformOutputCommand implements TerraformCommand, Resettable {
-    private static final DEFAULT_PLUGINS = []
+class TerraformOutputCommand implements TerraformCommand, Pluggable<TerraformOutputCommandPlugin> {
     private String command = "output"
-    private boolean json = false
-    private String redirectFile
     private String terraformBinary = "terraform"
     String environment
+    private boolean json = false
+    private String redirectFile
     private String stateFilePath
-    private static plugins = DEFAULT_PLUGINS.clone()
-    private appliedPlugins = []
 
     public TerraformOutputCommand(String environment) {
         this.environment = environment
@@ -24,8 +21,7 @@ class TerraformOutputCommand implements TerraformCommand, Resettable {
     }
 
     public String toString() {
-        applyPluginsOnce()
-
+        applyPlugins()
         def pieces = []
         pieces << terraformBinary
         pieces << command
@@ -41,31 +37,10 @@ class TerraformOutputCommand implements TerraformCommand, Resettable {
         return pieces.join(' ')
     }
 
-    private applyPluginsOnce() {
-        def remainingPlugins = plugins - appliedPlugins
-
-        for (TerraformOutputCommandPlugin plugin in remainingPlugins) {
-            plugin.apply(this)
-            appliedPlugins << plugin
-        }
-    }
-
-    public static addPlugin(TerraformOutputCommandPlugin plugin) {
-        plugins << plugin
-    }
-
     public static TerraformOutputCommand instanceFor(String environment) {
         return new TerraformOutputCommand(environment).withJson(false)
     }
 
-    public static getPlugins() {
-        return plugins
-    }
-
-    public static reset() {
-        this.plugins = DEFAULT_PLUGINS.clone()
-    }
-
     public String getEnvironment() {
         return environment
     }

diff --git a/src/TerraformPlanCommand.groovy b/src/TerraformPlanCommand.groovy
@@ -1,14 +1,11 @@
-class TerraformPlanCommand implements TerraformCommand, Resettable {
-    private static final DEFAULT_PLUGINS = []
+class TerraformPlanCommand implements TerraformCommand, Pluggable<TerraformPlanCommandPlugin> {
     private boolean input = false
     private String terraformBinary = "terraform"
     private String command = "plan"
     String environment
     private prefixes = []
     private suffixes = []
     private arguments = []
-    private static plugins = DEFAULT_PLUGINS.clone()
-    private appliedPlugins = []
     private String directory
     private String errorFile
     private Closure variablePattern
@@ -78,8 +75,7 @@ class TerraformPlanCommand implements TerraformCommand, Resettable {
     }
 
     public String toString() {
-        applyPluginsOnce()
-
+        applyPlugins()
         def pieces = []
         pieces = pieces + prefixes
         pieces << terraformBinary
@@ -103,32 +99,11 @@ class TerraformPlanCommand implements TerraformCommand, Resettable {
         return pieces.join(' ')
     }
 
-    private applyPluginsOnce() {
-        def remainingPlugins = plugins - appliedPlugins
-
-        for (TerraformPlanCommandPlugin plugin in remainingPlugins) {
-            plugin.apply(this)
-            appliedPlugins << plugin
-        }
-    }
-
-    public static addPlugin(TerraformPlanCommandPlugin plugin) {
-        plugins << plugin
-    }
-
     public static TerraformPlanCommand instanceFor(String environment) {
         return new TerraformPlanCommand(environment)
             .withInput(false)
     }
 
-    public static getPlugins() {
-        return plugins
-    }
-
-    public static reset() {
-        this.plugins = DEFAULT_PLUGINS.clone()
-    }
-
     public String getEnvironment() {
         return environment
     }