fix: Add build env vars support for function deployment. (GoogleCloudPlatform#133)

* Add build env vars support for function deployment.

* Format.

* Format.

Author: ludoch

invoker/function-maven-plugin/src/main/java/com/google/cloud/functions/plugin/DeployFunction.java

@@ -200,11 +200,27 @@ public class DeployFunction extends CloudSdkMojo {
    */
   @Parameter(alias = "deploy.envvarsfile", property = "function.deploy.envvarsfile")
   String envVarsFile;
+  /**
+   * List of key-value pairs to set as build environment variables. All existing environment variables
+   * will be removed first.
+   */
+  @Parameter(alias = "deploy.setbuildenvvars", property = "function.deploy.setbuildenvvars")
+  Map<String, String> buildEnvironmentVariables;
+  /**
+   * Path to a local YAML file with definitions for all build environment variables. All existing
+   * environment variables will be removed before the new environment variables are added.
+   */
+  @Parameter(alias = "deploy.buildenvvarsfile", property = "function.deploy.buildenvvarsfile")
+  String buildEnvVarsFile;
 
   boolean hasEnvVariables() {
     return (this.environmentVariables != null && !this.environmentVariables.isEmpty());
   }
 
+  boolean hasBuildEnvVariables() {
+    return (this.buildEnvironmentVariables != null && !this.buildEnvironmentVariables.isEmpty());
+  }
+  
   // Select a downloaded Cloud SDK or a user defined Cloud SDK version.
   static Function<String, ManagedCloudSdk> newManagedSdkFactory() {
     return version -> {
@@ -331,6 +347,13 @@ public List<String> getCommands() {
     if (envVarsFile != null) {
       commands.add("--env-vars-file=" + envVarsFile);
     }
+    if (hasBuildEnvVariables()) {
+      Joiner.MapJoiner mapJoiner = Joiner.on(",").withKeyValueSeparator("=");
+      commands.add("--set-build-env-vars=" + mapJoiner.join(buildEnvironmentVariables));
+    }
+    if (buildEnvVarsFile != null) {
+      commands.add("--build-env-vars-file=" + buildEnvVarsFile);
+    }
     commands.add("--runtime=" + runtime);
 
     if (projectId != null) {

invoker/function-maven-plugin/src/test/java/com/google/cloud/functions/plugin/DeployFunctionTest.java

@@ -16,6 +16,7 @@ public class DeployFunctionTest {
   public void testDeployFunctionCommandLine() {
     DeployFunction mojo = new DeployFunction();
     mojo.envVarsFile = "myfile";
+    mojo.buildEnvVarsFile = "myfile2";
     mojo.functionTarget = "function";
     mojo.ignoreFile = "ff";
     mojo.maxInstances = new Integer(3);
@@ -30,6 +31,7 @@ public void testDeployFunctionCommandLine() {
     mojo.triggerHttp = true;
     mojo.allowUnauthenticated = true;
     mojo.environmentVariables = ImmutableMap.of("env1", "a", "env2", "b");
+    mojo.buildEnvironmentVariables = ImmutableMap.of("env1", "a", "env2", "b");
     List<String> expected =
         ImmutableList.of(
             "functions",
@@ -49,6 +51,8 @@ public void testDeployFunctionCommandLine() {
             "--max-instances=3",
             "--set-env-vars=env1=a,env2=b",
             "--env-vars-file=myfile",
+            "--set-build-env-vars=env1=a,env2=b",
+            "--build-env-vars-file=myfile2",
             "--runtime=java11");
     assertThat(mojo.getCommands()).isEqualTo(expected);
   }