Merge pull request #81 from rittneje/choose-role-at-runtime

Allow specifying AWS role at runtime

Author: escoem

src/main/java/com/cloudbees/jenkins/plugins/awscredentials/AWSCredentialsImpl.java

@@ -28,8 +28,8 @@
 import com.amazonaws.AmazonClientException;
 import com.amazonaws.AmazonServiceException;
 import com.amazonaws.ClientConfiguration;
-import com.amazonaws.SdkClientException;
 import com.amazonaws.auth.AWSCredentials;
+import com.amazonaws.auth.AWSCredentialsProvider;
 import com.amazonaws.auth.AWSStaticCredentialsProvider;
 import com.amazonaws.auth.BasicAWSCredentials;
 import com.amazonaws.auth.BasicSessionCredentials;
@@ -131,35 +131,16 @@ public AWSCredentials getCredentials() {
         if (StringUtils.isBlank(iamRoleArn)) {
             return initialCredentials;
         } else {
-            // Check for available region from the SDK, otherwise specify default
-            String clientRegion = null;
-            DefaultAwsRegionProviderChain sdkRegionLookup = new DefaultAwsRegionProviderChain();
-            try {
-                clientRegion = sdkRegionLookup.getRegion();
-            } catch (RuntimeException e) {
-                LOGGER.log(Level.WARNING, "Could not find default region using SDK lookup.", e);
-            }
-            if (clientRegion == null) {
-                clientRegion = Regions.DEFAULT_REGION.getName();
-            }
-
-            ClientConfiguration clientConfiguration = getClientConfiguration();
-
-            AWSSecurityTokenService client;
+            AWSCredentialsProvider baseProvider;
             // Handle the case of delegation to instance profile
             if (StringUtils.isBlank(accessKey) && StringUtils.isBlank(secretKey.getPlainText())) {
-                client = AWSSecurityTokenServiceClientBuilder.standard()
-                        .withRegion(clientRegion)
-                        .withClientConfiguration(clientConfiguration)
-                        .build();
+                baseProvider = null;
             } else {
-                client = AWSSecurityTokenServiceClientBuilder.standard()
-                        .withCredentials(new AWSStaticCredentialsProvider(initialCredentials))
-                        .withRegion(clientRegion)
-                        .withClientConfiguration(clientConfiguration)
-                        .build();
+               baseProvider = new AWSStaticCredentialsProvider(initialCredentials);
             }
 
+            AWSSecurityTokenService client = buildStsClient(baseProvider);
+
             AssumeRoleRequest assumeRequest = createAssumeRoleRequest(iamRoleArn)
                     .withDurationSeconds(this.getStsTokenDuration());
 
@@ -200,6 +181,30 @@ public String getDisplayName() {
         return accessKey + ":" + iamRoleArn;
     }
 
+    /*package*/ static AWSSecurityTokenService buildStsClient(AWSCredentialsProvider provider) {
+        // Check for available region from the SDK, otherwise specify default
+        String clientRegion = null;
+        DefaultAwsRegionProviderChain sdkRegionLookup = new DefaultAwsRegionProviderChain();
+        try {
+            clientRegion = sdkRegionLookup.getRegion();
+        } catch(RuntimeException e) {
+            LOGGER.log(Level.WARNING, "Could not find default region using SDK lookup.", e);
+        }
+        if (clientRegion == null) {
+            clientRegion = Regions.DEFAULT_REGION.getName();
+        }
+
+        AWSSecurityTokenServiceClientBuilder builder = AWSSecurityTokenServiceClientBuilder.standard()
+                        .withRegion(clientRegion)
+                        .withClientConfiguration(getClientConfiguration());
+
+        if (provider != null) {
+            builder = builder.withCredentials(provider);
+        }
+
+        return builder.build();
+    }
+
     private static AssumeRoleRequest createAssumeRoleRequest(String iamRoleArn) {
         return new AssumeRoleRequest()
                 .withRoleArn(iamRoleArn)

src/main/java/com/cloudbees/jenkins/plugins/awscredentials/AmazonWebServicesCredentialsBinding.java

@@ -27,6 +27,10 @@
 
 import com.amazonaws.auth.AWSCredentials;
 import com.amazonaws.auth.AWSSessionCredentials;
+import com.amazonaws.auth.AWSCredentialsProvider;
+import com.amazonaws.auth.AWSSessionCredentialsProvider;
+import com.amazonaws.auth.STSAssumeRoleSessionCredentialsProvider;
+import com.amazonaws.services.securitytoken.AWSSecurityTokenService;
 import edu.umd.cs.findbugs.annotations.NonNull;
 import edu.umd.cs.findbugs.annotations.Nullable;
 import hudson.Extension;
@@ -39,6 +43,7 @@
 import org.jenkinsci.plugins.credentialsbinding.MultiBinding;
 import org.jenkinsci.Symbol;
 import org.kohsuke.stapler.DataBoundConstructor;
+import org.kohsuke.stapler.DataBoundSetter;
 
 import javax.annotation.Nonnull;
 import java.io.IOException;
@@ -62,6 +67,10 @@ public class AmazonWebServicesCredentialsBinding extends MultiBinding<AmazonWebS
     @NonNull
     private final String secretKeyVariable;
 
+    private String roleArn;
+    private String roleSessionName;
+    private int roleSessionDurationSeconds;
+
     /**
      *
      * @param accessKeyVariable if {@code null}, {@value DEFAULT_ACCESS_KEY_ID_VARIABLE_NAME} will be used.
@@ -85,14 +94,35 @@ public String getSecretKeyVariable() {
         return secretKeyVariable;
     }
 
+    @DataBoundSetter
+    public void setRoleArn(String roleArn) {
+        this.roleArn = roleArn;
+    }
+
+    @DataBoundSetter
+    public void setRoleSessionName(String roleSessionName) {
+        this.roleSessionName = roleSessionName;
+    }
+
+    @DataBoundSetter
+    public void setRoleSessionDurationSeconds(int roleSessionDurationSeconds) {
+        this.roleSessionDurationSeconds = roleSessionDurationSeconds;
+    }
+
     @Override
     protected Class<AmazonWebServicesCredentials> type() {
         return AmazonWebServicesCredentials.class;
     }
 
     @Override
     public MultiEnvironment bind(@Nonnull Run<?, ?> build, FilePath workspace, Launcher launcher, TaskListener listener) throws IOException, InterruptedException {
-        AWSCredentials credentials = getCredentials(build).getCredentials();
+        AWSCredentialsProvider provider = getCredentials(build);
+        if (!StringUtils.isEmpty(this.roleArn)) {
+            provider = this.assumeRoleProvider(provider);
+        }
+
+        AWSCredentials credentials = provider.getCredentials();
+
         Map<String,String> m = new HashMap<String,String>();
         m.put(accessKeyVariable, credentials.getAWSAccessKeyId());
         m.put(secretKeyVariable, credentials.getAWSSecretKey());
@@ -104,9 +134,26 @@ public MultiEnvironment bind(@Nonnull Run<?, ?> build, FilePath workspace, Launc
         return new MultiEnvironment(m);
     }
 
+    private AWSSessionCredentialsProvider assumeRoleProvider(AWSCredentialsProvider baseProvider) {
+        AWSSecurityTokenService stsClient = AWSCredentialsImpl.buildStsClient(baseProvider);
+
+        String roleSessionName = StringUtils.defaultIfBlank(this.roleSessionName, "Jenkins");
+
+        STSAssumeRoleSessionCredentialsProvider.Builder assumeRoleProviderBuilder =
+                new STSAssumeRoleSessionCredentialsProvider.Builder(this.roleArn, roleSessionName)
+                .withStsClient(stsClient);
+
+        if (this.roleSessionDurationSeconds > 0) {
+            assumeRoleProviderBuilder = assumeRoleProviderBuilder
+                .withRoleSessionDurationSeconds(this.roleSessionDurationSeconds);
+        }
+
+        return assumeRoleProviderBuilder.build();
+    }
+
     @Override
     public Set<String> variables() {
-        return new HashSet<String>(Arrays.asList(accessKeyVariable, secretKeyVariable));
+        return new HashSet<String>(Arrays.asList(accessKeyVariable, secretKeyVariable, SESSION_TOKEN_VARIABLE_NAME));
     }
 
     @Symbol("aws")