Add support for dynamic usernames and passwords.

[closes #613]

Signed-off-by: Mark Paluch <mpaluch@paluch.biz>

Author: mp911de

src/main/java/io/r2dbc/postgresql/PostgresqlConnectionConfiguration.java

@@ -36,6 +36,8 @@
 import io.r2dbc.postgresql.message.backend.NoticeResponse;
 import io.r2dbc.postgresql.util.Assert;
 import io.r2dbc.postgresql.util.LogLevel;
+import org.reactivestreams.Publisher;
+import reactor.core.publisher.Mono;
 import reactor.netty.resources.LoopResources;
 import reactor.util.annotation.Nullable;
 
@@ -103,7 +105,7 @@ public final class PostgresqlConnectionConfiguration {
 
     private final Map<String, String> options;
 
-    private final CharSequence password;
+    private final Publisher<CharSequence> password;
 
     private final boolean preferAttachedBuffers;
 
@@ -123,18 +125,18 @@ public final class PostgresqlConnectionConfiguration {
 
     private final TimeZone timeZone;
 
-    private final String username;
+    private final Publisher<String> username;
 
     private PostgresqlConnectionConfiguration(String applicationName, boolean autodetectExtensions, @Nullable boolean compatibilityMode, @Nullable Duration connectTimeout, @Nullable String database,
                                               LogLevel errorResponseLogLevel,
                                               List<Extension> extensions, ToIntFunction<String> fetchSize, boolean forceBinary, @Nullable Duration lockWaitTimeout,
                                               @Nullable LoopResources loopResources,
                                               @Nullable MultiHostConfiguration multiHostConfiguration,
-                                              LogLevel noticeLogLevel, @Nullable Map<String, String> options, @Nullable CharSequence password, boolean preferAttachedBuffers,
+                                              LogLevel noticeLogLevel, @Nullable Map<String, String> options, Publisher<CharSequence> password, boolean preferAttachedBuffers,
                                               int preparedStatementCacheQueries, @Nullable String schema,
                                               @Nullable SingleHostConfiguration singleHostConfiguration, SSLConfig sslConfig, @Nullable Duration statementTimeout,
                                               boolean tcpKeepAlive, boolean tcpNoDelay, TimeZone timeZone,
-                                              String username) {
+                                              Publisher<String> username) {
         this.applicationName = Assert.requireNonNull(applicationName, "applicationName must not be null");
         this.autodetectExtensions = autodetectExtensions;
         this.compatibilityMode = compatibilityMode;
@@ -200,7 +202,7 @@ public String toString() {
             ", multiHostConfiguration='" + this.multiHostConfiguration + '\'' +
             ", noticeLogLevel='" + this.noticeLogLevel + '\'' +
             ", options='" + this.options + '\'' +
-            ", password='" + obfuscate(this.password != null ? this.password.length() : 0) + '\'' +
+            ", password='" + obfuscate(this.password != null ? 4 : 0) + '\'' +
             ", preferAttachedBuffers=" + this.preferAttachedBuffers +
             ", singleHostConfiguration=" + this.singleHostConfiguration +
             ", statementTimeout=" + this.statementTimeout +
@@ -261,8 +263,7 @@ Map<String, String> getOptions() {
         return Collections.unmodifiableMap(this.options);
     }
 
-    @Nullable
-    CharSequence getPassword() {
+    Publisher<CharSequence> getPassword() {
         return this.password;
     }
 
@@ -290,7 +291,7 @@ SingleHostConfiguration getRequiredSingleHostConfiguration() {
         return config;
     }
 
-    String getUsername() {
+    Publisher<String> getUsername() {
         return this.username;
     }
 
@@ -380,7 +381,7 @@ public static final class Builder {
         private Map<String, String> options;
 
         @Nullable
-        private CharSequence password;
+        private Publisher<CharSequence> password;
 
         private boolean preferAttachedBuffers = false;
 
@@ -423,7 +424,7 @@ public static final class Builder {
         private LoopResources loopResources = null;
 
         @Nullable
-        private String username;
+        private Publisher<String> username;
 
         private Builder() {
         }
@@ -743,7 +744,31 @@ public Builder options(Map<String, String> options) {
          * @return this {@link Builder}
          */
         public Builder password(@Nullable CharSequence password) {
-            this.password = password;
+            this.password = Mono.justOrEmpty(password);
+            return this;
+        }
+
+        /**
+         * Configure the password publisher. The publisher is used on each authentication attempt.
+         *
+         * @param password the password
+         * @return this {@link Builder}
+         * @since 1.0.3
+         */
+        public Builder password(Publisher<CharSequence> password) {
+            this.password = Mono.from(password);
+            return this;
+        }
+
+        /**
+         * Configure the password supplier. The supplier is used on each authentication attempt.
+         *
+         * @param password the password
+         * @return this {@link Builder}
+         * @since 1.0.3
+         */
+        public Builder password(Supplier<CharSequence> password) {
+            this.password = Mono.fromSupplier(password);
             return this;
         }
 
@@ -780,7 +805,6 @@ public Builder preferAttachedBuffers(boolean preferAttachedBuffers) {
          *
          * @param preparedStatementCacheQueries the preparedStatementCacheQueries
          * @return this {@link Builder}
-         * @throws IllegalArgumentException if {@code username} is {@code null}
          * @since 0.8.1
          */
         public Builder preparedStatementCacheQueries(int preparedStatementCacheQueries) {
@@ -1023,10 +1047,34 @@ public Builder timeZone(TimeZone timeZone) {
          * @throws IllegalArgumentException if {@code username} is {@code null}
          */
         public Builder username(String username) {
+            this.username = Mono.just(Assert.requireNonNull(username, "username must not be null"));
+            return this;
+        }
+
+        /**
+         * Configure the username publisher. The publisher is used on each authentication attempt.
+         *
+         * @param username the username
+         * @return this {@link Builder}
+         * @throws IllegalArgumentException if {@code username} is {@code null}
+         */
+        public Builder username(Publisher<String> username) {
             this.username = Assert.requireNonNull(username, "username must not be null");
             return this;
         }
 
+        /**
+         * Configure the username supplier. The supplier is used on each authentication attempt.
+         *
+         * @param username the username
+         * @return this {@link Builder}
+         * @throws IllegalArgumentException if {@code username} is {@code null}
+         */
+        public Builder username(Supplier<String> username) {
+            this.username = Mono.fromSupplier(Assert.requireNonNull(username, "username must not be null"));
+            return this;
+        }
+
         @Override
         public String toString() {
             return "Builder{" +
@@ -1044,7 +1092,7 @@ public String toString() {
                 ", multiHostConfiguration='" + this.multiHostConfiguration + '\'' +
                 ", noticeLogLevel='" + this.noticeLogLevel + '\'' +
                 ", parameters='" + this.options + '\'' +
-                ", password='" + obfuscate(this.password != null ? this.password.length() : 0) + '\'' +
+                ", password='" + obfuscate(this.password != null ? 4 : 0) + '\'' +
                 ", preparedStatementCacheQueries='" + this.preparedStatementCacheQueries + '\'' +
                 ", schema='" + this.schema + '\'' +
                 ", singleHostConfiguration='" + this.singleHostConfiguration + '\'' +

src/main/java/io/r2dbc/postgresql/PostgresqlConnectionFactoryProvider.java

@@ -27,6 +27,7 @@
 import io.r2dbc.spi.ConnectionFactoryOptions;
 import io.r2dbc.spi.ConnectionFactoryProvider;
 import io.r2dbc.spi.Option;
+import org.reactivestreams.Publisher;
 import reactor.netty.resources.LoopResources;
 
 import javax.net.ssl.HostnameVerifier;
@@ -37,6 +38,7 @@
 import java.util.Map;
 import java.util.TimeZone;
 import java.util.function.Function;
+import java.util.function.Supplier;
 
 import static io.r2dbc.spi.ConnectionFactoryOptions.CONNECT_TIMEOUT;
 import static io.r2dbc.spi.ConnectionFactoryOptions.DATABASE;
@@ -290,6 +292,7 @@ public boolean supports(ConnectionFactoryOptions connectionFactoryOptions) {
      * @return this {@link PostgresqlConnectionConfiguration.Builder}
      * @throws IllegalArgumentException if {@code options} is {@code null}
      */
+    @SuppressWarnings("unchecked")
     private static PostgresqlConnectionConfiguration.Builder fromConnectionFactoryOptions(ConnectionFactoryOptions options) {
 
         Assert.requireNonNull(options, "connectionFactoryOptions must not be null");
@@ -344,7 +347,6 @@ private static PostgresqlConnectionConfiguration.Builder fromConnectionFactoryOp
         mapper.fromTyped(LOOP_RESOURCES).to(builder::loopResources);
         mapper.from(NOTICE_LOG_LEVEL).map(it -> OptionMapper.toEnum(it, LogLevel.class)).to(builder::noticeLogLevel);
         mapper.from(OPTIONS).map(PostgresqlConnectionFactoryProvider::convertToMap).to(builder::options);
-        mapper.fromTyped(PASSWORD).to(builder::password);
         mapper.from(PORT).map(OptionMapper::toInteger).to(builder::port);
         mapper.from(PREFER_ATTACHED_BUFFERS).map(OptionMapper::toBoolean).to(builder::preferAttachedBuffers);
         mapper.from(PREPARED_STATEMENT_CACHE_QUERIES).map(OptionMapper::toInteger).to(builder::preparedStatementCacheQueries);
@@ -363,7 +365,26 @@ private static PostgresqlConnectionConfiguration.Builder fromConnectionFactoryOp
 
             return TimeZone.getTimeZone(it.toString());
         }).to(builder::timeZone);
-        builder.username("" + options.getRequiredValue(USER));
+
+        Object user = options.getRequiredValue(USER);
+        Object password = options.getValue(PASSWORD);
+
+        if (user instanceof Supplier) {
+            builder.username((Supplier<String>) user);
+        } else if (user instanceof Publisher) {
+            builder.username((Publisher<String>) user);
+        } else {
+            builder.username("" + user);
+        }
+        if (password != null) {
+            if (password instanceof Supplier) {
+                builder.password((Supplier<CharSequence>) password);
+            } else if (password instanceof Publisher) {
+                builder.password((Publisher<CharSequence>) password);
+            } else {
+                builder.password((CharSequence) password);
+            }
+        }
 
         return builder;
     }

src/main/java/io/r2dbc/postgresql/SingleHostConnectionFunction.java

@@ -26,6 +26,7 @@
 import io.r2dbc.postgresql.message.backend.AuthenticationMessage;
 import io.r2dbc.postgresql.util.Assert;
 import reactor.core.publisher.Mono;
+import reactor.util.annotation.Nullable;
 
 import java.net.SocketAddress;
 
@@ -44,26 +45,54 @@ final class SingleHostConnectionFunction implements ConnectionFunction {
     public Mono<Client> connect(SocketAddress endpoint, ConnectionSettings settings) {
 
         return this.upstreamFunction.connect(endpoint, settings)
-            .delayUntil(client -> StartupMessageFlow
-                .exchange(this::getAuthenticationHandler, client, this.configuration.getDatabase(), this.configuration.getUsername(),
-                    getParameterProvider(this.configuration, settings))
+            .delayUntil(client -> getCredentials().flatMapMany(credentials -> StartupMessageFlow
+                    .exchange(auth -> getAuthenticationHandler(auth, credentials), client, this.configuration.getDatabase(), credentials.getUsername(),
+                        getParameterProvider(this.configuration, settings)))
                 .handle(ExceptionFactory.INSTANCE::handleErrorResponse));
     }
 
     private static PostgresStartupParameterProvider getParameterProvider(PostgresqlConnectionConfiguration configuration, ConnectionSettings settings) {
         return new PostgresStartupParameterProvider(configuration.getApplicationName(), configuration.getTimeZone(), settings);
     }
 
-    protected AuthenticationHandler getAuthenticationHandler(AuthenticationMessage message) {
+    protected AuthenticationHandler getAuthenticationHandler(AuthenticationMessage message, UsernameAndPassword usernameAndPassword) {
         if (PasswordAuthenticationHandler.supports(message)) {
-            CharSequence password = Assert.requireNonNull(this.configuration.getPassword(), "Password must not be null");
-            return new PasswordAuthenticationHandler(password, this.configuration.getUsername());
+            CharSequence password = Assert.requireNonNull(usernameAndPassword.getPassword(), "Password must not be null");
+            return new PasswordAuthenticationHandler(password, usernameAndPassword.getUsername());
         } else if (SASLAuthenticationHandler.supports(message)) {
-            CharSequence password = Assert.requireNonNull(this.configuration.getPassword(), "Password must not be null");
-            return new SASLAuthenticationHandler(password, this.configuration.getUsername());
+            CharSequence password = Assert.requireNonNull(usernameAndPassword.getPassword(), "Password must not be null");
+            return new SASLAuthenticationHandler(password, usernameAndPassword.getUsername());
         } else {
             throw new IllegalStateException(String.format("Unable to provide AuthenticationHandler capable of handling %s", message));
         }
     }
 
+    Mono<UsernameAndPassword> getCredentials() {
+
+        return Mono.zip(Mono.from(this.configuration.getUsername()).single(), Mono.from(this.configuration.getPassword()).singleOptional()).map(it -> {
+            return new UsernameAndPassword(it.getT1(), it.getT2().orElse(null));
+        });
+    }
+
+    static class UsernameAndPassword {
+
+        final String username;
+
+        final @Nullable CharSequence password;
+
+        public UsernameAndPassword(String username, @Nullable CharSequence password) {
+            this.username = username;
+            this.password = password;
+        }
+
+        public String getUsername() {
+            return this.username;
+        }
+
+        @Nullable
+        public CharSequence getPassword() {
+            return this.password;
+        }
+    }
+
 }

src/test/java/io/r2dbc/postgresql/PostgresqlConnectionConfigurationUnitTests.java

@@ -53,7 +53,7 @@ void builderHostAndSocket() {
 
     @Test
     void builderNoUsername() {
-        assertThatIllegalArgumentException().isThrownBy(() -> PostgresqlConnectionConfiguration.builder().username(null))
+        assertThatIllegalArgumentException().isThrownBy(() -> PostgresqlConnectionConfiguration.builder().username((String) null))
             .withMessage("username must not be null");
     }
 
@@ -84,9 +84,7 @@ void configuration() {
             .hasFieldOrPropertyWithValue("database", "test-database")
             .hasFieldOrPropertyWithValue("singleHostConfiguration.host", "test-host")
             .hasFieldOrProperty("options")
-            .hasFieldOrPropertyWithValue("password", null)
             .hasFieldOrPropertyWithValue("singleHostConfiguration.port", 100)
-            .hasFieldOrPropertyWithValue("username", "test-username")
             .hasFieldOrProperty("sslConfig")
             .hasFieldOrPropertyWithValue("tcpKeepAlive", true)
             .hasFieldOrPropertyWithValue("tcpNoDelay", false)
@@ -116,9 +114,7 @@ void configureStatementAndLockTimeouts() {
             .hasFieldOrPropertyWithValue("database", "test-database")
             .hasFieldOrPropertyWithValue("singleHostConfiguration.host", "test-host")
             .hasFieldOrProperty("options")
-            .hasFieldOrPropertyWithValue("password", null)
             .hasFieldOrPropertyWithValue("singleHostConfiguration.port", 100)
-            .hasFieldOrPropertyWithValue("username", "test-username")
             .hasFieldOrProperty("sslConfig")
             .hasFieldOrPropertyWithValue("tcpKeepAlive", true)
             .hasFieldOrPropertyWithValue("tcpNoDelay", false)
@@ -160,10 +156,8 @@ void configurationDefaults() {
             .hasFieldOrPropertyWithValue("applicationName", "r2dbc-postgresql")
             .hasFieldOrPropertyWithValue("database", "test-database")
             .hasFieldOrPropertyWithValue("singleHostConfiguration.host", "test-host")
-            .hasFieldOrPropertyWithValue("password", "test-password")
             .hasFieldOrPropertyWithValue("singleHostConfiguration.port", 5432)
             .hasFieldOrProperty("options")
-            .hasFieldOrPropertyWithValue("username", "test-username")
             .hasFieldOrProperty("sslConfig")
             .hasFieldOrPropertyWithValue("tcpKeepAlive", false)
             .hasFieldOrPropertyWithValue("tcpNoDelay", true)

src/test/java/io/r2dbc/postgresql/PostgresqlConnectionFactoryProviderUnitTests.java

@@ -25,6 +25,8 @@
 import io.r2dbc.spi.ConnectionFactoryOptions;
 import io.r2dbc.spi.Option;
 import org.junit.jupiter.api.Test;
+import reactor.core.publisher.Mono;
+import reactor.test.StepVerifier;
 
 import java.time.Duration;
 import java.util.Arrays;
@@ -33,6 +35,7 @@
 import java.util.Map;
 import java.util.Objects;
 import java.util.TimeZone;
+import java.util.function.Supplier;
 
 import static io.r2dbc.postgresql.PostgresqlConnectionFactoryProvider.AUTODETECT_EXTENSIONS;
 import static io.r2dbc.postgresql.PostgresqlConnectionFactoryProvider.COMPATIBILITY_MODE;
@@ -617,6 +620,34 @@ void shouldConfigureExtensions() {
         assertThat(factory.getConfiguration().getExtensions()).containsExactly(testExtension1, testExtension2);
     }
 
+    @Test
+    void supportsUsernameAndPasswordSupplier() {
+        PostgresqlConnectionFactory factory = this.provider.create(builder()
+            .option(DRIVER, LEGACY_POSTGRESQL_DRIVER)
+            .option(HOST, "test-host")
+            .option(Option.valueOf("password"), (Supplier<String>) () -> "test-password")
+            .option(Option.valueOf("user"), (Supplier<String>) () -> "test-user")
+            .option(USER, "test-user")
+            .build());
+
+        StepVerifier.create(factory.getConfiguration().getPassword()).expectNext("test-password").verifyComplete();
+        StepVerifier.create(factory.getConfiguration().getUsername()).expectNext("test-user").verifyComplete();
+    }
+
+    @Test
+    void supportsUsernameAndPasswordPublisher() {
+        PostgresqlConnectionFactory factory = this.provider.create(builder()
+            .option(DRIVER, LEGACY_POSTGRESQL_DRIVER)
+            .option(HOST, "test-host")
+            .option(Option.valueOf("password"), Mono.just("test-password"))
+            .option(Option.valueOf("user"), Mono.just("test-user"))
+            .option(USER, "test-user")
+            .build());
+
+        StepVerifier.create(factory.getConfiguration().getPassword()).expectNext("test-password").verifyComplete();
+        StepVerifier.create(factory.getConfiguration().getUsername()).expectNext("test-user").verifyComplete();
+    }
+
     private static class TestExtension implements Extension {
 
         private final String name;