Add ability to overwrite DNS when trying to contact the related homeserver

application.example.yaml

@@ -339,3 +339,20 @@ invite.sender.email.email: "matrix-identity@example.org"
 #  - /var/lib/mxisd/mxisd.db
 #
 storage.provider.sqlite.database: '/path/to/mxisd.db'
+
+
+######################
+# DNS-related config #
+######################
+# The domain to overwrite
+#
+#dns.overwrite.homeserver.name: 'example.org'
+
+# - 'env' from environment variable specified by value
+# - any other value will use the value as-is as host
+#
+#dns.overwrite.homeserver.type: 'raw'
+
+# The value to use, depending on the type
+#
+#dns.overwrite.homeserver.value: 'localhost:8448'

src/main/groovy/io/kamax/mxisd/config/DnsOverwrite.java

@@ -0,0 +1,52 @@
+/*
+ * mxisd - Matrix Identity Server Daemon
+ * Copyright (C) 2017 Maxime Dor
+ *
+ * https://max.kamax.io/
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package io.kamax.mxisd.config;
+
+import org.apache.commons.lang.StringUtils;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.context.properties.ConfigurationProperties;
+import org.springframework.context.annotation.Configuration;
+
+import java.util.Optional;
+
+@Configuration
+@ConfigurationProperties("dns.overwrite")
+public class DnsOverwrite {
+
+    private Logger log = LoggerFactory.getLogger(DnsOverwrite.class);
+
+    @Autowired
+    private ServerConfig srvCfg;
+
+    @Autowired
+    private DnsOverwriteEntry homeserver;
+
+    public Optional<DnsOverwriteEntry> findHost(String lookup) {
+        if (homeserver != null && StringUtils.equalsIgnoreCase(lookup, homeserver.getName())) {
+            return Optional.of(homeserver);
+        }
+
+        return Optional.empty();
+    }
+
+}

src/main/groovy/io/kamax/mxisd/config/DnsOverwriteEntry.java

@@ -0,0 +1,67 @@
+/*
+ * mxisd - Matrix Identity Server Daemon
+ * Copyright (C) 2017 Maxime Dor
+ *
+ * https://max.kamax.io/
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package io.kamax.mxisd.config;
+
+import org.apache.commons.lang.StringUtils;
+import org.springframework.boot.context.properties.ConfigurationProperties;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+@ConfigurationProperties("dns.overwrite.homeserver")
+public class DnsOverwriteEntry {
+
+    private String name;
+    private String type;
+    private String value;
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getType() {
+        return type;
+    }
+
+    public void setType(String type) {
+        this.type = type;
+    }
+
+    public String getValue() {
+        return value;
+    }
+
+    public void setValue(String value) {
+        this.value = value;
+    }
+
+    public String getTarget() {
+        if (StringUtils.equals("env", getType())) {
+            return System.getenv(getValue());
+        } else {
+            return getValue();
+        }
+    }
+
+}

src/main/groovy/io/kamax/mxisd/invitation/InvitationManager.java

@@ -22,6 +22,8 @@ package io.kamax.mxisd.invitation;
 
 import com.google.gson.Gson;
 import io.kamax.matrix.MatrixID;
+import io.kamax.mxisd.config.DnsOverwrite;
+import io.kamax.mxisd.config.DnsOverwriteEntry;
 import io.kamax.mxisd.exception.BadRequestException;
 import io.kamax.mxisd.exception.MappingAlreadyExistsException;
 import io.kamax.mxisd.invitation.sender.IInviteSender;
@@ -78,6 +80,9 @@ public class InvitationManager {
     @Autowired
     private SignatureManager signMgr;
 
+    @Autowired
+    private DnsOverwrite dns;
+
     private Map<String, IInviteSender> senders;
 
     private CloseableHttpClient client;
@@ -149,6 +154,13 @@ public class InvitationManager {
     // TODO use caching mechanism
     // TODO export in matrix-java-sdk
     String findHomeserverForDomain(String domain) {
+        Optional<DnsOverwriteEntry> entryOpt = dns.findHost(domain);
+        if (entryOpt.isPresent()) {
+            DnsOverwriteEntry entry = entryOpt.get();
+            log.info("Found DNS overwrite for {} to {}", entry.getName(), entry.getTarget());
+            return "https://" + entry.getTarget();
+        }
+
         log.debug("Performing SRV lookup for {}", domain);
         String lookupDns = getSrvRecordName(domain);
         log.info("Lookup name: {}", lookupDns);