[ONOS-7732] Automating switch workflow: ofoverlay(Openflow overlay) workflow

Change-Id: I162a93465267547b3056f9096743b699aa4416b9
diff --git a/apps/workflow/ofoverlay/app/src/main/java/org/onosproject/ofoverlay/impl/util/SshUtil.java b/apps/workflow/ofoverlay/app/src/main/java/org/onosproject/ofoverlay/impl/util/SshUtil.java
new file mode 100644
index 0000000..0c6caff
--- /dev/null
+++ b/apps/workflow/ofoverlay/app/src/main/java/org/onosproject/ofoverlay/impl/util/SshUtil.java
@@ -0,0 +1,366 @@
+/*
+ * Copyright 2019-present Open Networking Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.ofoverlay.impl.util;
+
+import com.google.common.io.CharStreams;
+import com.jcraft.jsch.Channel;
+import com.jcraft.jsch.ChannelExec;
+import com.jcraft.jsch.JSch;
+import com.jcraft.jsch.JSchException;
+import com.jcraft.jsch.Session;
+import org.onlab.packet.IpAddress;
+import org.onosproject.workflow.api.WorkflowException;
+import org.onosproject.workflow.model.accessinfo.SshAccessInfo;
+import org.slf4j.Logger;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.nio.charset.StandardCharsets;
+import java.util.Collections;
+import java.util.Set;
+import java.util.regex.Pattern;
+import java.util.stream.Collectors;
+
+import static org.onosproject.workflow.api.CheckCondition.check;
+import static org.slf4j.LoggerFactory.getLogger;
+
+/**
+ * Class for SSH utilities.
+ */
+public final class SshUtil {
+
+    protected static final Logger log = getLogger(SshUtil.class);
+
+    private static final String STRICT_HOST_CHECKING = "StrictHostKeyChecking";
+    private static final String DEFAULT_STRICT_HOST_CHECKING = "no";
+    private static final int DEFAULT_SESSION_TIMEOUT = 30000; // milliseconds
+
+    private static final String SPACESEPERATOR = " ";
+
+    /**
+     * Default constructor.
+     */
+    private SshUtil() {
+    }
+
+    /**
+     * Creates a new session with a given ssh access information.
+     *
+     * @param sshInfo information to ssh to the remote server
+     * @return ssh session, or null
+     */
+    public static Session connect(SshAccessInfo sshInfo) {
+        Session session;
+
+        try {
+            JSch jsch = new JSch();
+            jsch.addIdentity(sshInfo.privateKey());
+
+            session = jsch.getSession(sshInfo.user(),
+                    sshInfo.remoteIp().toString(),
+                    sshInfo.port().toInt());
+            session.setConfig(STRICT_HOST_CHECKING, DEFAULT_STRICT_HOST_CHECKING);
+            session.connect(DEFAULT_SESSION_TIMEOUT);
+
+        } catch (JSchException e) {
+            log.warn("Failed to connect to {}", sshInfo.toString(), e);
+            session = authUserPwd(sshInfo);
+        }
+        return session;
+    }
+
+    /**
+     * Creates a new session with ssh access info.
+     *
+     * @param sshInfo information to ssh to the remote server
+     * @return ssh session, or null
+     */
+    public static Session authUserPwd(SshAccessInfo sshInfo) {
+        log.info("Retrying Session with {}", sshInfo);
+        try {
+            JSch jsch = new JSch();
+
+            Session session = jsch.getSession(sshInfo.user(),
+                    sshInfo.remoteIp().toString(),
+                    sshInfo.port().toInt());
+            session.setPassword(sshInfo.password());
+            session.setConfig(STRICT_HOST_CHECKING, DEFAULT_STRICT_HOST_CHECKING);
+            session.connect(DEFAULT_SESSION_TIMEOUT);
+
+            return session;
+        } catch (JSchException e) {
+            log.warn("Failed to connect to {} due to {}", sshInfo.toString(), e);
+            return null;
+        }
+    }
+
+    /**
+     * Closes a connection.
+     *
+     * @param session session ssh session
+     */
+    public static void disconnect(Session session) {
+        if (session.isConnected()) {
+            session.disconnect();
+        }
+    }
+
+    /**
+     * Fetches last term after executing command.
+     * @param session  ssh session
+     * @param command command to execute
+     * @return last term, or null
+     */
+    public static String fetchLastTerm(Session session, String command) {
+         if (session == null || !session.isConnected()) {
+             log.error("Invalid session({})", session);
+             return null;
+         }
+
+         log.info("fetchLastTerm: ssh command {} to {}", command, session.getHost());
+
+         try {
+             Channel channel = session.openChannel("exec");
+             if (channel == null) {
+                 log.error("Invalid channel of session({}) for command({})", session, command);
+                 return null;
+             }
+
+             ((ChannelExec) channel).setCommand(command);
+             channel.setInputStream(null);
+             InputStream output = channel.getInputStream();
+             channel.connect();
+             String[] lineList = null;
+
+             try (BufferedReader reader = new BufferedReader(new InputStreamReader(output, StandardCharsets.UTF_8))) {
+                 lineList = reader.lines().findFirst().get().split(SPACESEPERATOR);
+             } catch (IOException e) {
+                 log.error("Exception in fetchLastTerm", e);
+             } finally {
+                 channel.disconnect();
+                 output.close();
+             }
+
+             if (lineList.length > 0) {
+                 return lineList[lineList.length - 1];
+             } else {
+                 return null;
+             }
+
+         } catch (JSchException | IOException e) {
+             log.error("Exception in fetchLastTerm", e);
+             return null;
+         }
+    }
+
+    /**
+     * Executes a given command. It opens exec channel for the command and closes
+     * the channel when it's done.
+     *
+     * @param session ssh connection to a remote server
+     * @param command command to execute
+     * @return command output string if the command succeeds, or null
+     */
+    public static String executeCommand(Session session, String command) {
+        if (session == null || !session.isConnected()) {
+            log.error("Invalid session({})", session);
+            return null;
+        }
+
+        log.info("executeCommand: ssh command {} to {}", command, session.getHost());
+
+        try {
+            Channel channel = session.openChannel("exec");
+
+            if (channel == null) {
+                log.debug("Invalid channel of session({}) for command({})", session, command);
+                return null;
+            }
+
+            ((ChannelExec) channel).setCommand(command);
+            channel.setInputStream(null);
+            InputStream output = channel.getInputStream();
+
+            channel.connect();
+            String result = CharStreams.toString(new InputStreamReader(output, StandardCharsets.UTF_8));
+            log.trace("SSH result(on {}): {}", session.getHost(), result);
+            channel.disconnect();
+
+            return result;
+        } catch (JSchException | IOException e) {
+            log.debug("Failed to execute command {} due to {}", command, e);
+            return null;
+        }
+    }
+
+    /**
+     * Fetches OVS version information.
+     * @param session Jsch session
+     * @return OVS version
+     * @throws WorkflowException workflow exception
+     */
+    public static OvsVersion fetchOvsVersion(Session session) throws WorkflowException {
+
+        OvsVersion devOvsVersion;
+
+        String ovsVersionStr = fetchLastTerm(session, "ovs-vswitchd --version");
+        if (ovsVersionStr == null) {
+            log.error("Failed to get ovs Version String for ssh session:{}", session);
+            throw new WorkflowException("Failed to get ovs Version String");
+        }
+
+        devOvsVersion = OvsVersion.build(ovsVersionStr);
+        if (devOvsVersion == null) {
+            log.error("Failed to build OVS version for {}", ovsVersionStr);
+            throw new WorkflowException("Failed to build OVS version");
+        }
+
+        return devOvsVersion;
+    }
+
+    private static final String IP_PATTERN = "^([01]?\\d\\d?|2[0-4]\\d|25[0-5])\\." +
+            "([01]?\\d\\d?|2[0-4]\\d|25[0-5])\\." +
+            "([01]?\\d\\d?|2[0-4]\\d|25[0-5])\\." +
+            "([01]?\\d\\d?|2[0-4]\\d|25[0-5])$";
+
+    private static boolean isIPv6(String address) {
+        boolean isCorrect = true;
+        try {
+            IpAddress.valueOf(address);
+        } catch (IllegalArgumentException e) {
+            log.debug("Exception Occurred {}", e.toString());
+            isCorrect = false;
+        }
+        return isCorrect;
+    }
+
+    private static boolean isCidr(String s) {
+        String[] splits = s.split("/");
+        return splits.length == 2 &&
+                (splits[0].matches(IP_PATTERN) || isIPv6(splits[0]));
+    }
+
+    /**
+     * Adds IP address on the interface.
+     * @param session SSH session
+     * @param ifname interface name
+     * @param address network address
+     * @throws WorkflowException workflow exception
+     */
+    public static void addIpAddrOnInterface(Session session, String ifname, NetworkAddress address)
+            throws WorkflowException {
+
+        executeCommand(session, String.format("ip addr add %s dev %s", address.cidr(), ifname));
+
+        Set<NetworkAddress> result = getIpAddrOfInterface(session, ifname);
+        if (!result.contains(address)) {
+            throw new WorkflowException("Failed to set ip(" + address + ") on " + ifname + ",  result: " + result);
+        }
+    }
+
+    /**
+     * Gets IP addresses of interface.
+     * @param session SSH session
+     * @param ifname interface name
+     * @return IP addresses of interface
+     */
+    public static Set<NetworkAddress> getIpAddrOfInterface(Session session, String ifname) {
+
+        String output = executeCommand(session, String.format("ip addr show %s", ifname));
+
+        if (output == null) {
+            return Collections.emptySet();
+        }
+
+        Set<NetworkAddress> result = Pattern.compile(" ")
+                .splitAsStream(output)
+                .filter(SshUtil::isCidr)
+                .map(NetworkAddress::valueOf)
+                .collect(Collectors.toSet());
+        return result;
+    }
+
+    /**
+     * Returns whether the interface has IP address.
+     * @param session SSH session
+     * @param ifname interface name
+     * @param addr network address
+     * @return whether the interface has IP address
+     */
+    public static boolean hasIpAddrOnInterface(Session session, String ifname, NetworkAddress addr) {
+
+        Set<NetworkAddress> phyBrIps = getIpAddrOfInterface(session, ifname);
+
+        return phyBrIps.stream()
+                .anyMatch(ip -> addr.ip().equals(ip.ip()));
+    }
+
+    /**
+     * Sets IP link UP on the interface.
+     * @param session SSH session
+     * @param ifname interface name
+     * @throws WorkflowException workflow exception
+     */
+    public static void setIpLinkUpOnInterface(Session session, String ifname)
+            throws WorkflowException {
+
+        executeCommand(session, String.format("ip link set %s up", ifname));
+
+        if (!isIpLinkUpOnInterface(session, ifname)) {
+            throw new WorkflowException("Failed to set UP on " + ifname);
+        }
+    }
+
+    /**
+     * Returns whether the link of the interface is up.
+     * @param session SSH session
+     * @param ifname interface name
+     * @return whether the link of the interface is up
+     */
+    public static boolean isIpLinkUpOnInterface(Session session, String ifname) {
+        String output = executeCommand(session, String.format("ip link show %s", ifname));
+
+        return output != null && output.contains("UP");
+    }
+
+    /**
+     * Executes SSH behavior.
+     * @param sshAccessInfo SSH Access information
+     * @param behavior SSH behavior
+     * @param <R> Return type of SSH behavior
+     * @return return of SSH behavior
+     * @throws WorkflowException workflow exception
+     */
+    public static <R> R exec(SshAccessInfo sshAccessInfo, SshBehavior<R> behavior)
+            throws WorkflowException {
+
+        check(sshAccessInfo != null, "Invalid sshAccessInfo");
+        Session session = connect(sshAccessInfo);
+        if (session == null || !session.isConnected()) {
+            log.error("Failed to get session for ssh:{}", sshAccessInfo);
+            throw new WorkflowException("Failed to get session for ssh:" + sshAccessInfo);
+        }
+
+        try {
+            return behavior.apply(session);
+        } finally {
+            disconnect(session);
+        }
+    }
+
+}