add vespaHostname function

4 files changed, 65 insertions, 2 deletions

diff --git a/defaults/src/apps/printdefault/printdefault.cpp b/defaults/src/apps/printdefault/printdefault.cpp
index da0c6782d31..73e199fb441 100644
--- a/defaults/src/apps/printdefault/printdefault.cpp
+++ b/defaults/src/apps/printdefault/printdefault.cpp
@@ -7,13 +7,17 @@
 int main(int argc, char **argv) {
     if (argc != 2) {
         fprintf(stderr, "usage: %s <variable>\n", argv[0]);
-        fprintf(stderr, "  the variable must be 'home' or 'portbase' currently\n");
+        fprintf(stderr, "  variable names are: home, user, hostname, portbase, configservers,\n");
+        fprintf(stderr, "                      configserver_rpc_port, configservers_rpc\n");
+        fprintf(stderr, "                      configservers_http, configsources, configproxy_rpc\n");
         return 1;
     }
     if (strcmp(argv[1], "home") == 0) {
         printf("%s\n", vespa::Defaults::vespaHome());
     } else if (strcmp(argv[1], "user") == 0) {
         printf("%s\n", vespa::Defaults::vespaUser());
+    } else if (strcmp(argv[1], "hostname") == 0) {
+        printf("%s\n", vespa::Defaults::vespaHostname());
     } else if (strcmp(argv[1], "portbase") == 0) {
         printf("%d\n", vespa::Defaults::vespaPortBase());
     } else if (strcmp(argv[1], "configserver_rpc_port") == 0) {
diff --git a/defaults/src/main/java/com/yahoo/vespa/defaults/Defaults.java b/defaults/src/main/java/com/yahoo/vespa/defaults/Defaults.java
index d8cf0947ef0..8a9be7891ae 100644
--- a/defaults/src/main/java/com/yahoo/vespa/defaults/Defaults.java
+++ b/defaults/src/main/java/com/yahoo/vespa/defaults/Defaults.java
@@ -1,8 +1,14 @@
 // Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.defaults;
 
-import java.util.Optional;
+import java.io.BufferedReader;
+import java.io.InputStreamReader;
+import java.net.InetAddress;
+import java.nio.charset.StandardCharsets;
 import java.util.logging.Logger;
+import java.util.Optional;
+
+
 
 /**
  * The defaults of basic Vespa configuration variables.
@@ -18,12 +24,14 @@ public class Defaults {
 
     private final String vespaHome;
     private final String vespaUser;
+    private final String vespaHost;
     private final int vespaWebServicePort;
     private final int vespaPortBase;
 
     private Defaults() {
         vespaHome = findVespaHome();
         vespaUser = findVespaUser();
+        vespaHost = findVespaHostname();
         vespaWebServicePort = findVespaWebServicePort();
         vespaPortBase = 19000; // TODO
     }
@@ -42,6 +50,23 @@ public class Defaults {
         return vespaHome;
     }
 
+    static private String findVespaHostname() {
+        Optional<String> vespaHostEnv = Optional.ofNullable(System.getenv("VESPA_HOSTNAME"));
+        if (vespaHostEnv.isPresent() && ! vespaHostEnv.get().trim().isEmpty()) {
+            return vespaHostEnv.get().trim();
+        }
+        try {
+            Process p = Runtime.getRuntime().exec("hostname");
+            BufferedReader r = new BufferedReader(
+                    new InputStreamReader(p.getInputStream(), StandardCharsets.UTF_8));
+            String line = r.readLine();
+            if (line != null && ! line.trim().isEmpty()) {
+                return line;
+            }
+        } catch (java.io.IOException e) {}
+        return "localhost";
+    }
+
     static private String findVespaUser() {
         Optional<String> vespaUserEnv = Optional.ofNullable(System.getenv("VESPA_USER"));
         if (! vespaUserEnv.isPresent()) {
@@ -72,6 +97,13 @@ public class Defaults {
      **/
     public String vespaUser() { return vespaUser; }
 
+
+    /**
+     * Compute the host name that identifies myself
+     * @return the vespa host name
+     **/
+    public String vespaHostname() { return vespaHost; }
+
     /**
      * Returns the path to the root under which Vespa should read and write files.
      * Will not end with a "/".
diff --git a/defaults/src/vespa/defaults.cpp b/defaults/src/vespa/defaults.cpp
index 730ec4735ca..d10e4064f83 100644
--- a/defaults/src/vespa/defaults.cpp
+++ b/defaults/src/vespa/defaults.cpp
@@ -13,8 +13,12 @@
 
 namespace {
 
+#define HOST_BUF_SZ 1024
+
 const char *defaultHome = "/opt/vespa";
 const char *defaultUser = "vespa";
+const char *defaultHost = "localhost";
+char hostbuf[HOST_BUF_SZ];
 int defaultWebServicePort = 8080;
 int defaultPortBase = 19000;
 int defaultPortConfigServerRpc = 19070;
@@ -63,6 +67,16 @@ void findDefaults() {
             defaultUser = env;
         }
     }
+    env = getenv("VESPA_HOSTNAME");
+    if (env != NULL) {
+        defaultHost = env;
+    } else {
+        int err = gethostname(hostbuf, HOST_BUF_SZ);
+        hostbuf[HOST_BUF_SZ-1] = '\0';
+        if (err == 0 && strlen(hostbuf) > 0 && strlen(hostbuf) < HOST_BUF_SZ-1) {
+            defaultHost = hostbuf;
+        }
+    }
     long p = getNumFromEnv("VESPA_WEB_SERVICE_PORT");
     if (p > 0) {
         // fprintf(stderr, "debug\tdefault web service port is '%ld'\n", p);
@@ -180,6 +194,13 @@ Defaults::vespaUser()
     return defaultUser;
 }
 
+const char *
+Defaults::vespaHostname()
+{
+    findDefaults();
+    return defaultHost;
+}
+
 int
 Defaults::vespaWebServicePort()
 {
diff --git a/defaults/src/vespa/defaults.h b/defaults/src/vespa/defaults.h
index 53e44b3f526..d0b400ef563 100644
--- a/defaults/src/vespa/defaults.h
+++ b/defaults/src/vespa/defaults.h
@@ -34,6 +34,12 @@ public:
     static const char *vespaUser();
 
     /**
+     * Compute the host name that identifies myself
+     * @return the vespa host name
+     **/
+    static const char *vespaHostname();
+
+    /**
      * Compute the port number where the Vespa webservice
      * container should be available.
      *