Allow running --open with --all (#660)

This allows you to `--open` the docs built with `--all`. This should be
useful when testing changes that effect all docs, like the redirect work
that I plan on doing soon.

There is a wrinkle though: to make serving the docs locally work we
actually built *different* docs. We'd switch from finding jQuery at
`/static/js/jquery.min.js` to getting it from
`https://www.elastic.co/static/js/jquery.min.js`. This worked, and it
was simple enough to do for the built in python web server that we use
when you run `--open` outside of docker, but we don't want to do that
when we serve all of the docs because most of the docs will have been
built with the standard template.

But now that we have docker we don't have to! In docker we're using
nginx to serve the docs and we can write a few rewrite rules to fix the
missing assets. For good measure we assets rewrite when we're running in
docker even when we're building a single doc. So now building a single
doc is just that much more real!

Author: nik9000

build_docs.pl

@@ -80,7 +80,7 @@ BEGIN
     %$template_urls,
     lenient  => $Opts->{lenient},
     force    => $Opts->{reload_template},
-    abs_urls => $Opts->{doc}
+    abs_urls => ! $running_in_standard_docker && $Opts->{doc},
 );
 
 $Opts->{doc}       ? build_local( $Opts->{doc} )
@@ -124,72 +124,8 @@ sub build_local {
     my $html = $dir->file('index.html');
 
     if ( $Opts->{open} ) {
-        if ( my $pid = fork ) {
-            # parent
-            $SIG{INT} = sub {
-                kill -9, $pid;
-            };
-            if ( $Opts->{open} && not $running_in_standard_docker ) {
-                sleep 1;
-                say "Opening: " . $html;
-                say "Press Ctrl-C to exit the web server";
-                open_browser('http://localhost:8000/index.html');
-            }
-
-            wait;
-            say "\nExiting";
-            exit;
-        }
-        else {
-            if ( $running_in_standard_docker ) {
-                # We use nginx to serve files instead of the python built in web server
-                # when we're running inside docker because the python web server performs
-                # badly there. nginx is fine.
-                open(my $nginx_conf, '>', '/tmp/docs.conf') or dir("Couldn't write nginx conf to /tmp/docs/.conf");
-                print $nginx_conf <<"CONF";
-daemon off;
-error_log /dev/stdout info;
-pid /run/nginx/nginx.pid;
-
-events {
-  worker_connections 64;
-}
-
-http {
-  error_log /dev/stdout crit;
-  log_format short '[\$time_local] "\$request" \$status';
-  access_log /dev/stdout short;
-  server {
-    listen 8000;
-    location / {
-      root $dir;
-      add_header 'Access-Control-Allow-Origin' '*';
-      if (\$request_method = 'OPTIONS') {
-        add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS';
-        add_header 'Access-Control-Allow-Headers' 'kbn-xsrf-token';
-      }
-    }
-    types {
-      text/html  html;
-      application/javascript  js;
-      text/css   css;
-    }
-  }
-}
-CONF
-                close $nginx_conf;
-                close STDIN;
-                open( STDIN, "</dev/null" );
-                chdir $dir;
-                exec( 'nginx', '-c', '/tmp/docs.conf' );
-            } else {
-                my $http = dir( 'resources', 'http.py' )->absolute;
-                close STDIN;
-                open( STDIN, "</dev/null" );
-                chdir $dir;
-                exec( $http '8000' );
-            }
-        }
+        say "Opening: " . $html;
+        serve_and_open_browser( $dir, 'index.html' );
     }
     else {
         say "See: $html";
@@ -282,6 +218,7 @@ sub build_all {
         check_links($build_dir);
     }
     push_changes($build_dir, $target_repo, $target_repo_checkout) if $Opts->{push};
+    serve_and_open_browser( $build_dir, '/' ) if $Opts->{open};
 
     $temp_dir->rmtree;
 }
@@ -733,6 +670,82 @@ sub pick_conf {
     die $Opts->{conf} . " doesn't exist";
 }
 
+#===================================
+sub serve_and_open_browser {
+#===================================
+    my ( $dir, $open_path ) = @_;
+
+    if ( my $pid = fork ) {
+        # parent
+        $SIG{INT} = sub {
+            kill -9, $pid;
+        };
+        if ( not $running_in_standard_docker ) {
+            sleep 1;
+            say "Press Ctrl-C to exit the web server";
+            open_browser("http://localhost:8000/$open_path");
+        }
+
+        wait;
+        say "\nExiting";
+        exit;
+    }
+    else {
+        if ( $running_in_standard_docker ) {
+            # We use nginx to serve files instead of the python built in web server
+            # when we're running inside docker because the python web server performs
+            # badly there. nginx is fine.
+            open(my $nginx_conf, '>', '/tmp/docs.conf') or dir("Couldn't write nginx conf to /tmp/docs/.conf");
+            print $nginx_conf <<"CONF";
+daemon off;
+error_log /dev/stdout info;
+pid /run/nginx/nginx.pid;
+
+events {
+  worker_connections 64;
+}
+
+http {
+  error_log /dev/stdout crit;
+  log_format short '[\$time_local] "\$request" \$status';
+  access_log /dev/stdout short;
+  server {
+    listen 8000;
+    location / {
+      root $dir;
+      add_header 'Access-Control-Allow-Origin' '*';
+      if (\$request_method = 'OPTIONS') {
+        add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS';
+        add_header 'Access-Control-Allow-Headers' 'kbn-xsrf-token';
+      }
+    }
+    types {
+      text/html  html;
+      application/javascript  js;
+      text/css   css;
+    }
+    rewrite ^/android-chrome-(.+)\$ https://www.elastic.co/android-chrome-\$1 permanent;
+    rewrite ^/assets/(.+)\$ https://www.elastic.co/assets/\$1 permanent;
+    rewrite ^/favicon(.+)\$ https://www.elastic.co/favicon\$1 permanent;
+    rewrite ^/gdpr-data\$ https://www.elastic.co/gdpr-data permanent;
+    rewrite ^/static/(.+)\$ https://www.elastic.co/static/\$1 permanent;
+  }
+}
+CONF
+            close $nginx_conf;
+            close STDIN;
+            open( STDIN, "</dev/null" );
+            exec( 'nginx', '-c', '/tmp/docs.conf' );
+        } else {
+            my $http = dir( 'resources', 'http.py' )->absolute;
+            close STDIN;
+            open( STDIN, "</dev/null" );
+            chdir $dir;
+            exec( $http '8000' );
+        }
+    }
+}
+
 #===================================
 sub usage {
 #===================================
@@ -750,7 +763,6 @@ sub usage {
           --toc             Include a TOC at the beginning of the page.
           --out dest/dir/   Defaults to ./html_docs.
           --chunk 1         Also chunk sections into separate files
-          --open            Open the docs in a browser once built.
           --lenient         Ignore linking errors
           --lang            Defaults to 'en'
           --resource        Path to image dir - may be repeated
@@ -780,6 +792,7 @@ sub usage {
           --in_standard_docker
                             Specified by build_docs when running in its container
           --conf <ymlfile>  Use your own configuration file, defaults to the bundled conf.yaml
+          --open            Open the docs in a browser once built.
 
 USAGE
     if ( $Opts->{in_standard_docker} ) {