[PATCH server-haj002 v1 3/6] mastodon: Fix DNS resolution error

[Alviro Iskandar Setiawan <alviro.iskandar@gnuweeb.org>]

The default DNS system is not properly configured in this environment
and it leads to DNS resolution error. Provide custom resolv.conf file
and hosts file to satisfy the need of mastodon container.

The custom resolv.conf script will use the host IP address as the DNS
server. Therefore, the host must provide a working DNS server. It can
simply be done by adding these two lines to /etc/systemd/resolved.conf

   DNSStubListenerExtra=0.0.0.0:53
   DNSStubListenerExtra=[::]:53

Signed-off-by: Alviro Iskandar Setiawan <alviro.iskandar@gnuweeb.org>
---
 mastodon/docker-compose.example.yml | 2 ++
 mastodon/hosts                      | 8 ++++++++
 mastodon/resolv.conf                | 3 +++
 3 files changed, 13 insertions(+)
 create mode 100644 mastodon/hosts
 create mode 100644 mastodon/resolv.conf

diff --git a/mastodon/docker-compose.example.yml b/mastodon/docker-compose.example.yml
index e695b0a..769800f 100644
--- a/mastodon/docker-compose.example.yml
+++ b/mastodon/docker-compose.example.yml
@@ -94,3 +94,5 @@ services:
       - DB_POOL=5 #optional
     volumes:
       - /opt/mastodon/mastodon/config:/config
+      - ./resolv.conf:/etc/resolv.conf
+      - ./hosts:/etc/hosts
diff --git a/mastodon/hosts b/mastodon/hosts
new file mode 100644
index 0000000..23c9d56
--- /dev/null
+++ b/mastodon/hosts
@@ -0,0 +1,8 @@
+127.0.0.1	localhost
+::1		localhost ip6-localhost ip6-loopback
+fe00::0		ip6-localnet
+ff00::0		ip6-mcastprefix
+ff02::1		ip6-allnodes
+ff02::2		ip6-allrouters
+10.4.4.2	social social.gnuweeb.org
+51.81.211.47	mail1.gnuweeb.org
diff --git a/mastodon/resolv.conf b/mastodon/resolv.conf
new file mode 100644
index 0000000..2adb825
--- /dev/null
+++ b/mastodon/resolv.conf
@@ -0,0 +1,3 @@
+nameserver 10.4.4.1
+nameserver 8.8.8.8
+nameserver 8.8.4.4
-- 
Alviro Iskandar Setiawan