From: Paul Suh <plsuh@goodeast.com>
To: Banibrata Dutta <banibrata.dutta@gmail.com>
CC: "~alpine/users@lists.alpinelinux.org"
	<~alpine/users@lists.alpinelinux.org>
Subject: Re: Sporadic, unpredictable docker / docker-compose (on Alpine 3.13)
 issues with DNS name resolution
Thread-Topic: Sporadic, unpredictable docker / docker-compose (on Alpine 3.13)
 issues with DNS name resolution
Thread-Index: AQHXEHHoYuy45CagREyBYIomqYDYQqpzCd2A
Date: Thu, 4 Mar 2021 01:26:21 +0000
Message-ID: <8D5539B9-2FF3-4BDD-A06C-F11716D7A8B2@goodeast.com>
References: 
 <CALODqpruOKWhKhs8gShNac3T3=H7SDzdMOpo45zS00f-FCcQ1w@mail.gmail.com>
In-Reply-To: 
 <CALODqpruOKWhKhs8gShNac3T3=H7SDzdMOpo45zS00f-FCcQ1w@mail.gmail.com>
Accept-Language: en-US
Content-Language: en-US
Content-Type: multipart/signed;
	boundary="Apple-Mail=_CB9B194D-AF9F-45D8-81FC-919A9B9CCD3F";
	protocol="application/pkcs7-signature";
	micalg=sha-256
MIME-Version: 1.0
X-MS-Exchange-CrossTenant-Network-Message-Id: 71eab373-0ceb-4647-a5ca-08d8deac84c5
X-MS-Exchange-CrossTenant-originalarrivaltime: 04 Mar 2021 01:26:21.4183
 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 3bf6c34e-a871-4afa-b6e8-5140c00a5715
X-MS-Exchange-CrossTenant-mailboxtype: HOSTED
X-MS-Exchange-CrossTenant-userprincipalname: 8LIXcWfeWwenPDInD1uYVLfY0GA3lx3f0gUiDHyrXMk7a0li9slB9ienAnMbgrkn+NDNyfRwEsot1ide9GNywA==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: BLAPR06MB6804

--Apple-Mail=_CB9B194D-AF9F-45D8-81FC-919A9B9CCD3F
Content-Transfer-Encoding: quoted-printable
Content-Type: text/plain;
	charset=utf-8

I just ran into this as well. I=E2=80=99m not using it for production so =
I wasn=E2=80=99t worried about it until I saw this email. Restarting the =
docker daemon seemed to fix things. I hadn=E2=80=99t used my Docker =
system for a almost year (working on other projects) and didn=E2=80=99t =
see this problem back then.=20

My docker system is:
Alpine 3.12.4
Docker version 20.10.3, build 48d30b5b32e99c932b4ea3edca74353feddd83ff
docker-compose version 1.25.4, build unknown=20

Running as a qemu guest on Proxmox 6.3-4, 1.11 GB RAM used of 16 GB =
allocated, 4 vCPUs available. 570 MB used out of a 16 GB boot disk. =
Docker images and containers are stored on an iSCSI mount coming from a =
FreeNAS server hosted on the same hardware.=20

Underlying hardware is a SuperMicro X11SDV-4C-TLN2F Server Motherboard - =
Intel Xeon D-2123IT Quad-core (4 Core) 2.20 GHz, 64 GB RAM, LSI 9207-8i =
HBA, 8 x 4 GB Ironwolf drives, 3 x Samsung 860 EVO 250 GB SSD, 1 x =
Samsung EVO 860 500 GB SSD.=20

Is it worth filing a bug? And where should the bug be filed?=20


=E2=80=94Paul


>=20
> On Mar 3, 2021, at 4:11 PM, Banibrata Dutta =
<banibrata.dutta@gmail.com> wrote:
>=20
> Hi Folks,
>=20
> Have been using docker and docker-compose inside Virtualbox VMs =
running Alpine 3.13 guestOS, on a Windows 10 Professional host. The =
Alpine Guest has 2 vCPUs, 4GB vRAM, and even when all containers are =
running the RAM usage remains below 1GB.
>=20
> 	=E2=80=A2 Docker version 20.10.3, build =
48d30b5b32e99c932b4ea3edca74353feddd83ff
> 	=E2=80=A2 docker-compose version 1.27.4, build unknown
> I use 2 docker-compose .yml files to bring up, 2 set of containers. =
First .yml file brings up Telgraf, InfluxDB, Grafana containers based on =
images from DockerHub. The second .yml brings up a POJO-server (Java) =
with application and another 3 tester/simulators.They all share a =
dedicated network =E2=80=98mynet=E2=80=99 (using bridged driver). The =
above setup seems to work perfectly at times. For example:
>=20
> 	=E2=80=A2 Sometimes , containers don=E2=80=99t seem to get =
hostname assigned (i.e. the mnemonic container-id is set as hostname, as =
is default) while at other times specific hostname is indeed assigned.
>=20
> 	=E2=80=A2 Then, for a few containers (not all), the =
inter-container DNS/name resolution doesn=E2=80=99t seem to work, but at =
the same time few other containers have perfectly working =
inter-container DNS/name resolution. When inter-container DNS resolution =
does-not, if I log into the container runtime using =E2=80=98docker exec =
-it bash=E2=80=99, and try to do 'ping ', I get the following error:
> ping: somehostname: Temporary failure in name resolution
>=20
> 	=E2=80=A2 Sometimes, some containers (not all) require the =
"service: > hostname: " declaration in the docker-compose .yml file to =
get specific hostname assigned to the container, but for other =
containers at other times, that declaration is not needed, and only the =
=E2=80=9Ccontainer_name=E2=80=9D declaration is enough (in .yml file) to =
have specific hostname for that container !!
>=20
> Wondering if anyone can help figure out why is the behaviour erratic ? =
What can I do to fix it ? Is this an issue with Docker only on Alpine ?
>=20
> Thanks in anticipation.
>=20
> regards,
> BD


--Apple-Mail=_CB9B194D-AF9F-45D8-81FC-919A9B9CCD3F
Content-Disposition: attachment;
	filename=smime.p7s
Content-Type: application/pkcs7-signature;
	name=smime.p7s
Content-Transfer-Encoding: base64
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--Apple-Mail=_CB9B194D-AF9F-45D8-81FC-919A9B9CCD3F--