Docker expose service to achieve dockerized wordpress multisite

Question

I have been trying to enable Wordpress multisite network for a dockerized Wordpress application. The application can be accessed via IP and port like this:

http://0.0.0.0:8282

When I enable WP_ALLOW_MULTISITE in wp-config.php I get the error from Wordpress that I can not use domain names with port e.g. :8282 in this particular case.

So I was looking for a way how to expose some domain name from Docker container, instead of 0.0.0.0:8282

I found this example:

https://www.theimpossiblecode.com/blog/docker-wordpress-multisite-with-subdomains/

And I went over the example to make it work, as it is described. Then I intend to look for a way how to implement it for my particular application.

The problem:

I started by exposing a service, described on linked page:

https://www.theimpossiblecode.com/blog/docker-expose-service/

I used the enclosed docker-compose.yml from that page, and when I run

$ docker-compose up -d

the containers appear to be working:

CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                 NAMES
edaeb215b3eb        wordpress:latest    "docker-entrypoint.s…"   34 minutes ago      Up 34 minutes       80/tcp                dockwpress_wordpress_1
5dc6fa8480c6        mysql:5.7           "docker-entrypoint.s…"   34 minutes ago      Up 34 minutes       3306/tcp, 33060/tcp   dockwpress_db_1

But, I can't access: http://dockerwp and $ dig dockerwp yields this:

; <<>> DiG 9.10.6 <<>> dockerwp
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 23290
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4000
;; QUESTION SECTION:
;dockerwp.          IN  A

;; Query time: 34 msec
;; SERVER: 10.11.137.100#53(10.11.137.100)
;; WHEN: Thu Dec 13 17:05:34 GMT 2018
;; MSG SIZE  rcvd: 37

When inspecting the container I see that the dockerwp domain name has been exposed (the "com.theimpossiblecode.expose.host": "dockerwp" line).

$ docker inspect edaeb215b3eb


[
    {
        "Id": "edaeb215b3eb37e681fed81099c2de65425a4a6c735529366112ba5436e937cb",
        "Created": "2018-12-13T16:28:55.122420503Z",
        "Path": "docker-entrypoint.sh",
        "Args": [
            "apache2-foreground"
        ],
        "State": {
            "Status": "running",
            "Running": true,
            "Paused": false,
            "Restarting": false,
            "OOMKilled": false,
            "Dead": false,
            "Pid": 10823,
            "ExitCode": 0,
            "Error": "",
            "StartedAt": "2018-12-13T16:28:55.733061919Z",
            "FinishedAt": "0001-01-01T00:00:00Z"
        },
        "Image": "sha256:55b751a7663f6d4fdd0d5f3785b0a846868147dceff99dd169f0a33214be3452",
        "ResolvConfPath": "/var/lib/docker/containers/edaeb215b3eb37e681fed81099c2de65425a4a6c735529366112ba5436e937cb/resolv.conf",
        "HostnamePath": "/var/lib/docker/containers/edaeb215b3eb37e681fed81099c2de65425a4a6c735529366112ba5436e937cb/hostname",
        "HostsPath": "/var/lib/docker/containers/edaeb215b3eb37e681fed81099c2de65425a4a6c735529366112ba5436e937cb/hosts",
        "LogPath": "/var/lib/docker/containers/edaeb215b3eb37e681fed81099c2de65425a4a6c735529366112ba5436e937cb/edaeb215b3eb37e681fed81099c2de65425a4a6c735529366112ba5436e937cb-json.log",
        "Name": "/dockwpress_wordpress_1",
        "RestartCount": 0,
        "Driver": "overlay2",
        "Platform": "linux",
        "MountLabel": "",
        "ProcessLabel": "",
        "AppArmorProfile": "",
        "ExecIDs": null,
        "HostConfig": {
            "Binds": [],
            "ContainerIDFile": "",
            "LogConfig": {
                "Type": "json-file",
                "Config": {}
            },
            "NetworkMode": "dockwpress_default",
            "PortBindings": {},
            "RestartPolicy": {
                "Name": "always",
                "MaximumRetryCount": 0
            },
            "AutoRemove": false,
            "VolumeDriver": "",
            "VolumesFrom": [],
            "CapAdd": null,
            "CapDrop": null,
            "Dns": null,
            "DnsOptions": null,
            "DnsSearch": null,
            "ExtraHosts": null,
            "GroupAdd": null,
            "IpcMode": "shareable",
            "Cgroup": "",
            "Links": null,
            "OomScoreAdj": 0,
            "PidMode": "",
            "Privileged": false,
            "PublishAllPorts": false,
            "ReadonlyRootfs": false,
            "SecurityOpt": null,
            "UTSMode": "",
            "UsernsMode": "",
            "ShmSize": 67108864,
            "Runtime": "runc",
            "ConsoleSize": [
                0,
                0
            ],
            "Isolation": "",
            "CpuShares": 0,
            "Memory": 0,
            "NanoCpus": 0,
            "CgroupParent": "",
            "BlkioWeight": 0,
            "BlkioWeightDevice": null,
            "BlkioDeviceReadBps": null,
            "BlkioDeviceWriteBps": null,
            "BlkioDeviceReadIOps": null,
            "BlkioDeviceWriteIOps": null,
            "CpuPeriod": 0,
            "CpuQuota": 0,
            "CpuRealtimePeriod": 0,
            "CpuRealtimeRuntime": 0,
            "CpusetCpus": "",
            "CpusetMems": "",
            "Devices": null,
            "DeviceCgroupRules": null,
            "DiskQuota": 0,
            "KernelMemory": 0,
            "MemoryReservation": 0,
            "MemorySwap": 0,
            "MemorySwappiness": null,
            "OomKillDisable": false,
            "PidsLimit": 0,
            "Ulimits": null,
            "CpuCount": 0,
            "CpuPercent": 0,
            "IOMaximumIOps": 0,
            "IOMaximumBandwidth": 0,
            "MaskedPaths": [
                "/proc/acpi",
                "/proc/kcore",
                "/proc/keys",
                "/proc/latency_stats",
                "/proc/timer_list",
                "/proc/timer_stats",
                "/proc/sched_debug",
                "/proc/scsi",
                "/sys/firmware"
            ],
            "ReadonlyPaths": [
                "/proc/asound",
                "/proc/bus",
                "/proc/fs",
                "/proc/irq",
                "/proc/sys",
                "/proc/sysrq-trigger"
            ]
        },
        "GraphDriver": {
            "Data": {
                "LowerDir": "/var/lib/docker/overlay2/8ab6c3eb7bb9e80de85a5c39849775d339d9466c182b236eca411f1cb32d7f29-init/diff:/var/lib/docker/overlay2/44b78d4977abf7cab796267c277db0e31efd5190f917dce4167237070fb0317e/diff:/var/lib/docker/overlay2/1d3fb40ede0d5e2626d4d1ea19e93cb15702a7bcb569bf2811e652d25409623f/diff:/var/lib/docker/overlay2/f59d3c961f65e7ad1297bf888ed04905dff998a31a5796c7c903a8f854749a3b/diff:/var/lib/docker/overlay2/af222f8ba1e9c68b16935d08a0325ec8ff173a2944082e8d3e568a2c738d591f/diff:/var/lib/docker/overlay2/1bac18c6dc58c3ebd7982dd3ccdfb7fdbc4037de6277c20d84baba95babaf4c1/diff:/var/lib/docker/overlay2/32df749d5027d957ebba6167f8715bbbc117c0787c8d5849f318391d427dfcaf/diff:/var/lib/docker/overlay2/e6927c13204369a44dc8f4de4a8ab8a3307b0f8fa5eb758a565a67a1b923451a/diff:/var/lib/docker/overlay2/a6299eec8f02b0c2a190a9646b7576209e0e39f6bae1d81f543daaabe0dd89d4/diff:/var/lib/docker/overlay2/d0e4d7ff78e7373c4f3885e8cad840617764e9a803bda6eb30e681cdc910bf51/diff:/var/lib/docker/overlay2/fc48c85e773fd6d0e52b4a84116224d2ee0a396a470df44b009fb56ef8276704/diff:/var/lib/docker/overlay2/77aea6e322140a30aff363c97e67bad3f2ab78f301ebdadc89275f9e1e86ad0d/diff:/var/lib/docker/overlay2/fec4aae10fb644332df8a1c286c9635a1ae85f2d9aaf8838ae08b7e6f3268a8d/diff:/var/lib/docker/overlay2/41bfdb4f1afa0d88890af4deb33c403e5816a6b2823d3a9ed5fb19079b4faa9b/diff:/var/lib/docker/overlay2/5aa746815fbdaeedc7a727ca34072f1183af9bc0ba7908b480e37ee9f5884761/diff:/var/lib/docker/overlay2/aa6c25c7e61f3512a55f69ed5c39f492b80a500704bdc9a91af8ff811f74f58d/diff:/var/lib/docker/overlay2/41c27f1bb64072e7deebc7eee4b46f3c38b63e2bc56ebfaf9c88159f1d6c67c2/diff:/var/lib/docker/overlay2/512ece5edecc822e72e5d939d75339e02582696dbc5205f756516c4b635ff9d3/diff:/var/lib/docker/overlay2/7bd7bb38c22c9ee4dd2c38d2c32ac12bbb2034c759879a26b73b351ac7a5e26e/diff:/var/lib/docker/overlay2/602c7d2fa85ca8e4945236214ffb852abcfd716f5626d273b510b470d7878d02/diff",
                "MergedDir": "/var/lib/docker/overlay2/8ab6c3eb7bb9e80de85a5c39849775d339d9466c182b236eca411f1cb32d7f29/merged",
                "UpperDir": "/var/lib/docker/overlay2/8ab6c3eb7bb9e80de85a5c39849775d339d9466c182b236eca411f1cb32d7f29/diff",
                "WorkDir": "/var/lib/docker/overlay2/8ab6c3eb7bb9e80de85a5c39849775d339d9466c182b236eca411f1cb32d7f29/work"
            },
            "Name": "overlay2"
        },
        "Mounts": [
            {
                "Type": "volume",
                "Name": "bd2706aae2dbddaa65a85e77ca89efc3844dc600f72e1e8b1f9b6803cbb8459c",
                "Source": "/var/lib/docker/volumes/bd2706aae2dbddaa65a85e77ca89efc3844dc600f72e1e8b1f9b6803cbb8459c/_data",
                "Destination": "/var/www/html",
                "Driver": "local",
                "Mode": "",
                "RW": true,
                "Propagation": ""
            }
        ],
        "Config": {
            "Hostname": "edaeb215b3eb",
            "Domainname": "",
            "User": "",
            "AttachStdin": false,
            "AttachStdout": false,
            "AttachStderr": false,
            "ExposedPorts": {
                "80/tcp": {}
            },
            "Tty": false,
            "OpenStdin": false,
            "StdinOnce": false,
            "Env": [
                "WORDPRESS_DB_HOST=db:3306",
                "WORDPRESS_DB_USER=wordpress",
                "WORDPRESS_DB_PASSWORD=wordpress",
                "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
                "PHPIZE_DEPS=autoconf \t\tdpkg-dev \t\tfile \t\tg++ \t\tgcc \t\tlibc-dev \t\tmake \t\tpkg-config \t\tre2c",
                "PHP_INI_DIR=/usr/local/etc/php",
                "APACHE_CONFDIR=/etc/apache2",
                "APACHE_ENVVARS=/etc/apache2/envvars",
                "PHP_EXTRA_BUILD_DEPS=apache2-dev",
                "PHP_EXTRA_CONFIGURE_ARGS=--with-apxs2 --disable-cgi",
                "PHP_CFLAGS=-fstack-protector-strong -fpic -fpie -O2",
                "PHP_CPPFLAGS=-fstack-protector-strong -fpic -fpie -O2",
                "PHP_LDFLAGS=-Wl,-O1 -Wl,--hash-style=both -pie",
                "GPG_KEYS=1729F83938DA44E27BA0F4D3DBDB397470D12172 B1B44D8F021E4E2D6021E995DC9FF8D3EE5AF27F",
                "PHP_VERSION=7.2.13",
                "PHP_URL=https://secure.php.net/get/php-7.2.13.tar.xz/from/this/mirror",
                "PHP_ASC_URL=https://secure.php.net/get/php-7.2.13.tar.xz.asc/from/this/mirror",
                "PHP_SHA256=14b0429abdb46b65c843e5882c9a8c46b31dfbf279c747293b8ab950c2644a4b",
                "PHP_MD5=",
                "WORDPRESS_VERSION=5.0",
                "WORDPRESS_SHA1=67758958f14c1dcefe37ce6558d470a4e142893b"
            ],
            "Cmd": [
                "apache2-foreground"
            ],
            "ArgsEscaped": true,
            "Image": "wordpress:latest",
            "Volumes": {
                "/var/www/html": {}
            },
            "WorkingDir": "/var/www/html",
            "Entrypoint": [
                "docker-entrypoint.sh"
            ],
            "OnBuild": null,
            "Labels": {
                "com.docker.compose.config-hash": "c8ce0ffef4cef318c23c0e6142dcb5b42a97df29507969c72a99e95b3343f0ec",
                "com.docker.compose.container-number": "1",
                "com.docker.compose.oneoff": "False",
                "com.docker.compose.project": "dockwpress",
                "com.docker.compose.service": "wordpress",
                "com.docker.compose.version": "1.23.2",
                "com.theimpossiblecode.expose.host": "dockerwp"
            }
        },
        "NetworkSettings": {
            "Bridge": "",
            "SandboxID": "83bdba7bf688685fa842ab8c1c38a53f26af088c2fd1063492ae55cb73cc6cd6",
            "HairpinMode": false,
            "LinkLocalIPv6Address": "",
            "LinkLocalIPv6PrefixLen": 0,
            "Ports": {
                "80/tcp": null
            },
            "SandboxKey": "/var/run/docker/netns/83bdba7bf688",
            "SecondaryIPAddresses": null,
            "SecondaryIPv6Addresses": null,
            "EndpointID": "",
            "Gateway": "",
            "GlobalIPv6Address": "",
            "GlobalIPv6PrefixLen": 0,
            "IPAddress": "",
            "IPPrefixLen": 0,
            "IPv6Gateway": "",
            "MacAddress": "",
            "Networks": {
                "dockwpress_default": {
                    "IPAMConfig": null,
                    "Links": null,
                    "Aliases": [
                        "wordpress",
                        "edaeb215b3eb"
                    ],
                    "NetworkID": "6b7d8cc32a6e208f379a8ecfdf88910c85c575e284ad2e3632520fe86ec937ad",
                    "EndpointID": "a7d991d525463bb83b2eedb78baf59358d8a543f3b5244034eaea6cce99ef525",
                    "Gateway": "172.28.0.1",
                    "IPAddress": "172.28.0.3",
                    "IPPrefixLen": 16,
                    "IPv6Gateway": "",
                    "GlobalIPv6Address": "",
                    "GlobalIPv6PrefixLen": 0,
                    "MacAddress": "02:42:ac:1c:00:03",
                    "DriverOpts": null
                }
            }
        }
    }

]

What could be causing the http://dockerwp to be not accessible?

Browser shows this error:

This site can’t be reached dockerwp’s server IP address could not be found.
Did you mean http://docker.com/?
Search Google for docker wp
ERR_NAME_NOT_RESOLVED

Thank you.

Answer 1

The solution is to use Nginx proxy server e.g. https://github.com/jwilder/nginx-proxy

So by using two containers, one is the proxy and another is Wordpress application docker container, you can add vhost entries to /etc/hosts as 127.0.0.1 devwebsite.local for any of required virtual hosts. Those have to be configured for the WP container, the VIRTUAL_HOST env. variable.

Here is the example:https://github.com/djuro/dockerMultisiteWordpress, the Dockerfile and docker-compose.yml in particular.

I used 2 more containers, for database and GUI db tool (Adminer), but those are both optional.

Answer 2

dockerwp in http://dockerwp is a domain name that does not exist.

You example is only valid if you deploy your wp site to their platform which will give you a subdomain called "dockerwp". The label om.theimpossiblecode.expose.host is read by their reverse proxy to create this effect.

In conclusion you can't set hostname with this configuration. You will be better off just access your site with localhost:port.