Can't connect to PostgreSQL docker image (with a forwarded port)

Question

I created my docker image with the following command -

sudo docker run -d --name pg1 -e POSTGRES_PASSWORD=pass -p 5431:5432 postgres

I tried connecting using psql -

psql -h 127.0.0.1 -p 5431

and after a while it returns -

psql: error: could not connect to server: server closed the connection unexpectedly
    This probably means the server terminated abnormally
    before or while processing the request.

The output to docker ps -

CONTAINER ID        IMAGE                   COMMAND                  CREATED             STATUS              PORTS                                                                                        NAMES
7544edb21da1        postgres                "docker-entrypoint.s…"   4 minutes ago       Up 4 minutes        0.0.0.0:5431->5432/tcp            

                                                       pg1

The output to docker inspect -

[
    {
        "Id": "7544edb21da1f0eba57fe6e010ca95f763dc8224f347c096aa2c8409d21a9368",
        "Created": "2020-10-18T12:27:00.829493238Z",
        "Path": "docker-entrypoint.sh",
        "Args": [
            "postgres"
        ],
        "State": {
            "Status": "running",
            "Running": true,
            "Paused": false,
            "Restarting": false,
            "OOMKilled": false,
            "Dead": false,
            "Pid": 248693,
            "ExitCode": 0,
            "Error": "",
            "StartedAt": "2020-10-18T12:27:01.372006934Z",
            "FinishedAt": "0001-01-01T00:00:00Z"
        },
        "Image": "sha256:c96f8b6bc0d9f0277f118cf485a8c302e32cfe05e7d65f6e9a4c106679439d5e",
        "ResolvConfPath": "/var/lib/docker/containers/7544edb21da1f0eba57fe6e010ca95f763dc8224f347c096aa2c8409d21a9368/resolv.conf",
        "HostnamePath": "/var/lib/docker/containers/7544edb21da1f0eba57fe6e010ca95f763dc8224f347c096aa2c8409d21a9368/hostname",
        "HostsPath": "/var/lib/docker/containers/7544edb21da1f0eba57fe6e010ca95f763dc8224f347c096aa2c8409d21a9368/hosts",
        "LogPath": "/var/lib/docker/containers/7544edb21da1f0eba57fe6e010ca95f763dc8224f347c096aa2c8409d21a9368/7544edb21da1f0eba57fe6e010ca95f763dc8224f347c096aa2c8409d21a9368-json.log",
        "Name": "/pg1",
        "RestartCount": 0,
        "Driver": "overlay2",
        "Platform": "linux",
        "MountLabel": "",
        "ProcessLabel": "",
        "AppArmorProfile": "docker-default",
        "ExecIDs": null,
        "HostConfig": {
            "Binds": null,
            "ContainerIDFile": "",
            "LogConfig": {
                "Type": "json-file",
                "Config": {}
            },
            "NetworkMode": "default",
            "PortBindings": {
                "5432/tcp": [
                    {
                        "HostIp": "",
                        "HostPort": "5431"
                    }
                ]
            },
            "RestartPolicy": {
                "Name": "no",
                "MaximumRetryCount": 0
            },
            "AutoRemove": false,
            "VolumeDriver": "",
            "VolumesFrom": null,
            "CapAdd": null,
            "CapDrop": null,
            "Capabilities": null,
            "Dns": [],
            "DnsOptions": [],
            "DnsSearch": [],
            "ExtraHosts": null,
            "GroupAdd": null,
            "IpcMode": "private",
            "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": [],
            "BlkioDeviceReadBps": null,
            "BlkioDeviceWriteBps": null,
            "BlkioDeviceReadIOps": null,
            "BlkioDeviceWriteIOps": null,
            "CpuPeriod": 0,
            "CpuQuota": 0,
            "CpuRealtimePeriod": 0,
            "CpuRealtimeRuntime": 0,
            "CpusetCpus": "",
            "CpusetMems": "",
            "Devices": [],
            "DeviceCgroupRules": null,
            "DeviceRequests": null,
            "KernelMemory": 0,
            "KernelMemoryTCP": 0,
            "MemoryReservation": 0,
            "MemorySwap": 0,
            "MemorySwappiness": null,
            "OomKillDisable": false,
            "PidsLimit": null,
            "Ulimits": null,
            "CpuCount": 0,
            "CpuPercent": 0,
            "IOMaximumIOps": 0,
            "IOMaximumBandwidth": 0,
            "MaskedPaths": [
                "/proc/asound",
                "/proc/acpi",
                "/proc/kcore",
                "/proc/keys",
                "/proc/latency_stats",
                "/proc/timer_list",
                "/proc/timer_stats",
                "/proc/sched_debug",
                "/proc/scsi",
                "/sys/firmware"
            ],
            "ReadonlyPaths": [
                "/proc/bus",
                "/proc/fs",
                "/proc/irq",
                "/proc/sys",
                "/proc/sysrq-trigger"
            ]
        },
        "GraphDriver": {
            "Data": {
                "LowerDir": "/var/lib/docker/overlay2/40586201c29ccea2586cba608e6fb64dffd5ece30d89cc1087ee2e43a7a5b746-init/diff:/var/lib/docker/overlay2/5cb4a9544fb587c2fb21b8934c88a5c20d468d417efbb9b548c12c3da0dea207/diff:/var/lib/docker/overlay2/7bf8dd38278f17616c2b8ad798787db97f2f899175a613deb3f0cdff243793e3/diff:/var/lib/docker/overlay2/cd3006fdad38af40b2bceb3b1e71e70cdf341faad0f1fc035d9e9fbef6dd57b8/diff:/var/lib/docker/overlay2/29c9aceb670eb25359c1c0b2880e781137ef8e64bc3b54f2a3b7838f1e082f3d/diff:/var/lib/docker/overlay2/02cc88690586248e33d42a8b69af97d65b53e9777daf31f7fde20146fe632aad/diff:/var/lib/docker/overlay2/ac82aefa647c8172c2f0a32024bcfdb26216503779a0874ce28de6844ac5fcfb/diff:/var/lib/docker/overlay2/ead4901bcad157e446a77e1ffe8e11bd16e3bf07c5107f297144066f95f40bfb/diff:/var/lib/docker/overlay2/ebc2bb6cb6811988a05818275f133045e61ed50660045b4a912d5fdc1b6fc651/diff:/var/lib/docker/overlay2/545fef5599babc61f384e20617a705d76cfbffd0abc93a1f0dd9a0d0f4ce3ab2/diff:/var/lib/docker/overlay2/a096d23ddb6f5971d55f3dd5a74cecb6461bed20b03d0f568cc21009d1f5d7e7/diff:/var/lib/docker/overlay2/8add50b416d00917dbee83a176f67dee2e974cc0e5741810181cd74170e0928d/diff:/var/lib/docker/overlay2/594f6265418c37118caa08de40a1d4f1cbbf60fc3c557575c67b545b9454a3fc/diff:/var/lib/docker/overlay2/a4e8ba0efb607e5d8af671039b5ecb9536b6dc48d3c525ce034de22ecd76c331/diff:/var/lib/docker/overlay2/07b1f48b8e0462fb5359411156635b73321b9555bf23cff2036dfe0d69ea1ea5/diff",
                "MergedDir": "/var/lib/docker/overlay2/40586201c29ccea2586cba608e6fb64dffd5ece30d89cc1087ee2e43a7a5b746/merged",
                "UpperDir": "/var/lib/docker/overlay2/40586201c29ccea2586cba608e6fb64dffd5ece30d89cc1087ee2e43a7a5b746/diff",
                "WorkDir": "/var/lib/docker/overlay2/40586201c29ccea2586cba608e6fb64dffd5ece30d89cc1087ee2e43a7a5b746/work"
            },
            "Name": "overlay2"
        },
        "Mounts": [
            {
                "Type": "volume",
                "Name": "8f60dae263f54c3c9e38a37b1c86512dffa254f77830de8d5a5e260c94e69319",
                "Source": "/var/lib/docker/volumes/8f60dae263f54c3c9e38a37b1c86512dffa254f77830de8d5a5e260c94e69319/_data",
                "Destination": "/var/lib/postgresql/data",
                "Driver": "local",
                "Mode": "",
                "RW": true,
                "Propagation": ""
            }
        ],
        "Config": {
            "Hostname": "7544edb21da1",
            "Domainname": "",
            "User": "",
            "AttachStdin": false,
            "AttachStdout": false,
            "AttachStderr": false,
            "ExposedPorts": {
                "5432/tcp": {}
            },
            "Tty": false,
            "OpenStdin": false,
            "StdinOnce": false,
            "Env": [
                "POSTGRES_PASSWORD=pass",
                "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/lib/postgresql/13/bin",
                "GOSU_VERSION=1.12",
                "LANG=en_US.utf8",
                "PG_MAJOR=13",
                "PG_VERSION=13.0-1.pgdg100+1",
                "PGDATA=/var/lib/postgresql/data"
            ],
            "Cmd": [
                "postgres"
            ],
            "Image": "postgres",
            "Volumes": {
                "/var/lib/postgresql/data": {}
            },
            "WorkingDir": "",
            "Entrypoint": [
                "docker-entrypoint.sh"
            ],
            "OnBuild": null,
            "Labels": {},
            "StopSignal": "SIGINT"
        },
        "NetworkSettings": {
            "Bridge": "",
            "SandboxID": "15915142f795248c698fd8dacafc8eadd6dd940a46ff21a00c31a8b5cb6bbb10",
            "HairpinMode": false,
            "LinkLocalIPv6Address": "",
            "LinkLocalIPv6PrefixLen": 0,
            "Ports": {
                "5432/tcp": [
                    {
                        "HostIp": "0.0.0.0",
                        "HostPort": "5431"
                    }
                ]
            },
            "SandboxKey": "/var/run/docker/netns/15915142f795",
            "SecondaryIPAddresses": null,
            "SecondaryIPv6Addresses": null,
            "EndpointID": "e76fa7145141ec7ff5a088135f096ab8bbdbdf6fe06fd69e229fc152a4dee779",
            "Gateway": "172.17.0.1",
            "GlobalIPv6Address": "",
            "GlobalIPv6PrefixLen": 0,
            "IPAddress": "172.17.0.4",
            "IPPrefixLen": 16,
            "IPv6Gateway": "",
            "MacAddress": "02:42:ac:11:00:04",
            "Networks": {
                "bridge": {
                    "IPAMConfig": null,
                    "Links": null,
                    "Aliases": null,
                    "NetworkID": "5e91a000cbb899564472694a4bbddb4b3e4009c6944d0c801d1473ef71d61fe6",
                    "EndpointID": "e76fa7145141ec7ff5a088135f096ab8bbdbdf6fe06fd69e229fc152a4dee779",
                    "Gateway": "172.17.0.1",
                    "IPAddress": "172.17.0.4",
                    "IPPrefixLen": 16,
                    "IPv6Gateway": "",
                    "GlobalIPv6Address": "",
                    "GlobalIPv6PrefixLen": 0,
                    "MacAddress": "02:42:ac:11:00:04",
                    "DriverOpts": null
                }
            }
        }
    }
]

Connecting to the SQL server inside the container works. But outside it doesn't work.
What can be done here? What am I missing?

Answer 1

First of all, you didn't create a docker image, you created a docker container named: pg1 from the official image postgres,

Based on your docker inspect the output, I think it will work on host 172.17.0.4 and port 5432. So try below command -

psql -h 172.17.0.4 -p 5432

With pgadmin(if you set it up),

 host: 172.17.0.4
 port: 5432
 username: postgres
 password: pass

Also, this will help you why the current psql -h 127.0.0.1 -p 5431 way is not working, "psql: could not connect to server: Connection refused" Error when connecting to remote database

Answer 2

For me the issue was caused by having my VPN client running. Worked again when disconnecting it.

Answer 3

Had the same issue. Restarting docker helped, in my case it was:

sudo service docker restart 

Spent some time on this, may this save someone else's time )