How to use localhost to access Docker containers

[cyberwombat]

Trying to switch to colima from Docker Desktop on mac but having issues reaching my containers on localhost.

Removed Docker Desktop and installed colimna/docker w homebrew. Colima starts fine.

I have a command that I use to run Dynamo:

docker run --name dynamodb -d -p 8000:8000 amazon/dynamodb-local"

When I was using Docker Desktop I could reach the database on localhost:8000. Now it's only accessible on 127.0.0.1:8000

My /etc/hosts correctly maps localhost - this is an issue with the switch. Not finding much online regarding this - any ideas? It seems that docker no longer recognizes localhost as an alias for 127.0.0.1 after the switch. Not using Kubernetes or docker compose.

I am on MacOS Ventura, latest colima (also tried --HEAD from homebrew). From what I read it localhost should work - any idea what to look at?

[abiosoft]

What does localhost point to in your /etc/hosts?

[cyberwombat]

/etc/hosts

127.0.0.1       localhost
255.255.255.255 broadcasthost
::1             localhost

colima status

INFO[0000] colima is running using QEMU                 
INFO[0000] arch: x86_64                                 
INFO[0000] runtime: docker                              
INFO[0000] mountType: sshfs                             
INFO[0000] address: 192.168.106.2                       
INFO[0000] socket: unix:///Users/Me/.colima/default/docker.sock 

[cyberwombat]

I have been using docker run --name dynamodb -d -p 8000:8000 amazon/dynamodb-local" with Docker Dekstop and then for example launching the web admin with DYNAMO_ENDPOINT=http://localhost:8000 AWS_REGION=us-east-1 dynamodb-admin". This will work if I do either 127.0.0.1:8000 or 192.168.106.2:8000 but not localhost. However the web admin works fine on localhost:8001 so localhost mapping is working fine.

Not sure if useful but doing docker inspect dybamodb yields:

[
    {
        "Id": "ebf16c16e43348ca6cf6a3b5077c22db56dabf4203f37bb9f6dfef70c5f099a4",
        "Created": "2023-01-05T14:55:22.384031355Z",
        "Path": "java",
        "Args": [
            "-jar",
            "DynamoDBLocal.jar",
            "-inMemory"
        ],
        "State": {
            "Status": "running",
            "Running": true,
            "Paused": false,
            "Restarting": false,
            "OOMKilled": false,
            "Dead": false,
            "Pid": 3573,
            "ExitCode": 0,
            "Error": "",
            "StartedAt": "2023-01-05T14:55:22.915228787Z",
            "FinishedAt": "0001-01-01T00:00:00Z"
        },
        "Image": "sha256:7d58d8582d10bef99dbbb0d270f830c40596c627c19e528136e218a3935c7c8a",
        "ResolvConfPath": "/var/lib/docker/containers/ebf16c16e43348ca6cf6a3b5077c22db56dabf4203f37bb9f6dfef70c5f099a4/resolv.conf",
        "HostnamePath": "/var/lib/docker/containers/ebf16c16e43348ca6cf6a3b5077c22db56dabf4203f37bb9f6dfef70c5f099a4/hostname",
        "HostsPath": "/var/lib/docker/containers/ebf16c16e43348ca6cf6a3b5077c22db56dabf4203f37bb9f6dfef70c5f099a4/hosts",
        "LogPath": "/var/lib/docker/containers/ebf16c16e43348ca6cf6a3b5077c22db56dabf4203f37bb9f6dfef70c5f099a4/ebf16c16e43348ca6cf6a3b5077c22db56dabf4203f37bb9f6dfef70c5f099a4-json.log",
        "Name": "/dynamodb",
        "RestartCount": 0,
        "Driver": "overlay2",
        "Platform": "linux",
        "MountLabel": "",
        "ProcessLabel": "",
        "AppArmorProfile": "",
        "ExecIDs": null,
        "HostConfig": {
            "Binds": null,
            "ContainerIDFile": "",
            "LogConfig": {
                "Type": "json-file",
                "Config": {}
            },
            "NetworkMode": "default",
            "PortBindings": {
                "8000/tcp": [
                    {
                        "HostIp": "",
                        "HostPort": "8000"
                    }
                ]
            },
            "RestartPolicy": {
                "Name": "no",
                "MaximumRetryCount": 0
            },
            "AutoRemove": true,
            "VolumeDriver": "",
            "VolumesFrom": null,
            "CapAdd": null,
            "CapDrop": null,
            "CgroupnsMode": "host",
            "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/overlay2/8501061687e30d90b23a246779d324c72e1700b32e3d3a045422ba5f7e1a4092-init/diff:/var/lib/docker/overlay2/2ee15db326667e3a20e8ccd2cfe44e80f3804e4fbbdf4da582e8cd28e284e5a9/diff:/var/lib/docker/overlay2/914424e61320fee566f8e4c4ba91b99d1d53f44306f320b701af050513ef7c6f/diff:/var/lib/docker/overlay2/e76537590129a70d86dbbd372c691b4d7272cc03d30859632cd3c112588228e5/diff:/var/lib/docker/overlay2/dbb9a142701ee4def551a944e58a97fbe74790f54e95d73a9bbc93a1dbe031ea/diff",
                "MergedDir": "/var/lib/docker/overlay2/8501061687e30d90b23a246779d324c72e1700b32e3d3a045422ba5f7e1a4092/merged",
                "UpperDir": "/var/lib/docker/overlay2/8501061687e30d90b23a246779d324c72e1700b32e3d3a045422ba5f7e1a4092/diff",
                "WorkDir": "/var/lib/docker/overlay2/8501061687e30d90b23a246779d324c72e1700b32e3d3a045422ba5f7e1a4092/work"
            },
            "Name": "overlay2"
        },
        "Mounts": [],
        "Config": {
            "Hostname": "ebf16c16e433",
            "Domainname": "",
            "User": "dynamodblocal",
            "AttachStdin": false,
            "AttachStdout": false,
            "AttachStderr": false,
            "ExposedPorts": {
                "8000/tcp": {}
            },
            "Tty": false,
            "OpenStdin": false,
            "StdinOnce": false,
            "Env": [
                "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
            ],
            "Cmd": [
                "-jar",
                "DynamoDBLocal.jar",
                "-inMemory"
            ],
            "Image": "amazon/dynamodb-local",
            "Volumes": null,
            "WorkingDir": "/home/dynamodblocal",
            "Entrypoint": [
                "java"
            ],
            "OnBuild": null,
            "Labels": {
                "aws.java.sdk.version": "1.20.0"
            }
        },
        "NetworkSettings": {
            "Bridge": "",
            "SandboxID": "05826660be29d646bf1e1218412d086d1539ee3a46cff581bdfc4f25ea1e3425",
            "HairpinMode": false,
            "LinkLocalIPv6Address": "",
            "LinkLocalIPv6PrefixLen": 0,
            "Ports": {
                "8000/tcp": [
                    {
                        "HostIp": "0.0.0.0",
                        "HostPort": "8000"
                    },
                    {
                        "HostIp": "::",
                        "HostPort": "8000"
                    }
                ]
            },
            "SandboxKey": "/var/run/docker/netns/05826660be29",
            "SecondaryIPAddresses": null,
            "SecondaryIPv6Addresses": null,
            "EndpointID": "43ecb187f7f2d7a106a6ce1d106f4df1ae4c55cbf7d061ab2b5716d890128e5f",
            "Gateway": "172.17.0.1",
            "GlobalIPv6Address": "",
            "GlobalIPv6PrefixLen": 0,
            "IPAddress": "172.17.0.2",
            "IPPrefixLen": 16,
            "IPv6Gateway": "",
            "MacAddress": "02:42:ac:11:00:02",
            "Networks": {
                "bridge": {
                    "IPAMConfig": null,
                    "Links": null,
                    "Aliases": null,
                    "NetworkID": "0eba018a34ea148dea4dac846f342bd5edce3d7520c8117a9a80cad9ba13a23a",
                    "EndpointID": "43ecb187f7f2d7a106a6ce1d106f4df1ae4c55cbf7d061ab2b5716d890128e5f",
                    "Gateway": "172.17.0.1",
                    "IPAddress": "172.17.0.2",
                    "IPPrefixLen": 16,
                    "IPv6Gateway": "",
                    "GlobalIPv6Address": "",
                    "GlobalIPv6PrefixLen": 0,
                    "MacAddress": "02:42:ac:11:00:02",
                    "DriverOpts": null
                }
            }
        }
    }
]

But this the same image/command I have been using for a long time.

[bourquep]

Did you end up figuring this out? I'm experiencing the same problem.

[cyberwombat]

Nah. Tried a few times but gave up and back to Docker

[abiosoft]

The issue here is that I am unable to reproduce it.

I have a command that I use to run Dynamo:

docker run --name dynamodb -d -p 8000:8000 amazon/dynamodb-local"

How do you test your dynamodb connection, what client do you use? I am able to communicate with localhost:8000

This my /etc/hosts.

##
# Host Database
#
# localhost is used to configure the loopback interface
# when the system is booting.  Do not change this entry.
##
127.0.0.1	localhost
255.255.255.255	broadcasthost
::1             localhost

[abiosoft]

Seems this might be related lima-vm/lima#1330

[lukasstanek]

Hi,
got the same problem on my machine is there any news, regarding this issue?

[mfestrada]

Hope this helps someone else...

I stumbled up on this after running docker-compose up and not being able to hit the service on either localhost or 127.0.0.1. I found this line in my default VM config file:

# file: ~/.lima/default/lima.yaml
propagateProxyEnv: null

I updated this value to true and restarted my vm, and now it's happy at localhost. The comments mention true as the default value, but it was null in my case.

[riverfour]

So I edit the file ~/.lima/colima/colima.yaml and restart colima. Still "localhost:8181" got connection reset.

File content:

cpu: 4

disk: 60

memory: 16

arch: x86_64

runtime: docker

propagateProxyEnv: true

(...omitted)

[riverfour]

I rebooted my Mac, and now localhost:8181 can be accessed. It appears the previous tries might not clean on the localhost:8181 port.

[rakesh-vardan]

Thank you, this solution works for me also with colima v0.6.7 & docker-compose. Worked for me with restarting the colima, without a mac reboot though!

[ismaelga]

I can't find that config on mac :(
Tried running colima start --edit but there's no propagateProxyEnv there.
~/.lima does not exist on my machine

[izzyandrade]

@ismaelga my config file also didn't have any propagateProxyEnv, but I added it anyway, and it worked, can access localhost now

[brianclinkenbeard]

In case it's helpful to others having their connection reset on localhost, make sure your app itself is binding to 0.0.0.0 rather than localhost or 127.0.0.1, which won't work using Docker in general.