DevOps Classroomnotes 27/Nov/2022

Docker Compose contd..

Building image as part of docker-compose

• Refer Here for the docker compose file created for students course register example used in class yesterday
• Now lets add a persistent volume Refer Here
• Refer Here for the changes done in the docker compose file to include volumes
• Execute docker compose up
  
• Now generate some data and execute docker compose down.
• Bring the containers up by executing docker compose up -d and you should be able to see the data generated as docker compose down will not remove volumes, rather it removes containers and networks.

Docker container restrictions, logging etc

• Refer Here for the blog article.
• Run jenkins container

docker container run --name jenkins -d -P jenkins/jenkins:latest

• Inspect container

$ docker container inspect jenkins
[
    {
        "Id": "eabdb70aabc449e74ec84846bc77bd0140d1d84c6b9b3c5dfa760558a9126977",
        "Created": "2022-11-27T03:19:18.918322685Z",
        "Path": "/usr/bin/tini",
        "Args": [
            "--",
            "/usr/local/bin/jenkins.sh"
        ],
        "State": {
            "Status": "running",
            "Running": true,
            "Paused": false,
            "Restarting": false,
            "OOMKilled": false,
            "Dead": false,
            "Pid": 5755,
            "ExitCode": 0,
            "Error": "",
            "StartedAt": "2022-11-27T03:19:19.313928199Z",
            "FinishedAt": "0001-01-01T00:00:00Z"
        },
        "Image": "sha256:fc282a1cac33030915a7b45a1c3ef3fc62f9a74549d9a53c2a5718747d697d6b",
        "ResolvConfPath": "/var/lib/docker/containers/eabdb70aabc449e74ec84846bc77bd0140d1d84c6b9b3c5dfa760558a9126977/resolv.conf",
        "HostnamePath": "/var/lib/docker/containers/eabdb70aabc449e74ec84846bc77bd0140d1d84c6b9b3c5dfa760558a9126977/hostname",
        "HostsPath": "/var/lib/docker/containers/eabdb70aabc449e74ec84846bc77bd0140d1d84c6b9b3c5dfa760558a9126977/hosts",
        "LogPath": "/var/lib/docker/containers/eabdb70aabc449e74ec84846bc77bd0140d1d84c6b9b3c5dfa760558a9126977/eabdb70aabc449e74ec84846bc77bd0140d1d84c6b9b3c5dfa760558a9126977-json.log",
        "Name": "/jenkins",
        "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": {},
            "RestartPolicy": {
                "Name": "no",
                "MaximumRetryCount": 0
            },
            "AutoRemove": false,
            "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": true,
            "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/overlay2/71854daa56c3e6f862914e3e7dd13b5cd1251486b2e65a872a59be4f005cdf53-init/diff:/var/lib/docker/overlay2/e41539548c28c67d862f9e4081e78f6835810a96ef5677f348722d0bb723d20d/diff:/var/lib/docker/overlay2/25766e8a597c7619d7ab3cb8890b512f0690d0bf6dd6ea2b25a1afce71a01eb7/diff:/var/lib/docker/overlay2/7850ee0d0b58af7b58ae44a457fc8048d0f9c43a8350e0f3b315eb1910c45419/diff:/var/lib/docker/overlay2/dbc0215d3c715ff899ed562c56c9b36e0acf0941e1aae0047f9c512064e42b16/diff:/var/lib/docker/overlay2/5996be5561bc4d2232f16333ce930dc061462ddfb4087a938433fc47a381a2f0/diff:/var/lib/docker/overlay2/d3a5b1318932dd29aa7f5115c61a1cc375a8fd0157ebf214df30888aa28a42bb/diff:/var/lib/docker/overlay2/227e5eb46bf9cdb764e4096a142305f0ffb87cd290b6ed9676f3af6fbdb2c4a7/diff:/var/lib/docker/overlay2/40a0514f7f27620f684376c87748a682107ac6360668706de3640b1a7e2366c8/diff:/var/lib/docker/overlay2/2f0e642c3a01d20715cd87bb22d201354ecc14c69aca2510e9b85289b260b8f1/diff:/var/lib/docker/overlay2/e74b7eaf5e63fa6cf912ae866916c03bc92922b493802bd7532d0cdada3cea52/diff:/var/lib/docker/overlay2/79305f2abb966ed3c829c5291ad49a1b70481f30df9d713274c5a93f6e4bcc47/diff:/var/lib/docker/overlay2/d8485cfc6d5852a5cba727e1c77bda8f57f86e54f7194aa3d84ce1d0f0647d9b/diff:/var/lib/docker/overlay2/8860dcdc833b39493ca8b4db03c5da444114fd5b6f4f4f1603738c32d1c1538e/diff",
                "MergedDir": "/var/lib/docker/overlay2/71854daa56c3e6f862914e3e7dd13b5cd1251486b2e65a872a59be4f005cdf53/merged",
                "UpperDir": "/var/lib/docker/overlay2/71854daa56c3e6f862914e3e7dd13b5cd1251486b2e65a872a59be4f005cdf53/diff",
                "WorkDir": "/var/lib/docker/overlay2/71854daa56c3e6f862914e3e7dd13b5cd1251486b2e65a872a59be4f005cdf53/work"
            },
            "Name": "overlay2"
        },
        "Mounts": [
            {
                "Type": "volume",
                "Name": "39ffeae0a0b345dd644018a835ba31849f36259f23a508cf3a2ec0968beb6685",
                "Source": "/var/lib/docker/volumes/39ffeae0a0b345dd644018a835ba31849f36259f23a508cf3a2ec0968beb6685/_data",
                "Destination": "/var/jenkins_home",
                "Driver": "local",
                "Mode": "",
                "RW": true,
                "Propagation": ""
            }
        ],
        "Config": {
            "Hostname": "eabdb70aabc4",
            "Domainname": "",
            "User": "jenkins",
            "AttachStdin": false,
            "AttachStdout": false,
            "AttachStderr": false,
            "ExposedPorts": {
                "50000/tcp": {},
                "8080/tcp": {}
            },
            "Tty": false,
            "OpenStdin": false,
            "StdinOnce": false,
            "Env": [
                "PATH=/opt/java/openjdk/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
                "LANG=C.UTF-8",
                "JENKINS_HOME=/var/jenkins_home",
                "JENKINS_SLAVE_AGENT_PORT=50000",
                "REF=/usr/share/jenkins/ref",
                "JENKINS_VERSION=2.379",
                "JENKINS_UC=https://updates.jenkins.io",
                "JENKINS_UC_EXPERIMENTAL=https://updates.jenkins.io/experimental",
                "JENKINS_INCREMENTALS_REPO_MIRROR=https://repo.jenkins-ci.org/incrementals",
                "COPY_REFERENCE_FILE_LOG=/var/jenkins_home/copy_reference_file.log",
                "JAVA_HOME=/opt/java/openjdk"
            ],
            "Cmd": null,
            "Image": "jenkins/jenkins:latest",
            "Volumes": {
                "/var/jenkins_home": {}
            },
            "WorkingDir": "",
            "Entrypoint": [
                "/usr/bin/tini",
                "--",
                "/usr/local/bin/jenkins.sh"
            ],
            "OnBuild": null,
            "Labels": {
                "org.opencontainers.image.description": "The Jenkins Continuous Integration and Delivery server",
                "org.opencontainers.image.licenses": "MIT",
                "org.opencontainers.image.revision": "979b513098fcb4e37675fe19fe904fb6e07f1b05",
                "org.opencontainers.image.source": "https://github.com/jenkinsci/docker",
                "org.opencontainers.image.title": "Official Jenkins Docker image",
                "org.opencontainers.image.url": "https://www.jenkins.io/",
                "org.opencontainers.image.vendor": "Jenkins project",
                "org.opencontainers.image.version": "2.379"
            }
        },
        "NetworkSettings": {
            "Bridge": "",
            "SandboxID": "d9b561e53663f0e213b7078f1466863a0cc5ce6f3d9169dfbcc3bea551d6e5ec",
            "HairpinMode": false,
            "LinkLocalIPv6Address": "",
            "LinkLocalIPv6PrefixLen": 0,
            "Ports": {
                "50000/tcp": [
                    {
                        "HostIp": "0.0.0.0",
                        "HostPort": "49153"
                    },
                    {
                        "HostIp": "::",
                        "HostPort": "49153"
                    }
                ],
                "8080/tcp": [
                    {
                        "HostIp": "0.0.0.0",
                        "HostPort": "49154"
                    },
                    {
                        "HostIp": "::",
                        "HostPort": "49154"
                    }
                ]
            },
            "SandboxKey": "/var/run/docker/netns/d9b561e53663",
            "SecondaryIPAddresses": null,
            "SecondaryIPv6Addresses": null,
            "EndpointID": "d430c74f044d7dd019f6737e7b87cba75edaac9eadb168490670c07466b1e70e",
            "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": "11ac3cc1ec070c901195ef46bb93005a9c0889e3207766962992835c7de24fdd",
                    "EndpointID": "d430c74f044d7dd019f6737e7b87cba75edaac9eadb168490670c07466b1e70e",
                    "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
                }
            }
        }
    }
]

• top command
  
• to know the stats resources consumed by containers docker container stats
  
• to look at logs generated by container on STDOUT, STDERR docker container logs
• Login into running container docker container run -it <name> <shell>
  
• Containers can be paused and unpaused
  
• To stop the contianer docker container stop and to start it back docker container start
• Lets run the portainer container which shows the information about networks, volumes, images, events about the containers running on a host

docker container run -d -p 8000:8000 -p 9443:9443 --name portainer --restart=always -v /var/run/docker.sock:/var/run/docker.sock -v portainer_data:/data portainer/portainer-ce:latest

• Run a container with restricted memory docker container run --name jenkins2 --memory 1024m -d -P jenkins/jenkins:latest
  
• To run a container with restrictions refer docker container run --help

Docker Registries

• Registry is used to store the docker images.
• Docker images are OCI (Open Container initiative) compliant
• Overview in Pipeline
  
• There are two types of registries
  • public registry: Open to all for usage
    • Example: Docker hub
  • private registry: Registry for internal usage with in organization
    • Examples:
      • Docker hub (private)
      • Azure Container Registry
      • AWS Container Registry
      • JFROG/Artifcatory
      • Refer Here docker registry image
• Lets build a student course registry
• Build the student course rest service with the following command

docker image build -t scr:1.0 .

• Generally registries will have repositories, each repository represents an application. The naming conventions slightly differ from registry to registry.
• Docker hub: Naming convention is <account-name>/<image-name>:<tag>
  • account name => shaikkhajaibrahim
  • image name: scr
  • tag: 1.0
• Now let me tag the already built image scr:1.0 to shaikkhajaibrahim/scr:1.0

docker image tag scr:1.0 shaikkhajaibrahim/scr:1.0

* Now we need to login into docker hub docker login

* Now lets push the image


* Now let me use this image in docker playground