Docker - Revision history

Iwiseman: /* Helpful Commands */

2021-08-16T20:53:12Z

Helpful Commands

@@ Line 169: / Line 169: @@
 Some useful bits
 <syntaxhighlight lang="bash">
-# You only need the best match for container in commands
+# General Commands for Docker
 docker container ls
 >49978c1c8547   redis     "docker-entrypoint.s…"   19 seconds ago   Up 18 seconds   6379/tcp, 0.0.0.0:8088->8088/tcp, :::8088->8088/tcp   test
@@ Line 177: / Line 184: @@
 >8088/tcp -> 0.0.0.0:8088
 >8088/tcp -> :::8088
 # Get IP of container
@@ Line 185: / Line 217: @@
 # Clean up containers
 docker container rm $(docker container ls -aq) -f
 </syntaxhighlight>

Iwiseman: /* Docker */

2021-08-16T08:03:19Z

Docker

← Older revision		Revision as of 08:03, 16 August 2021
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	<br>		<br>

	~~=Docker=~~
	~~==Introduction==~~
	Docker Inc. Docker is a company which gave the word technology for containers. They are now a company which provides services around the company.		Docker Inc. Docker is a company which gave the word technology for containers. They are now a company which provides services around the company.
	<br>		<br>
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	The differences between EE and CE are shown below		The differences between EE and CE are shown below
	[[File:Docker Diffs.png\|500px]]		[[File:Docker Diffs.png\|500px]]

	=Architecture=		=Architecture=
	Docker is made up of a docker engine and containers which are comprised of namespaces and control groups. Wiki defines namespaces as '''Namespaces are a feature of the Linux kernel that partitions kernel resources such that one set of processes sees one set of resources while another set of processes sees a different set of resources.'''		Docker is made up of a docker engine and containers which are comprised of namespaces and control groups. Wiki defines namespaces as '''Namespaces are a feature of the Linux kernel that partitions kernel resources such that one set of processes sees one set of resources while another set of processes sees a different set of resources.'''

Iwiseman: /* Introduction */

2021-08-16T08:02:55Z

Introduction

← Older revision		Revision as of 08:02, 16 August 2021
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	=Introduction=		=Introduction=
			This all started with VMWare where the total resource could be divided up to run more than one application on difference virtual machines. But VMWare required an OS on every machine and licenses in the case of Windows. They also needed managing, e.g. patching, Anti-virus and patching. Along came containers which shared the OS.
			<br>
			[[File:Containers Overview.png\|500px]]
			<br>

	=Docker=		=Docker=
	==Introduction==		==Introduction==

Iwiseman: /* Containers */

2021-08-16T08:02:42Z

Containers

← Older revision		Revision as of 08:02, 16 August 2021
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	=Introduction=		=Introduction=
	~~=Containers=~~
	This all started with VMWare where the total resource could be divided up to run more than one application on difference virtual machines. But VMWare required an OS on every machine and licenses in the case of Windows. They also needed managing, e.g. patching, Anti-virus and patching. Along came containers which shared the OS.
	~~<br>~~
	~~[[File:Containers Overview.png\|500px]]~~
	~~<br>~~

	=Docker=		=Docker=
	==Introduction==		==Introduction==

Iwiseman: /* Control Groups */

2021-08-16T07:52:52Z

Control Groups

← Older revision		Revision as of 07:52, 16 August 2021
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	*An interprocess communication (IPC) namespace has its own IPC resources, for example POSIX message queues.		*An interprocess communication (IPC) namespace has its own IPC resources, for example POSIX message queues.
	*A UNIX Time‑Sharing (UTS) namespace allows a single system to appear to have different host and domain names to different processes.		*A UNIX Time‑Sharing (UTS) namespace allows a single system to appear to have different host and domain names to different processes.
	===Control Groups===		==Control Groups==
	A control group (cgroup) is a Linux kernel feature that limits, accounts for, and isolates the resource usage (CPU, memory, disk I/O, network, and so on) of a collection of processes.		A control group (cgroup) is a Linux kernel feature that limits, accounts for, and isolates the resource usage (CPU, memory, disk I/O, network, and so on) of a collection of processes.
	<br>		<br>
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	*Accounting – Resource limits are monitored and reported at the cgroup level.		*Accounting – Resource limits are monitored and reported at the cgroup level.
	*Control – You can change the status (frozen, stopped, or restarted) of all processes in a cgroup with a single command.		*Control – You can change the status (frozen, stopped, or restarted) of all processes in a cgroup with a single command.

	==Docker on Windwos==		==Docker on Windwos==
	Finally a quick image to demonstrate the difference between native and hyper-v containers on windows. They made me do it gov.		Finally a quick image to demonstrate the difference between native and hyper-v containers on windows. They made me do it gov.

Iwiseman: /* Architecture */

2021-08-16T07:52:36Z

Architecture

← Older revision		Revision as of 07:52, 16 August 2021
Line 19:		Line 19:
	The differences between EE and CE are shown below		The differences between EE and CE are shown below
	[[File:Docker Diffs.png\|500px]]		[[File:Docker Diffs.png\|500px]]
	==Architecture==		=Architecture=
	Docker is made up of a docker engine and containers which are comprised of namespaces and control groups. Wiki defines namespaces as '''Namespaces are a feature of the Linux kernel that partitions kernel resources such that one set of processes sees one set of resources while another set of processes sees a different set of resources.'''		Docker is made up of a docker engine and containers which are comprised of namespaces and control groups. Wiki defines namespaces as '''Namespaces are a feature of the Linux kernel that partitions kernel resources such that one set of processes sees one set of resources while another set of processes sees a different set of resources.'''
	<br>		<br>
	===Docker Engine===		==Docker Engine==
	Here are the core elements of the docker engine.		Here are the core elements of the docker engine.
	<br>		<br>
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	When we create a container, this is the workflow. It is the runc which actually the part which creates the container. The components containerd and runc standardized and it is easily possible to swap runc out for any oci compliant runtime.		When we create a container, this is the workflow. It is the runc which actually the part which creates the container. The components containerd and runc standardized and it is easily possible to swap runc out for any oci compliant runtime.
	[[File:DockerEngine Workflow.png\|400px]]		[[File:DockerEngine Workflow.png\|400px]]
	===Namespace Types===		==Namespace Types==
	Within the Linux kernel, there are different types of namespaces. Each namespace has its own unique properties:		Within the Linux kernel, there are different types of namespaces. Each namespace has its own unique properties:
	[[File:Docker namespace arch.png\|400px]]		[[File:Docker namespace arch.png\|400px]]
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	*Accounting – Resource limits are monitored and reported at the cgroup level.		*Accounting – Resource limits are monitored and reported at the cgroup level.
	*Control – You can change the status (frozen, stopped, or restarted) of all processes in a cgroup with a single command.		*Control – You can change the status (frozen, stopped, or restarted) of all processes in a cgroup with a single command.
	===Docker on Windwos===		==Docker on Windwos==
	Finally a quick image to demonstrate the difference between native and hyper-v containers on windows. They made me do it gov.		Finally a quick image to demonstrate the difference between native and hyper-v containers on windows. They made me do it gov.
	<br>		<br>
	[[File:Docker on Windows.png\|400px]]		[[File:Docker on Windows.png\|400px]]

	=Images=		=Images=
	Image a made up of a manifest and layers.		Image a made up of a manifest and layers.

Iwiseman: /* Images */

2021-08-16T07:52:04Z

Images

← Older revision		Revision as of 07:52, 16 August 2021
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	<br>		<br>
	[[File:Docker on Windows.png\|400px]]		[[File:Docker on Windows.png\|400px]]
	==Images==		=Images=
	Image a made up of a manifest and layers.		Image a made up of a manifest and layers.
	===Getting Images===		==Getting Images==
	We can get images using the pull command. The command is two step. It reads the manifests and then pulls the layers checking that the hashes pulled match the manifest hashes.		We can get images using the pull command. The command is two step. It reads the manifests and then pulls the layers checking that the hashes pulled match the manifest hashes.
	<syntaxhighlight lang="bash">		<syntaxhighlight lang="bash">
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	redis latest sha256:cd0c68c5479f2db4b9e2c5fbfdb7a8acb77625322dd5b474578515422d3ddb59 aa4d65e670d6 3 weeks ago 105MB		redis latest sha256:cd0c68c5479f2db4b9e2c5fbfdb7a8acb77625322dd5b474578515422d3ddb59 aa4d65e670d6 3 weeks ago 105MB
	</syntaxhighlight>		</syntaxhighlight>
	===The Layers===		==The Layers==
	We can find where our layers are by using		We can find where our layers are by using
	<syntaxhighlight lang="bash">		<syntaxhighlight lang="bash">
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	docker image inspect redis		docker image inspect redis
	</syntaxhighlight>		</syntaxhighlight>
	===Registries===		==Registries==
	Where images live. By default Docker uses docker hub but you can use your own or other peoples. Docker divides registries between official and unofficial. Official images live at top of the namespace e.g docker.io/redis docker.lo/mysql. It is important to understand when pulling an image there are three components.		Where images live. By default Docker uses docker hub but you can use your own or other peoples. Docker divides registries between official and unofficial. Official images live at top of the namespace e.g docker.io/redis docker.lo/mysql. It is important to understand when pulling an image there are three components.
	*Registry - e.g. dockerio		*Registry - e.g. dockerio
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	*Use Small images		*Use Small images
	*Be explicit referencing images (:latest noooo!)		*Be explicit referencing images (:latest noooo!)

	=Containers Detail=		=Containers Detail=
	==Copy on Write==		==Copy on Write==

Iwiseman: /* Containers Detail */

2021-08-16T07:51:23Z

Containers Detail

← Older revision		Revision as of 07:51, 16 August 2021
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	*Use Small images		*Use Small images
	*Be explicit referencing images (:latest noooo!)		*Be explicit referencing images (:latest noooo!)
	==Containers Detail==		=Containers Detail=
	===Copy on Write===		==Copy on Write==
	As we know the container is a bunch of layers and the images are read-only. Only the read/write layer is writeable. When we change values in a running container we actually copy the original file and put it in the read/write layer. This is known as '''copy on write'''<br>		As we know the container is a bunch of layers and the images are read-only. Only the read/write layer is writeable. When we change values in a running container we actually copy the original file and put it in the read/write layer. This is known as '''copy on write'''<br>
	[[File:Docket Detail.png\|500px]]		[[File:Docket Detail.png\|500px]]
	===Microservices===		==Microservices==
	Perhaps the current buzz-word. Previously we built our apps to have all of the components on one server. With containers we can break these down into individual containers. The old way is referred to as a monolith. The new way is to separate services and connect them with well documented APIs.		Perhaps the current buzz-word. Previously we built our apps to have all of the components on one server. With containers we can break these down into individual containers. The old way is referred to as a monolith. The new way is to separate services and connect them with well documented APIs.
	<br>		<br>
	[[File:Docker monolith.png\|600px]]		[[File:Docker monolith.png\|600px]]
	===Helpful Commands===		==Helpful Commands==
	Some useful bits		Some useful bits
	<syntaxhighlight lang="bash">		<syntaxhighlight lang="bash">
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	docker container rm $(docker container ls -aq) -f		docker container rm $(docker container ls -aq) -f
	</syntaxhighlight>		</syntaxhighlight>

	=Container Logging=		=Container Logging=
	We can set the logging driver in daemon.json (alternatives Gelf, Splunk, Fluentd...) and override for a container by passing --log-driver and --log-opts.		We can set the logging driver in daemon.json (alternatives Gelf, Splunk, Fluentd...) and override for a container by passing --log-driver and --log-opts.

Iwiseman: /* Container Logging */

2021-08-16T07:50:47Z

Container Logging

← Older revision		Revision as of 07:50, 16 August 2021
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	docker container rm $(docker container ls -aq) -f		docker container rm $(docker container ls -aq) -f
	</syntaxhighlight>		</syntaxhighlight>
	==Container Logging==		=Container Logging=
	We can set the logging driver in daemon.json (alternatives Gelf, Splunk, Fluentd...) and override for a container by passing --log-driver and --log-opts.		We can set the logging driver in daemon.json (alternatives Gelf, Splunk, Fluentd...) and override for a container by passing --log-driver and --log-opts.
	<br>		<br>
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	docker logs <container>		docker logs <container>
	</syntaxhighlight>		</syntaxhighlight>

	=Docker Swarm=		=Docker Swarm=
	==Introduction==		==Introduction==

Iwiseman: /* Docker Swarm */

2021-08-16T07:50:26Z

Docker Swarm

← Older revision		Revision as of 07:50, 16 August 2021
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	docker logs <container>		docker logs <container>
	</syntaxhighlight>		</syntaxhighlight>
	==Docker Swarm==		=Docker Swarm=
	===Introduction===		==Introduction==
	Swarm has two parts, the orchestrator and the secure cluster. The orchestrator does the start stop elements of running containers, the secure cluster is a way to run a group of containers with mutual authentication and encryption between them.		Swarm has two parts, the orchestrator and the secure cluster. The orchestrator does the start stop elements of running containers, the secure cluster is a way to run a group of containers with mutual authentication and encryption between them.
	===Swarm mode===		==Swarm mode==
	With docker you can run containers as Single-engine mode or in something called Swarm mode. Whilst there a some notes on the options here I will leave detail for another day. This is just for awareness.		With docker you can run containers as Single-engine mode or in something called Swarm mode. Whilst there a some notes on the options here I will leave detail for another day. This is just for awareness.
	<syntaxhighlight lang="bash">		<syntaxhighlight lang="bash">
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	docker swarm unlock		docker swarm unlock
	</syntaxhighlight>		</syntaxhighlight>

	=Docker Networking=		=Docker Networking=
	==OSI Layers==		==OSI Layers==