Docker ya aiki ta kuma ya fita jiya?

Question

IT Interview Practice · Accepted Answer

Docker tana amfani da Linux kernel features — **namespaces** (ka'idoji), **cgroups** (sarrafa albarkatun), da **union filesystems** (siffofin layered) — don yin hauhawar containers. Fahimtar niyoyin da suka ƙarƙata ya bayyana yadda containers ke samun ka'idoji da saurin aiki.

## Namespaces — ka'idoji

```text
Linux NAMESPACES isolate what a process can SEE — giving each container its own view:
  PID namespace     → its own process tree (container sees only its processes)
  NET namespace     → its own network interfaces, IPs, ports
  MNT namespace     → its own filesystem mounts
  UTS namespace     → its own hostname
  IPC, USER namespaces → isolated IPC, user/group ID mapping
→ Namespaces are WHY a container feels like a separate machine (isolated view),
  while actually sharing the host kernel.
```

## cgroups — sarrafa albarkatun

```text
Control Groups (CGROUPS) LIMIT and account for resource usage per container:
  → CPU, memory, disk I/O, network bandwidth
→ cgroups are WHY you can set resource limits (-m, --cpus) — the kernel enforces them.
```

## Union filesystem — siffofin layered

```text
UNION/OVERLAY filesystems (overlayfs) stack image LAYERS:
  → read-only image layers + a thin writable container layer on top, merged into one view
  → layers are SHARED between images/containers (one copy on disk) → space-efficient
→ This is WHY images are layered, cached, and shareable, and containers are lightweight.
```

## Gidan aiki

```text
Docker CLI → Docker DAEMON (dockerd) → containerd → runc (creates containers using
  namespaces + cgroups). The daemon manages images, containers, networks, volumes.
→ Containers are just ISOLATED PROCESSES on the host (not VMs) — using kernel features,
  sharing the host kernel → lightweight and fast.
```

## Dalilin abin mahimmanci

Fahimtar yadda Docker ya aiki a bita shi ne ilmin matakin gida mai kimar yada yadda **ya filli haure** da ya bayyana asalin abubuwan da suke mahimmanci (ka'idoji, saurin aiki, sarrafa albarkatun), wanda ke dagula gida na tunani, tabbatarwa, da warwarewa kan systems da aka sanya a cikin containers.

Mahimmin fahimta shi ne **containers ba su da VMs — suna cikin tarar aiki sai da fukan gida** ta amfani da Linux kernel features, wanda yasa suna hawau da sauri (bayar da kernel na gida maimakon lokanta kabar OS).

Fahimtar **halin mahimmanci gida uku** ya bayyana asali: **namespaces** suna ka'idoji abin da tarar aiki zai iya gani (jikin tarar aiki na kanta, hanyar sadarwa, tsarin fayiloli, sunan maimaitawa — wanda yasa container ya ji kamar injin daban daban duk da raba kernel), **cgroups** suna karkatarwa da lissafin loƙin albarkatun (wanda yasa kuka iya saita CPU da kulli na ƙaura — kernel ya tilaste su), da **union/overlay filesystems** suna ţaka siffofin hoton (wanda yasa hotuna suna da siffofin layered, cached, da sharewa, da containers suna hawau — faran karkatawa da raba da container guda lɗo tare da filin ɗan saurin saurin).n
Fahimtar **gidan aiki** (CLI → daemon → containerd → runc, tare da daemon yana sarrafa duka) ya ba da kamammen hotuna na yadda Docker ke aiki.

Fahimta mai zurfin yawu ta taimaka wajen tunanin kulli-dawaɗi (da jiya niyoyin aminci, tun da containers sun raba kernel), ya bayyana halayen karfin aiki da saurin aiki, da taimakawa warwarewa.

Tun fahimta niyoyin da suka ƙarƙata (namespaces, cgroups, union filesystems) ya bayyana dalilin containers ke aikin su — their ka'idoji, saurin aiki, sarrafa albarkatun, da mahimmin gida cewa suna raba kernel na gida (tare da jiya niyoyin aminci) — da dagula gida na aiki tare da containers tare da azintarwa, fahimta yadda Docker ya aiki jiya shi ne ilmin matakin gida mai kimar yada yadda ya tashi daga amfani da Docker zuwa fahimta duka, jirgin jiya da ya nuna zurfin da ake buƙata don matakin gida da mu'amala ga tunanin halayen container, kulli-dawaɗi aminci, da karfin aiki.

Namespaces — ka'idoji

cgroups — sarrafa albarkatun

Union filesystem — siffofin layered

Gidan aiki

Dalilin abin mahimmanci

Tambayoyi masu alaƙa