Creating ConfigMaps from literals in Kubernetes - Visual Walkthrough

Process Flow - Creating ConfigMaps from literals

Start

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Run kubectl create configmap with --from-literal

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kubectl parses literals

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ConfigMap object created in memory

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ConfigMap stored in Kubernetes cluster

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ConfigMap ready to be used by pods

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End

This flow shows how a ConfigMap is created from literal key-value pairs using kubectl, stored in the cluster, and made available for pods.

Execution Sample

Kubernetes

kubectl create configmap my-config --from-literal=key1=value1 --from-literal=key2=value2

Creates a ConfigMap named 'my-config' with two keys and their literal values.

Process Table

Step	Action	Input/Command	Result
1	Start command	kubectl create configmap my-config --from-literal=key1=value1 --from-literal=key2=value2	Command accepted by kubectl
2	Parse literals	--from-literal=key1=value1, --from-literal=key2=value2	Parsed key1=value1 and key2=value2
3	Create ConfigMap object	Keys and values parsed	ConfigMap object with data {key1: value1, key2: value2} created in memory
4	Send to Kubernetes API	ConfigMap object	ConfigMap stored in cluster
5	Confirm creation	kubectl output	configmap/my-config created
6	End	N/A	ConfigMap 'my-config' ready for use

💡 ConfigMap creation completes successfully and is stored in the cluster.

Status Tracker

Variable	Start	After Step 2	After Step 3	Final
Command Input	N/A	kubectl create configmap my-config --from-literal=key1=value1 --from-literal=key2=value2	N/A	N/A
Parsed Literals	Empty	{key1: value1, key2: value2}	{key1: value1, key2: value2}	{key1: value1, key2: value2}
ConfigMap Object	None	None	Created with data	Stored in cluster

Key Moments - 3 Insights

Why do we use --from-literal instead of a file?

Using --from-literal lets you quickly create ConfigMaps with small key-value pairs directly from the command line, as shown in step 2 of the execution_table.

What happens if you repeat the same key with different values?

kubectl will use the last value provided for that key when creating the ConfigMap object, as the parsed literals overwrite previous keys (see step 3).

How do we know the ConfigMap was created successfully?

kubectl outputs 'configmap/my-config created' at step 5, confirming the ConfigMap is stored and ready.

Visual Quiz - 3 Questions

Look at the execution_table, what is the result after parsing literals at step 2?

A Parsed key1=value1 and key2=value2

B ConfigMap stored in cluster

C Command accepted by kubectl

D ConfigMap object created in memory

💡 Hint

Check the 'Result' column at step 2 in the execution_table.

At which step does the ConfigMap object get created in memory?

A Step 2

B Step 3

C Step 4

D Step 5

💡 Hint

Look at the 'Action' column for when the ConfigMap object is created.

If you add another --from-literal=key1=newvalue, what changes in the variable_tracker?

A ConfigMap Object will be deleted

B Command Input will be empty

C Parsed Literals will have key1 with value 'newvalue' replacing 'value1'

D No change in Parsed Literals

💡 Hint

Refer to the 'Parsed Literals' row in variable_tracker and how keys overwrite previous values.

Concept Snapshot

kubectl create configmap <name> --from-literal=key=value [--from-literal=key2=value2 ...]
Creates a ConfigMap with literal key-value pairs.
Each --from-literal adds one key and value.
ConfigMap is stored in the cluster and can be used by pods.
Use this for quick small configs without files.

Full Transcript

This visual execution shows how to create a Kubernetes ConfigMap from literal key-value pairs using the kubectl command. The process starts by running the command with --from-literal flags. Kubectl parses these literals into key-value pairs, then creates a ConfigMap object in memory with this data. The object is sent to the Kubernetes API server and stored in the cluster. Kubectl confirms creation by outputting a success message. The ConfigMap is then ready to be used by pods. Key points include understanding that literals are parsed and stored as keys and values, and that repeated keys overwrite previous values. This method is useful for quick configuration without needing files.