How Can You Perform Variable Substitution using Kubectl?
I am trying to create a Role and RoleBinding so I can use Helm. I want to use variable substitution somehow to replace {{namespace}} with something when I run an apply command.
kind: Role
apiVersion: rbac.authorization.k8s.io/v1
metadata:
name: tiller-manager-{{namespace}}
namespace: {{namespace}}
rules:
- apiGroups: ["", "batch", "extensions", "apps"]
resources: ["*"]
verbs: ["*"]
I want to pass the namespace something like this:
kubectl apply --file role.yaml --namespace foo
I have seen that kubectl apply has a --template parameter but I can't see much information about how it might be used.
kubernetes kubectl asked Nov 13 at 16:49
Muhammad Rehan Saeed
11.6k9108182
add a comment |
I am trying to create a Role and RoleBinding so I can use Helm. I want to use variable substitution somehow to replace {{namespace}} with something when I run an apply command.
kind: Role
apiVersion: rbac.authorization.k8s.io/v1
metadata:
name: tiller-manager-{{namespace}}
namespace: {{namespace}}
rules:
- apiGroups: ["", "batch", "extensions", "apps"]
resources: ["*"]
verbs: ["*"]
I want to pass the namespace something like this:
kubectl apply --file role.yaml --namespace foo
I have seen that kubectl apply has a --template parameter but I can't see much information about how it might be used.
kubernetes kubectl asked Nov 13 at 16:49
Muhammad Rehan Saeed
11.6k9108182
1
For what you’ve shown here, you don’t need to specify the namespace in the YAML file:kubectlhas a--namespaceoption to fill that item in, and since resource names are namespace-scoped, you can have the same role name in multiple namespaces safely.
– David Maze
Nov 13 at 18:53
But I'm using the namespace to also modify the name.
– Muhammad Rehan Saeed
Nov 14 at 10:32
add a comment |
I am trying to create a Role and RoleBinding so I can use Helm. I want to use variable substitution somehow to replace {{namespace}} with something when I run an apply command.
kind: Role
apiVersion: rbac.authorization.k8s.io/v1
metadata:
name: tiller-manager-{{namespace}}
namespace: {{namespace}}
rules:
- apiGroups: ["", "batch", "extensions", "apps"]
resources: ["*"]
verbs: ["*"]
I want to pass the namespace something like this:
kubectl apply --file role.yaml --namespace foo
I have seen that kubectl apply has a --template parameter but I can't see much information about how it might be used.
kubernetes kubectl asked Nov 13 at 16:49
Muhammad Rehan Saeed
11.6k9108182
I am trying to create a Role and RoleBinding so I can use Helm. I want to use variable substitution somehow to replace {{namespace}} with something when I run an apply command.
kind: Role
apiVersion: rbac.authorization.k8s.io/v1
metadata:
name: tiller-manager-{{namespace}}
namespace: {{namespace}}
rules:
- apiGroups: ["", "batch", "extensions", "apps"]
resources: ["*"]
verbs: ["*"]
I want to pass the namespace something like this:
kubectl apply --file role.yaml --namespace foo
I have seen that kubectl apply has a --template parameter but I can't see much information about how it might be used.
kubernetes kubectl kubernetes kubectl asked Nov 13 at 16:49
Muhammad Rehan Saeed
11.6k9108182
asked Nov 13 at 16:49
Muhammad Rehan Saeed
11.6k9108182
asked Nov 13 at 16:49
Muhammad Rehan Saeed
11.6k9108182
asked Nov 13 at 16:49
Muhammad Rehan Saeed
11.6k9108182
asked Nov 13 at 16:49
Muhammad Rehan Saeed
11.6k9108182
11.6k9108182
1
For what you’ve shown here, you don’t need to specify the namespace in the YAML file:kubectlhas a--namespaceoption to fill that item in, and since resource names are namespace-scoped, you can have the same role name in multiple namespaces safely.
– David Maze
Nov 13 at 18:53
But I'm using the namespace to also modify the name.
– Muhammad Rehan Saeed
Nov 14 at 10:32
add a comment |
1
For what you’ve shown here, you don’t need to specify the namespace in the YAML file:kubectlhas a--namespaceoption to fill that item in, and since resource names are namespace-scoped, you can have the same role name in multiple namespaces safely.
– David Maze
Nov 13 at 18:53
But I'm using the namespace to also modify the name.
– Muhammad Rehan Saeed
Nov 14 at 10:32
1
1
For what you’ve shown here, you don’t need to specify the namespace in the YAML file:
kubectl has a --namespace option to fill that item in, and since resource names are namespace-scoped, you can have the same role name in multiple namespaces safely.– David Maze
Nov 13 at 18:53
For what you’ve shown here, you don’t need to specify the namespace in the YAML file:
kubectl has a --namespace option to fill that item in, and since resource names are namespace-scoped, you can have the same role name in multiple namespaces safely.– David Maze
Nov 13 at 18:53
But I'm using the namespace to also modify the name.
– Muhammad Rehan Saeed
Nov 14 at 10:32
But I'm using the namespace to also modify the name.
– Muhammad Rehan Saeed
Nov 14 at 10:32
add a comment |
2 Answers
2
active
oldest
votes
You can do it in following way.
Write
Rolefile like this:
kind: Role
apiVersion: rbac.authorization.k8s.io/v1
metadata:
name: tiller-manager-${NAMESPACE}
namespace: ${NAMESPACE}
rules:
- apiGroups: ["", "batch", "extensions", "apps"]
resources: ["*"]
verbs: ["*"]
Set
NAMESPACEenvironment variable to your desired value.
Then create Role using following command
envsubst < role.yaml | kubectl apply -f -
answered Nov 13 at 17:00
Emruz Hossain
1,084210
I guess I have to installenvsubstthough first.
– Muhammad Rehan Saeed
Nov 13 at 17:04
If you are using linux, it is already installed.
– Emruz Hossain
Nov 13 at 17:05
If you are using Mac check answer from this: stackoverflow.com/questions/23620827/…
– Emruz Hossain
Nov 13 at 17:09
add a comment |
Another way you can use. With sed command you can replace {{namespace}} directly. without setting any environment variable or using envsubst.
- First save your role in a file say
role.yamlwhich contains original content. - Then use
sed 's/{{namespace}}/your-namespace-name/g' role.yaml. which print instdoutthe desired file. Replaced{{namespace}}withyour-namespace-name.
N.B: you can also save it in a file using sed 's/{{namespace}}/your-namespace-name/g' role.yaml > new-role.yaml
answered Nov 15 at 6:40
Abu Hanifa
746922
add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
You can do it in following way.
Write
Rolefile like this:
kind: Role
apiVersion: rbac.authorization.k8s.io/v1
metadata:
name: tiller-manager-${NAMESPACE}
namespace: ${NAMESPACE}
rules:
- apiGroups: ["", "batch", "extensions", "apps"]
resources: ["*"]
verbs: ["*"]
Set
NAMESPACEenvironment variable to your desired value.
Then create Role using following command
envsubst < role.yaml | kubectl apply -f -
answered Nov 13 at 17:00
Emruz Hossain
1,084210
I guess I have to installenvsubstthough first.
– Muhammad Rehan Saeed
Nov 13 at 17:04
If you are using linux, it is already installed.
– Emruz Hossain
Nov 13 at 17:05
If you are using Mac check answer from this: stackoverflow.com/questions/23620827/…
– Emruz Hossain
Nov 13 at 17:09
add a comment |
You can do it in following way.
Write
Rolefile like this:
kind: Role
apiVersion: rbac.authorization.k8s.io/v1
metadata:
name: tiller-manager-${NAMESPACE}
namespace: ${NAMESPACE}
rules:
- apiGroups: ["", "batch", "extensions", "apps"]
resources: ["*"]
verbs: ["*"]
Set
NAMESPACEenvironment variable to your desired value.
Then create Role using following command
envsubst < role.yaml | kubectl apply -f -
answered Nov 13 at 17:00
Emruz Hossain
1,084210
I guess I have to installenvsubstthough first.
– Muhammad Rehan Saeed
Nov 13 at 17:04
If you are using linux, it is already installed.
– Emruz Hossain
Nov 13 at 17:05
If you are using Mac check answer from this: stackoverflow.com/questions/23620827/…
– Emruz Hossain
Nov 13 at 17:09
add a comment |
You can do it in following way.
Write
Rolefile like this:
kind: Role
apiVersion: rbac.authorization.k8s.io/v1
metadata:
name: tiller-manager-${NAMESPACE}
namespace: ${NAMESPACE}
rules:
- apiGroups: ["", "batch", "extensions", "apps"]
resources: ["*"]
verbs: ["*"]
Set
NAMESPACEenvironment variable to your desired value.
Then create Role using following command
envsubst < role.yaml | kubectl apply -f -
answered Nov 13 at 17:00
Emruz Hossain
1,084210
You can do it in following way.
Write
Rolefile like this:
kind: Role
apiVersion: rbac.authorization.k8s.io/v1
metadata:
name: tiller-manager-${NAMESPACE}
namespace: ${NAMESPACE}
rules:
- apiGroups: ["", "batch", "extensions", "apps"]
resources: ["*"]
verbs: ["*"]
Set
NAMESPACEenvironment variable to your desired value.
Then create Role using following command
envsubst < role.yaml | kubectl apply -f -
answered Nov 13 at 17:00
Emruz Hossain
1,084210
answered Nov 13 at 17:00
Emruz Hossain
1,084210
answered Nov 13 at 17:00
Emruz Hossain
1,084210
answered Nov 13 at 17:00
Emruz Hossain
1,084210
1,084210
I guess I have to installenvsubstthough first.
– Muhammad Rehan Saeed
Nov 13 at 17:04
If you are using linux, it is already installed.
– Emruz Hossain
Nov 13 at 17:05
If you are using Mac check answer from this: stackoverflow.com/questions/23620827/…
– Emruz Hossain
Nov 13 at 17:09
add a comment |
I guess I have to installenvsubstthough first.
– Muhammad Rehan Saeed
Nov 13 at 17:04
If you are using linux, it is already installed.
– Emruz Hossain
Nov 13 at 17:05
If you are using Mac check answer from this: stackoverflow.com/questions/23620827/…
– Emruz Hossain
Nov 13 at 17:09
I guess I have to install
envsubst though first.– Muhammad Rehan Saeed
Nov 13 at 17:04
I guess I have to install
envsubst though first.– Muhammad Rehan Saeed
Nov 13 at 17:04
If you are using linux, it is already installed.
– Emruz Hossain
Nov 13 at 17:05
If you are using linux, it is already installed.
– Emruz Hossain
Nov 13 at 17:05
If you are using Mac check answer from this: stackoverflow.com/questions/23620827/…
– Emruz Hossain
Nov 13 at 17:09
If you are using Mac check answer from this: stackoverflow.com/questions/23620827/…
– Emruz Hossain
Nov 13 at 17:09
add a comment |
Another way you can use. With sed command you can replace {{namespace}} directly. without setting any environment variable or using envsubst.
- First save your role in a file say
role.yamlwhich contains original content. - Then use
sed 's/{{namespace}}/your-namespace-name/g' role.yaml. which print instdoutthe desired file. Replaced{{namespace}}withyour-namespace-name.
N.B: you can also save it in a file using sed 's/{{namespace}}/your-namespace-name/g' role.yaml > new-role.yaml
answered Nov 15 at 6:40
Abu Hanifa
746922
add a comment |
Another way you can use. With sed command you can replace {{namespace}} directly. without setting any environment variable or using envsubst.
- First save your role in a file say
role.yamlwhich contains original content. - Then use
sed 's/{{namespace}}/your-namespace-name/g' role.yaml. which print instdoutthe desired file. Replaced{{namespace}}withyour-namespace-name.
N.B: you can also save it in a file using sed 's/{{namespace}}/your-namespace-name/g' role.yaml > new-role.yaml
answered Nov 15 at 6:40
Abu Hanifa
746922
add a comment |
Another way you can use. With sed command you can replace {{namespace}} directly. without setting any environment variable or using envsubst.
- First save your role in a file say
role.yamlwhich contains original content. - Then use
sed 's/{{namespace}}/your-namespace-name/g' role.yaml. which print instdoutthe desired file. Replaced{{namespace}}withyour-namespace-name.
N.B: you can also save it in a file using sed 's/{{namespace}}/your-namespace-name/g' role.yaml > new-role.yaml
answered Nov 15 at 6:40
Abu Hanifa
746922
Another way you can use. With sed command you can replace {{namespace}} directly. without setting any environment variable or using envsubst.
- First save your role in a file say
role.yamlwhich contains original content. - Then use
sed 's/{{namespace}}/your-namespace-name/g' role.yaml. which print instdoutthe desired file. Replaced{{namespace}}withyour-namespace-name.
N.B: you can also save it in a file using sed 's/{{namespace}}/your-namespace-name/g' role.yaml > new-role.yaml
answered Nov 15 at 6:40
Abu Hanifa
746922
answered Nov 15 at 6:40
Abu Hanifa
746922
answered Nov 15 at 6:40
Abu Hanifa
746922
answered Nov 15 at 6:40
Abu Hanifa
746922
746922
add a comment |
add a comment |
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1
For what you’ve shown here, you don’t need to specify the namespace in the YAML file:
kubectlhas a--namespaceoption to fill that item in, and since resource names are namespace-scoped, you can have the same role name in multiple namespaces safely.– David Maze
Nov 13 at 18:53
But I'm using the namespace to also modify the name.
– Muhammad Rehan Saeed
Nov 14 at 10:32