Change:
<ins> /* Copyright 2016 The Kubernetes Authors. Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. */ package cmd import ( "bytes" "fmt" "io" "os" "github.com/spf13/cobra" "k8s.io/apimachinery/pkg/apis/meta/v1" cmdutil "k8s.io/kubernetes/pkg/kubectl/cmd/util" "k8s.io/kubernetes/pkg/kubectl/cmd/util/editor" "k8s.io/kubernetes/pkg/kubectl/resource" ) // NewCmdEditConfigMap is a macro command to edit config maps func NewCmdEditConfigMap(f cmdutil.Factory, cmdOut, errOut io.Writer) *cobra.Command { options := &resource.FilenameOptions{} cmd := &cobra.Command{ Use:     "configmap", Aliases: []string{"cm"}, Short:   "Edit a config map object.", Long:    "Edit and update a config map object", Run: func(cmd *cobra.Command, args []string) { RunEditConfigMap(cmd, f, args, cmdOut, errOut, options) }, } addEditFlags(cmd, options) cmd.Flags().String("config-map-data", "", "If non-empty, specify the name of a data slot in a config map to edit.") return cmd } // RunEditConfigMap runs the edit command for config maps. It either edits the complete map // or it edits individual files inside the config map. func RunEditConfigMap(cmd *cobra.Command, f cmdutil.Factory, args []string, cmdOut, errOut io.Writer, options *resource.FilenameOptions) error { dataFile := cmdutil.GetFlagString(cmd, "config-map-data") if len(dataFile) == 0 { // We need to add the resource type back on to the front args = append([]string{"configmap"}, args...) return RunEdit(f, cmdOut, errOut, cmd, args, options) } cmdNamespace, _, err := f.DefaultNamespace() if err != nil { return err } cs, err := f.ClientSet() if err != nil { return err } configMap, err := cs.Core().ConfigMaps(cmdNamespace).Get(args[0], v1.GetOptions{}) if err != nil { return err } value, found := configMap.Data[dataFile] if !found { keys := []string{} for key := range configMap.Data { keys = append(keys, key) } return fmt.Errorf("No such data file (%s), filenames are: %vn", dataFile, keys) } edit := editor.NewDefaultEditor(os.Environ()) data, file, err := edit.LaunchTempFile(fmt.Sprintf("%s-edit-", dataFile), "", bytes.NewBuffer([]byte(value))) defer func() { os.Remove(file) }() if err != nil { return err } configMap.Data[dataFile] = string(data) if _, err := cs.Core().ConfigMaps(cmdNamespace).Update(configMap); err != nil { return err } return nil } </ins>

Discussion:
Kubernetes version : What happened: When I try to display configmap content with yaml output (kubectl get configmap webapp-inifile -o yaml), the output is sometimes pretty, and sometimes not -depending newlines are effectively displayed or not - just n char- I can't find what's the difference between some file and some others. (limit on numer of lines ?) Configmap is created with --from-file option Ex : What you expected to happen: More human readable display, in order to be able to easily change parameter when kubectl edit congifmap How to reproduce it :
Hrm, this seems to me like the right answer is to special case 'kubectl edit' for configmaps, rather than try to hack around with the YAML decoder. I suppose we could use block quotes (e.g. ) if we see newlines but that seems error prone...
Closing this, pretty print is there, kubectl configMap edit support is there.
This still happens on kube 1.7 :-( I'm not 100% sure how to reproduce, but what I did was: have an existing configmap and edit a few lines exit the editor ... now I see the characters instead of actual newlines. even shows the characters
I'm also seeing this issue in kube 1.7. During the past few days I have edited a configmap ~110 times, and seen the formatting get destroyed (spaces messed up, characters visible) twice. I can't determine anything specific that I did in those two edits that would have triggered the formatting messup.
I'm still seeing this issue too. Pushed a lot of identical configmaps, some ones are displaying good, and some other bad. For example, I have a configmap with 3 files in ; they all are identical except one variable ; 2 of them display normally, and the last one displays with n ...
also seeing this issue on 1.7
can we reopen this issue? or open a new one?
I created a brand new configmap using and when I viewed the yaml with it's full of n characters and escape characters. This makes it very difficult to edit.
I am experiencing the same. n character is messing up a configmap I'm creating with --from-file option. Anyone found a reason why this is happening ?

Also failing in 1.8.4
I am also facing the same issue of formatting .. I have a application configuration of 400-500 lines. Tryied many times. For fist 40-50 lines the format is good ans easily readable.. However, when i try to create config for entire configuration file its very difficult to edit the config map..
Same issue here. No idea what makes one configmap show better than another.
This issue corrupted my aws-auth configMap that authenticates my user to access the EKS cluster and while trying to add other users to the configMap the formatting corrupted the configMap file and now I am locked out of my EKS cluster. Version: 1.10.3
I don't know if this will help somebody else but I was facing the same issue with escaped data in a config map edit and get (the config map had a single .conf file), and it seems that I had a unneeded extra space at the end of a single line in my data. When I removed that extra space the pretty printing was maintained in edit and get.
11 Still same
still same ( there is an example if install helm install stable/prometheus , you will find cm/prometheus-server )
I agree with - I can recreate it every time If you were to execute the following (ensuring no trailing spaces), the configmap remains "pretty" However, repeat the above (or edit the existing one with ), and put a trailing space after one of the key/value pairs, and that then messes up the configmap contents
Can we reopen this issue? I need this feature to change the yaml in cm, and I have been struggling with the intent and n for several days ...
Please reopen this ticket, it's incredibly frustrating to have to deal with this even on small configmaps
Got this also. I had to remove tabs from my config file to get the yaml multiline display.
Just created a messed up configmap on kuberntes 1.12.2.
Likewise.
OMG thank you!
Just ran into this in EKS (1.10.3) -- highly annoying. I have one config map that will come out OK if I use create directly, but if I pipe the output of to apply then it gets munged. Does seem like this is something that needs addressing.

Have the same issue and fixed by removing tabs
Have the same issue, don't have any tabs in file. This issue totally should be reopened.
This issue is valid and I am not sure why it was closed
Not only spaces. Trail symbols too. I uses vim for it
"n n" (spaces between end of lines) in one of my files also messed up the pretty display.
Created a new issue when I hit this again and was able to repro using the trailing whitespace
I've removed all the trailing whitespaces and tabs. The problem is gone.
Check any possible special chars. It solve my problem some time ago
I have seen this issue in K8 1.7 -1.13 kubectl create configmap NAMESPACE --from-file=$PATCHFILE --dry-run=true --output=yaml where PATCHFILE is attached file below. I renamed it from .json to .log so this webpage would let me include it.
Solve the issue by delete whitespace at each end of line.
The output of is ugly. Wether using json or yaml, k8s injects a whole bunch of escape characters and messes up the formatting of the original config file. It would be very nice to have a switch that tells it to dump the config out "normally"!
I a new line in a configMap using Tab for identation. After changing to Spaces instead of Tab, I was able to see the configmap as expected...
Same here, white space/s at the end of line ruin the output, everything back to pretty when white space/s removed.
This worked for me.
Since I've still met this on 1.16, I'll point a bullet list of the regular culprits for the configmap messing: spaces before newline:Tabs:Special characters like ãẽõ, áéó, öß will also mess your files. Look up for them in your comments, they might pass through!
An easy one liner to remove trailing whitespaces in a ConfigMap:
Please reopen. This issue still remains. This format makes eks aws-auth configmap very hard to maintain. Once the file is applied with trailing whitespaces the whole thing gets lots of n and . As a temporary measurement is there a way to reformat the configmap in the "readable" way? after the n are created?

if you use way didn't reformat the file for me.
Nurza's method works. But you may have a space before EOF as well: Or you may have CR's in there , in which case you should remove the CRs. Or you may have a TAB, which you should replace with one or more spaces.
No CR/TAB/new lines. I have a "clean" file that after I apply it all works great. (display as expected) After I add one trailing white space to it, it gets those n. I tried to run Nurza's method but it didn't work. Any other Ideas why Nurza's method is not working for me ? This a part of the output I'm getting with
has a space after it, although you don't see it. Because the LF is on the next line, there must be a space before it.
Correct but if I run Nurza's method the n are still there. Am I still missing anything? This is what I run
Nobody said that sed expression was perfect. Once you know this is your doing -- and you know how to fix it -- you're not bothered by this behaviour anymore.
This is scary shit :hankey: ... what is the industry practice to edit the file like these: aws-auth...? I managed to type 20+lines by hand :disappointed: and it worked on 3rd attempt :disappointed_relieved:
Cant' say about the 'like this', but aws-auth you can use eksctl to do the hard work for you:
If the formatting of cm goes wierd a simple hack to get it back to normal is : kubectl get cm configmapname -o yaml cm.yamlNow copy the contents of file and past it on is powerful tool to check the linting of yaml files. This will provide you with the configmap as expected with correct formatting. Paste the output in another yaml file (for e.g - )kubectl apply -f
Anyone knows why the issue is closed? It's not fixed as far as I can tell.

If you just want the raw output as it was read in when created --from-file, you can use jq to get the raw string (without escaped newlines etc) If you created a configmap from a file like this: Get the data:
Edited a cm, came back in, and had n all over. Something about white space in my previous edit? Not great overall :/ On kubectl version Client Version: version.Info{Major:"1", Minor:"18", GitVersion:"v1.18.5", GitCommit:"", GitTreeState:"clean", BuildDate:"2020-07-04T15:01:15Z", GoVersion:"go1.14.4", Compiler:"gc", Platform:"darwin/amd64"} Server Version: version.Info{Major:"1", Minor:"15", GitVersion:"v1.15.6", GitCommit:"", GitTreeState:"clean", BuildDate:"2019-11-13T11:11:50Z", GoVersion:"go1.12.12", Compiler:"gc", Platform:"linux/amd64"}
Awesome, very good website~
Thank You very much
I was able to fix this behavior by: 1) Don't use tabs, convert to spaces 2) To remove spaces before a newline character, use this: It will also convert CRLF to LF only, by removing .
Something small that exacerbates this issue is that in python's standard lib module , up to some version (I think python 3.4, see ), pretty printing adds a trailing space after every comma by default, unless you supply a list of separators yourself that omit the spaces (e.g. like ) So if you have old-ish glue (e.g. python 2.7) that parses a k8s configmap into a file for archival purposes, and you made that file readable by pretty-printing it, using that file to regenerate a new configmap results in this gross escape behaviour.
Hello There, One of our colleague has edited configmap with wrong data, now whole cluster inaccessible with any of role, need help on immediate basis and much appreciated. Error: through eksctl - Error: getting auth ConfigMap: Unauthorized through kubectl error: You must be logged in to the server (Unauthorized)
yaml marshallers will write a string to a multiline string e.g.

UNLESS string contains a character string terminates in a space character string contains a substring which matches the regex
I am in the same situation. Were you able to solve this?
Also reproduce in v1.22.3 :(
I occasionally encountered this problem in v1.15.6 or v1.21.2, but eventually I was able to deal with it by using edit and then using vim's own set list to back-propagate the original static configmap code configuration under gitlab to see if there were extra spaces, and then modifying the local configmap file based on the online configmap's set list display under edit. The state of the online configmap under edit, to modify the local configmap file, is ultimately able to deal with this problem, but if there is a better official way to do it would be good.
yes if you are working on linux
i would like to share an observation that helped me sort out the line merging and n. it appears to be related to the last line of the file you are using (--from-) if the last line ends with empty space or tab. the config map is merged up in one line with n as line feed if you remove the empty space from the last line, the ConfigMap will import file as is with +
I got the same error after editing the ConfigMap file. I used an online tool to remove the trailing white space that we cannot see in the text. After copying the content which removed trailing whitespaces I was able to resolve this issue FYI - (online tool which I used)
in v1.24 also i can see same issue. how we can edit cm with many lines.
Finally, I found that the absence of a value defined or the value is empty string in will cause the issue. data: {{ }} is not defined in my yaml just use quote to the value resolved
delete space before n or after n it works for me
did anyone find solution when we edit cm how we can see in proper format as for me really difficult to edit cm as we have many n char and I can still see this issue in k8s version 1.28