Relax escaping of values to enable limited access to the shell for AppDynamnics config#911
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Relax escaping of values to enable limited access to the shell for AppDynamnics config#911
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…pDynamnics config [Previous PRs escaped configuration values for AppD](#870). This was done to support things like names with spaces and other characters that, if used, would result in a broken start command. The PR broke a use case which was documented for the node or tier name. In some cases, you may want to set the node or tier name to a dynamic value that is loaded at runtime so that you can incorporate things like the application instance index. For example `DCX:$(echo $VCAP_APPLICATION | jq -r '.application_name'):$(echo $VCAP_APPLICATION | jq -r '.instance_index')`. This new PR will use `Shellwords.escape(..)` on the value for all properties unless that property value contains what looks like a subshell `$(..)` or environment variable `${..}` reference. If it looks like a subshell or env variable is being referenced, we will not escape but just wrap the value in escaped quotes. We wrap it in escaped quotes in case the shell variable or subshell returns something which includes spaces. This is not perfect though, and you need to be careful if using subshell/env variables, you should ensure the output is properly escaped. For example: - `DCX:$(echo $VCAP_APPLICATION | jq -r '.application_name'):$(echo $VCAP_APPLICATION | jq -r '.instance_index')` - `$(echo 'Hello world!') and stuff` becomes `\"$(echo 'Hello world!') and stuff\"` - `--> ${SOME_VAR} <--` becomes `\"--> ${SOME_VAR} <--\"` Signed-off-by: Daniel Mikusa <dmikusa@vmware.com>
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…pDynamnics config (#911) [Previous PRs escaped configuration values for AppD](#870). This was done to support things like names with spaces and other characters that, if used, would result in a broken start command. The PR broke a use case which was documented for the node or tier name. In some cases, you may want to set the node or tier name to a dynamic value that is loaded at runtime so that you can incorporate things like the application instance index. For example `DCX:$(echo $VCAP_APPLICATION | jq -r '.application_name'):$(echo $VCAP_APPLICATION | jq -r '.instance_index')`. This new PR will use `Shellwords.escape(..)` on the value for all properties unless that property value contains what looks like a subshell `$(..)` or environment variable `${..}` reference. If it looks like a subshell or env variable is being referenced, we will not escape but just wrap the value in escaped quotes. We wrap it in escaped quotes in case the shell variable or subshell returns something which includes spaces. This is not perfect though, and you need to be careful if using subshell/env variables, you should ensure the output is properly escaped. For example: - `DCX:$(echo $VCAP_APPLICATION | jq -r '.application_name'):$(echo $VCAP_APPLICATION | jq -r '.instance_index')` - `$(echo 'Hello world!') and stuff` becomes `\"$(echo 'Hello world!') and stuff\"` - `--> ${SOME_VAR} <--` becomes `\"--> ${SOME_VAR} <--\"` Signed-off-by: Daniel Mikusa <dmikusa@vmware.com>
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Previous PRs escaped configuration values for AppD. This was done to support things like names with spaces and other characters that, if used, would result in a broken start command.
The PR broke a use case which was documented for the node or tier name. In some cases, you may want to set the node or tier name to a dynamic value that is loaded at runtime so that you can incorporate things like the application instance index. For example
DCX:$(echo $VCAP_APPLICATION | jq -r '.application_name'):$(echo $VCAP_APPLICATION | jq -r '.instance_index').This new PR will use
Shellwords.escape(..)on the value for all properties unless that property value contains what looks like a subshell$(..)or environment variable${..}reference. If it looks like a subshell or env variable is being referenced, we will not escape but just wrap the value in escaped quotes. We wrap it in escaped quotes in case the shell variable or subshell returns something which includes spaces. This is not perfect though, and you need to be careful if using subshell/env variables, you should ensure the output is properly escaped.For example:
DCX:$(echo $VCAP_APPLICATION | jq -r '.application_name'):$(echo $VCAP_APPLICATION | jq -r '.instance_index')$(echo 'Hello world!') and stuffbecomes\"$(echo 'Hello world!') and stuff\"--> ${SOME_VAR} <--becomes\"--> ${SOME_VAR} <--\"Resolves #904
Signed-off-by: Daniel Mikusa dmikusa@vmware.com