Using sed with command-substitution text in the replacement part is not working
I have a CFN with cfn-init to deploy a Apache web server with specified virtual hosts. In the template, I use a AWS::CloudFormation::Init configset to replace local IPs with the Instance's private IP.
config:
packages:...
files:...
services:...
commands:
replacePrivateIP:
cwd: "/etc/httpd/conf"
command: !Sub |
sed -i 's@127.0.0.1@$(curl -s http://169.254.169.254/latest/meta-data/local-ipv4)@g' httpd.conf
The sed command works fine outside the CFN template. But in the CFN-init process, it simply replace "127.0.0.1" with the whole $(curl -s http://...) string.
How can I feed the instance private IP correctly into the httpd.conf file through cfn-init?
sed
edited Dec 28 '18 at 12:19
Inian
38.9k63770
asked Dec 28 '18 at 11:11
Tomking ChenTomking Chen
327
add a comment |
I have a CFN with cfn-init to deploy a Apache web server with specified virtual hosts. In the template, I use a AWS::CloudFormation::Init configset to replace local IPs with the Instance's private IP.
config:
packages:...
files:...
services:...
commands:
replacePrivateIP:
cwd: "/etc/httpd/conf"
command: !Sub |
sed -i 's@127.0.0.1@$(curl -s http://169.254.169.254/latest/meta-data/local-ipv4)@g' httpd.conf
The sed command works fine outside the CFN template. But in the CFN-init process, it simply replace "127.0.0.1" with the whole $(curl -s http://...) string.
How can I feed the instance private IP correctly into the httpd.conf file through cfn-init?
sed
edited Dec 28 '18 at 12:19
Inian
38.9k63770
asked Dec 28 '18 at 11:11
Tomking ChenTomking Chen
327
add a comment |
I have a CFN with cfn-init to deploy a Apache web server with specified virtual hosts. In the template, I use a AWS::CloudFormation::Init configset to replace local IPs with the Instance's private IP.
config:
packages:...
files:...
services:...
commands:
replacePrivateIP:
cwd: "/etc/httpd/conf"
command: !Sub |
sed -i 's@127.0.0.1@$(curl -s http://169.254.169.254/latest/meta-data/local-ipv4)@g' httpd.conf
The sed command works fine outside the CFN template. But in the CFN-init process, it simply replace "127.0.0.1" with the whole $(curl -s http://...) string.
How can I feed the instance private IP correctly into the httpd.conf file through cfn-init?
sed
edited Dec 28 '18 at 12:19
Inian
38.9k63770
asked Dec 28 '18 at 11:11
Tomking ChenTomking Chen
327
I have a CFN with cfn-init to deploy a Apache web server with specified virtual hosts. In the template, I use a AWS::CloudFormation::Init configset to replace local IPs with the Instance's private IP.
config:
packages:...
files:...
services:...
commands:
replacePrivateIP:
cwd: "/etc/httpd/conf"
command: !Sub |
sed -i 's@127.0.0.1@$(curl -s http://169.254.169.254/latest/meta-data/local-ipv4)@g' httpd.conf
The sed command works fine outside the CFN template. But in the CFN-init process, it simply replace "127.0.0.1" with the whole $(curl -s http://...) string.
How can I feed the instance private IP correctly into the httpd.conf file through cfn-init?
sed
sed
edited Dec 28 '18 at 12:19
Inian
38.9k63770
asked Dec 28 '18 at 11:11
Tomking ChenTomking Chen
327
edited Dec 28 '18 at 12:19
Inian
38.9k63770
asked Dec 28 '18 at 11:11
Tomking ChenTomking Chen
327
edited Dec 28 '18 at 12:19
Inian
38.9k63770
edited Dec 28 '18 at 12:19
Inian
38.9k63770
edited Dec 28 '18 at 12:19
Inian
38.9k63770
38.9k63770
asked Dec 28 '18 at 11:11
Tomking ChenTomking Chen
327
asked Dec 28 '18 at 11:11
Tomking ChenTomking Chen
327
asked Dec 28 '18 at 11:11
Tomking ChenTomking Chen
327
327
add a comment |
add a comment |
1 Answer
1
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The command-substitution syntax $(..) does not work when wrapped in single quotes which is as expected in bash or most other shells as they preserve the literal value present inside. For your substitution to happen, put it inside double-quotes as
sed -i 's@127.0.0.1@'"$(curl -s http://169.254.169.254/latest/meta-data/local-ipv4)"'@g' httpd.conf
Compare the outputs of echo '$(date)' and echo "$(date)" for a simple example of your case.
answered Dec 28 '18 at 12:18
InianInian
38.9k63770
add a comment |
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1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
The command-substitution syntax $(..) does not work when wrapped in single quotes which is as expected in bash or most other shells as they preserve the literal value present inside. For your substitution to happen, put it inside double-quotes as
sed -i 's@127.0.0.1@'"$(curl -s http://169.254.169.254/latest/meta-data/local-ipv4)"'@g' httpd.conf
Compare the outputs of echo '$(date)' and echo "$(date)" for a simple example of your case.
answered Dec 28 '18 at 12:18
InianInian
38.9k63770
add a comment |
The command-substitution syntax $(..) does not work when wrapped in single quotes which is as expected in bash or most other shells as they preserve the literal value present inside. For your substitution to happen, put it inside double-quotes as
sed -i 's@127.0.0.1@'"$(curl -s http://169.254.169.254/latest/meta-data/local-ipv4)"'@g' httpd.conf
Compare the outputs of echo '$(date)' and echo "$(date)" for a simple example of your case.
answered Dec 28 '18 at 12:18
InianInian
38.9k63770
add a comment |
The command-substitution syntax $(..) does not work when wrapped in single quotes which is as expected in bash or most other shells as they preserve the literal value present inside. For your substitution to happen, put it inside double-quotes as
sed -i 's@127.0.0.1@'"$(curl -s http://169.254.169.254/latest/meta-data/local-ipv4)"'@g' httpd.conf
Compare the outputs of echo '$(date)' and echo "$(date)" for a simple example of your case.
answered Dec 28 '18 at 12:18
InianInian
38.9k63770
The command-substitution syntax $(..) does not work when wrapped in single quotes which is as expected in bash or most other shells as they preserve the literal value present inside. For your substitution to happen, put it inside double-quotes as
sed -i 's@127.0.0.1@'"$(curl -s http://169.254.169.254/latest/meta-data/local-ipv4)"'@g' httpd.conf
Compare the outputs of echo '$(date)' and echo "$(date)" for a simple example of your case.
answered Dec 28 '18 at 12:18
InianInian
38.9k63770
edited Dec 28 '18 at 12:23
answered Dec 28 '18 at 12:18
InianInian
38.9k63770
answered Dec 28 '18 at 12:18
InianInian
38.9k63770
answered Dec 28 '18 at 12:18
InianInian
38.9k63770
38.9k63770
add a comment |
add a comment |
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